Winter 2007 - Centre for Alternative Technology

The Practical Journal of Sustainable Living
Clean Slate
No 66 Winter 2007 £2.50
editorial Peter Harper
6
The Practical Journal of Sustainable Living
contents
CAT
CAT News – compiled by Arthur Girling
2
Roger’s Garden
4
WISE update
6
Diary of Events
14
27
Features
Earth Spirituality – Jaise Kuriakose
7
Climate change and gardening – Grace Crabb
11
Illegal vegetables and how to grow them – Chloë Ward
14
Flow batteries, a technology for storing elelctrical energy –
17
Arthur Butler
Practical Solutions
21
Practical Solutions –
compiled by Sophie Holdstock and Tatsuro Shigetomi
13
My Green Solution – CAT member, Ray Jones
27
Regulars
Questions and Answers: Zero Waste –
Melissa Harvey, CAT Information
20
Members’ Info:
Dumped. 3 weeks on a Croyden tip – Steve Jones
21
Members’ Corner:
Earthship France – Kevan and Gillian Trott
24
Members’ Letters
26
Reviews
28
24
Cover photo: Arthur Girling
Clean Slate is a member of INK, the independent News Collective,
trade association of the UK alternative press.
www.ink.uk.com
Canute the Great, one of England’s
tenth-century kings, is remembered
for a particularly dramatic act. Seated
on his throne, he had it carried down
to the seashore where the waves of a
rising tide lapped the sand. Sternly he
commanded the sea to stay where it
was, but of course it continued to rise
until it engulfed the throne. He wanted
to remind his flattering courtiers that
however great a king’s powers in the
world of men, they count for nothing
against the forces of nature.
Nature comes first, and policymakers are
still forgetting it. The recent evidence of
feedback effects in the climate system
has shown how close we might be to
triggering the release of enormous
quantities of natural greenhouse gases
locked in the sea and the biosphere. The
implications are severe but unavoidable:
a need to reduce human greenhouse-gas
emissions virtually to zero within twenty
years. Understandably perhaps, the
mainstream response is to ignore this as
‘politically and economically unrealistic’.
CAT’s response is zerocarbonbritain,
showing how the UK could take a
leading role in decarbonising the world
by decarbonising itself, quickly and
systematically. We’re with Canute:
start with the actual physical situation,
keep checking it, and work to create
technical, political and economic
solutions to fit. The alternative, to follow
the path of political expediency and
hope the environment will stop bothering
us, amounts to running away from
the problem. But there is no ‘away’.
Eventually, like Canute, we would be
engulfed – perhaps even literally! – by
the rising tide
Printed on 100% recycled paper. All four colour inks – Ramaspeed Eco Plus and Pantone® base colours used in the manufacture of this magazine are totally vegetable based
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CAT information line: 01654 705989
The Centre for Alternative Technology (CAT) is concerned with
the search for ecologically sustainable technologies and ways of
life. A display and education centre, researcher and information
provider, CAT aims to inspire, inform and enable people to reduce
their impact on the earth. Published by CAT Publications,
CAT Charity Ltd., Centre for Alternative Technology.
Editorial Team Paul Allen, Caroline Oakley, Scott Williams,
Arthur Girling, Hannah Davey, Fiona Rowe, Sophie Holdstock.
Design Graham Preston
Advertising Jo Cooper. The opinions expressed are those of
individual originators, not necessarily those of CAT. If you wish
to use material from Clean Slate for furthering the aims of the
environmental movement please contact the editor.
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The printing of an advert in Clean Slate does not mean that the
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Clean Slate catnews
CAT news in brief…
Viewing platform
Many of the displays in CAT’s
Visitor Centre demonstrate
techniques such as eco-building
on a small scale. But the latest
spectacle for visitors is three
storeys tall, and growing all the
time…
A new viewing platform
has been built for visitors to
watch the new £6.2million
Wales Institute for Sustainable
Education (WISE) under
construction in rammed earth,
timber and lime.
WISE is a three-storey
timber-frame building including
24 twin bedrooms for students,
classrooms, workshops, roof
gardens, a lecture theatre and
a bar, all built to the highest
environmental standard. Over
the next few months, visitors to
the centre will be able to watch
hemp-lime spraying, timber frame
construction and earth-ramming
using pneumatic hand-held
rammers. These techniques use
less energy than conventional
building methods, and reduce the
building’s energy demand.
The new viewing platform
incorporates a screen showing
videos about the building,
including a digital fly-through of
the finished structure. Display
boards also explain the building
techniques. Demonstrating an
innovative reusable design, the
platform will be dismantled and
rebuilt as a play area for children
when WISE is completed!
CAT visitors
CAT has had several notable
visitors over the summer.
The Tyndall Centre, a climate
change research organisation
based at Manchester University,
came to visit CAT in early July. A
team of 15 stayed in the Eco-
Clean Slate
compiled by Arthur Girling
Venezuelan government official visits CAT
zerocarbonbritain update
In July CAT published
Tim Helweg-Larsen and Michael Meacher
zerocarbonbritain, which recommends
a set of policies to bring the UK out of
fossil fuel dependency.
In the three months since the last
issue of Clean Slate, the report has
received an enthusiastic response from
all the major political parties.
Development Director Paul Allen
and Tim Helweg-Larsen from the
Public Interest Research Centre (PIRC)
presented the report at the Houses of
Parliament. The presentation dominated
recommends Britain eliminate all greenhouse gas
the AGM of the All Party Parliamentary Climate
emissions from fossil fuels as soon as possible
Change Group. The Liberal Democrats have even
– a scenario within the document demonstrates
named their new environment policy Zero Carbon the potential of making these drastic cuts within
Britain, citing CAT as a major influence.
20 years. To drive this shift, the authors have
Lembit Opik, Liberal Democrat MP for Powys
recommended a system of personal carbon
and Montgomeryshire, and Shadow Secretary
allowances, or Tradable Energy Quotas (TEQs,
of State for Business and Enterprise said: ‘These
pronounced ‘tecks’).
proposals were largely inspired by the Wales
Following its intial success, the authors
based Centre for Alternative Technology and I
plan to refine the project, working with other
would like to thank them for the ground-breaking
organisations to produce an annual report. But
work.’
why stop with Britain? The next report will look
The aim of zerocarbonbritain was to
at Europe, and reducing emissions to zero across
demonstrate a well-constructed solution to
the continent.
the interlinked issues of climate change,
Download the full report from
energy security and global equity. The report
www.zerocarbonbritain.com
CAT news in brief…
In August a Venezuelan government official visited CAT and the Dyfi Valley to exchange ideas on
environmental policy.
Dr Cesar Aponte, Director of Protected Areas from the Venzuelan Ministry for the Environment,
was visiting nearby Machynlleth to take part in a workshop and discussion named Oil, Equity and
Biospheres, held in association with CAT. The day-long event, on Friday 10th August, included talks
and a panel discussion, at which Dr Aponte spoke about oil-rich Venezuela’s environmental policies.
The South American country has made some radical moves to reduce energy use and protect the
natural environment, while encouraging access to energy for all sectors of the population.
One government scheme in Venezuela has exchanged 52 million incandescent light-bulbs for the
low-energy variety. Government-supported schemes like this are crucial in fighting climate change,
Dr Aponte said, but the impetus often comes from local campaigns and activists such as those
at CAT. ‘It is very important to have policies put in place by the government, and also
campaigners and education supporting these policies. We need pressure from above and
below.’
When commenting on plans to designate the Dyfi Valley a UNESCO-protected
Biosphere, he said that the idea was ‘incredibly important. Initiatives like this can protect
the environment and bring different communities together.’
As part of the workshop, Dr Aponte answered questions on a panel featuring author
George Monbiot, Peter Harper from CAT’s Research and Innovation Department and
Margaret Minhinnick from Sustainability Wales. Mr Monbiot spoke about the need
for a comprehensive government plan of CO2 emissions reductions within a carbon
rationing system. He commended the ‘brilliantly worked-out’ scenario in CAT’s new
report, zerocarbonbritain, saying that massive carbon reductions will only happen
‘when people are pushed into doing what they know they should be doing.’
New postgraduate course – MSc Renewable Energy and the
Built Environment
Following the runaway success of CAT’s first MSc course
in Architecture: Advanced Environmental and Energy
Studies, we launched a unique MSc in Renewable Energy
and the Built Environment in September. Half of the
course modules focus on practical activities, and even the
theoretical modules include practical assessment, making
it the only masters course of its kind in the UK.
Taught by CAT’s Graduate School for the Environment
and validated by the University of East London, MSc
Renewable Energy and the Built Envinronment is designed
for those with a technical graduate background, including
engineers, architects, system specifiers and planners.
Tutors and lecturers include leading experts from the
renewable energy industry, covering a diverse portfolio of
technologies. Students can, if they choose, specialise in a
single technology from a range including solar photovoltaic
(PV), solar thermal, hydro, wind or biomass.
CAT’s existing MSc programme has grown
exponentially from 30 students in 2000 to more than 400
today. The new course will follow the same innovative
structure – students attend for an intensive full week every
month and develop their work at home.
’We believe that very practical training is the most
effective way of training the thousands of renewable
energy experts we will need if we are going to keep our
emissions within a safe level,’ Courses Director Joan
Randle said. ‘I know of several companies that need people
with these skills.’
Cabins for 3 days. They spoke to
CAT representatives about their
research and its similarities to
zerocarbonbritain.
Later in July, the Welsh
Assembly’s Sustainable Futures
Division came to CAT. They
had planned a busy timetable
of meetings with CAT on
various projects. However, once
Development Director Paul Allen
and Lecturer Tim Helweg Larsen
gave them a presentation on
zerocarbonbritain the rest of
the agenda was abandoned to
discuss how Wales can meet
these targets.
From further afield, a group of
six students from Ritsumeikan
and Asia Pacific Universities in
Kyoto and Beppu, cities in Japan,
attended a one-month study
programme at CAT.
A group of students from the
university has come to CAT every
year since 2001. Sara Turnbull,
WISE Business Development
Officer, who facilitated the visit
in 2005, says that around half
of her group of students went
on to find jobs in the field of
sustainability.
New combined heat and
power plant
With the new WISE building
on the way, we are preparing
to meet the increased energy
demand. Contractors are
preparing to build a new building
for a wood-fired combined heat
and power (CHP) plant.
It works by burning wood chips
to produce hot air, which drives
a turbine to produce electricity
(100kWe), and then heats water
(about 250kWt) to go into the
extended district heat system
for space heating and hot water.
The wood chips travel a minimal
4 miles to get to CAT.
‘There are very few examples
of wood-fired CHP in the UK and
it’s very exciting to be testing this
system here,’ said CAT Engineer
David Hood.
Clean Slate n
n
n
Roger’s gardenn
C
ontinuing the story of the rain, so far (17th September)
in 2007, 56 inches recorded rain, but its seemed wetter!
June had 6.5 inches, July 12.5 inches, August 4 inches
and just over 1 inch in September to date. On the 8th of August
we had the first frost: 0.2 degrees Centigrade, it finished off the
fairly useless outdoor cucumbers – a good job really, as they
weren’t up to much. Not the best of years for gardening was
it, but some crops did well, broad beans (from two sowings,
we picked them fourteen times) lettuce, runners, summer
cabbage, kale and broccoli. Indoor carrots, basil and climbing
French bean have been prolific. But celery, celeriac, tomatoes
courgettes, pumpkins, dwarf beans and the winter cabbage
haven’t done a lot. Parsley has been the worst crop this year as
the dreaded carrot fly got it! Because we covered the carrots
with fleece it jumped crop – they are both umbellifera. The mice
got all the first sowings of the chicory, Chinese and Japanese
greens, we had to sow three times to eventually get growing…
Referring to the rainfall graph, the wettest day in the period
we’ve been recording was the 29th of December 1986 with
nearly 6 inches of rain! The wettest month was December 1993
with 20.5 inches. The driest month was a surprise, February
1986 with only 1/5th of an inch of rain! I remember that time
well as my son was in Aberystwyth hospital with a broken leg,
lots of frost night after night with no rain; all the fields looked,
well, burnt out.
With winter beginning to make an appearance, now is the
time to think frost protection for the beets and carrots, they
taste better when dug up fresh. I’ll earth them up with soil,
covering the roots, and when it gets really cold cover them with
fleece and set traps to stop the mice eating the roots. Ideally,
it’s good to cover the ground with a selection of green manures
(special plants that improve the soil), weeds left to grow,
compost (who’s ever got enough?), farm manure (£100 for 15
tons of organic mulch delivered), or black plastic. Probably
the plastic option is the easiest because if you can put it
down now, pegging it or weighting it down so it does not
blow away, it would ensure your ground is free from
annual weeds (but not perennials like couch grass etc.)
in January. If you put some more mulch down around
Christmas it would be ready to cultivate in April 2008 the
start of the growing season around these parts.
Out walking in a wood, clinging to a steep hillside
the other day, I was lucky enough to come across
two goshawk (buzzard?) chicks in a nest
perched on a crag. Returning to the
nest a week or so later only one chick
left, the remaining chick was twice
its original size! I returned one
week later to find it to had gone,
hopefully both had a good start
and made it out there.
A big thank you to our hard
working summer volunteers,
Ikuko, Dominic, Bryn, and
Alana for all their help (bad
luck Alana, she broke her
arm very early on in the
summer).
Oriental Vegetables
Joy Larkom, Frances Lincoln
Publishers, £14.99,
Paperback: 288 pages,
ISBN-10: 0711226121,
ISBN-13: 978-0711226128
In 1985 Joy Larkcom set off to
China to look for vegetables. It
hadn’t escaped her notice how well
flowers and shrubs from the orient
thrived in UK conditions. The logic
went that there must be a similar
array of vegetables which would
perform here just as well.
Since the first edition of this
book appeared in 1991, oriental
vegetables have become much more commonly grown – but with many of
us still referring to them as ‘all those Chinesy leafy things’.
Oriental Vegetables clears up the confusions, not only in helping us
to understand the vast range of ‘leafy things’, but introducing us to
new wonders such as hairy melons, water bamboos and beauty heart
radishes. This is a real gardener’s book with a wealth of information on the
background of the plants, methods of growing and of cooking. The text is
a lovely balance of enthusiastic imagery and detailed practical instruction
– and for quick access, a simple chart contains all the main growing
information. The book is great for experienced gardeners who want to get
their teeth into something new, but also considerate of beginners with useful
pointers on where to start. This new edition, revised with Joy Larkcom’s
latest vegetable wisdom has inspired me to sow more than my usual range
of oriental vegeatbles in the CAT display gardens this autumn.
Chloë Ward
Roger McLennan
Clean Slate
Roger picutred with volunteers, Janet (left) and Helen
n
ask roger
Hi
Delighted to read your info about compost in recent mag’ – had
no idea I could use paper. Please could you explain a bit more?
Have started to shred and add envelopes (they will not take them
for recycling cos of glue). Am I to understand I can put ALL grass
cuttings on as long as I layer them up with shredded paper? And
what about cardboard, cannot shred, how small do I have to cut it
up?
And I live near the sea. If I collect a small bag of seaweed each time
I go to the beach may I just add it to the heap?
And... You say that fibrous stuff helps keeps spaces for oxygen in
the heap so I can add little twiggy bits from trees? As well as weed
stalks?
Thanks a lot for your help and interesting article.
Hilde
“
“
Dear Roger
Your questioner, Chris Champness,
would have less of a problem with
too much cut grass, if he followed the
Henry Doubleday advice:
Not to cut so short… Leave the
cuttings to feed the lawn
instead of taking the
goodness away…
Avoid long
intervals between
mowing, so those
cuttings are
finer.
Christophe
Hall
A friend is someone who thinks you are a good egg, even tho’ you
are a bit cracked!
Yes to your questions with regards to composing shredded and
grass cuttings; a good combination. Cardboard is a bit of work
cutting it up – is worth doing (as small as in practical), you could
crumple rather than cut.
Yes to collecting seaweed and adding to the heap. Branches from
trees probably too thick to include, but by bashing with a hammer,
thick stalks of say kale, could be included. Leaves are best left in
their own heap for leaf mould in 2 years’ time.
Hello I have the following questions:
1. I like the idea of putting fish into one of our water butts. Do you
think it is a good idea? If so, what sort of fish? Where should the
butt be – sun or shade? I read that the fish wouldn’t need food
– is this true? What about the round-leaved weed which is on the
surface of all our butts - should it be cleared if there are fish?
2. Why do you say that we MUST not put the contents of our
Hoovers onto the compost heap? Can I have special permission
to do so, since we use no cleaning products which could cause a
problem? We use none at all apart from eco washing up liquid.
3. The sachets of stuff to be put into the water when we are given
bunches of flowers – what is in them, and can they be put to good
use in the garden or pots?
4. When I grow salads from seed, how can I be sure I am not eating
weeds, as even with new compost, weeds sprout along with the
salad seeds?
Tricia Hobbs
With regards to the question of gold fish in a water butt, why?
It would be difficult to see them but it could work. Yes remove any
duck weed from the surface of the butt.
You could include the contents of your Hoover in the compost heap,
but it maybe a bit, ‘nylon-y’, depending on the type of carpet you
have, and avoid vacuuming up any flea powder or other household
chemicals.
The sachets of stuff from the florists is crystal plant food
powder 95 per cent refined sugar and 5 per cent acidifier and
biocides (kills bacteria) so best avoided.
Weeds will usually have to be weeded out after they germinate
and are big enough to pull so that the seed you sowed can
grow without competition.
Sometimes you could clear a plot then leave it to germinate.
Hoe off whatever appears and then sow your chosen crop;
there wouldn’t be so many weeds to take out that way.
Especially good with slow-to-germinate plants like carrots
parsley, parsnips, etc…
Ask Roger
email [email protected]
or write to: Scott Williams, Clean Slate editor,
Centre for Alternative Technology,
Machynlleth, Powys, SY20 9AZ
Deadline for submissions for Clean Slate 67: January 7, 2008
Clean Slate update
WISE
Recording data for the WISE project has certainly made
me think more about what I buy and where it comes
from. Behind every simple material is an interesting
and complex story. We’re gathering information to
see what the major impacts of our build are and what
the impact will be on the environment. We hope that
comparisons with other materials can be made and to
be able to share any lessons we learn.
Claire Rhydwen
Materials
Take for example a piece of wood. There are many things to consider
and a good place to start is looking into whether the wood being
purchased has come from a sustainably managed forest. The best
standard for checking this is the Forestry Stewardship Council
(FSC)1.For the WISE project, all the timber has been specified to be
FSC certified and so far has mostly come from Scandinavia.
That leads on to the issue of transportation – timber comes from
all over the world, from South America to China, racking up many
thousands of miles, with each mile travelled responsible for emitting
more CO2 (carbon dioxide) into the atmosphere.
But it’s not just where the wood has come from but what kind of
required for the contractors’ cabins and to dry their often sodden
clothing, thanks to the wonderful amount of rainfall we receive in
winter in Wales! On a construction site, planning for contractor’s
needs are certainly a consideration.
Project transport
What may not immediately spring to mind are the CO2 emissions
associated with travel. Not only is there the issue of delivery of
materials, but travel undertaken by the building site staff, visitors,
and that associated with getting all involved parties to the regular
project meetings. We’re recording all this, gathering information
about individual journeys as well as car engine size and fuel type.
Water
With the weather becoming increasingly
unpredictable and extreme weather patterns
becoming a reality, conserving water is something
we’re very aware of. We split our water supply,
from our own reservoir, into filtered and unfiltered
water and measure how much water is being
used in different areas. Filtered water is supplied
for drinking and unfiltered water is supplied
for the toilets and construction site. We’ve put
water-saving ‘Save-a-Flush’2 bags into the site
toilets, that save a litre of water a flush. Assuming
there were eight workers on site every day for
260 days a year, each flushing the loo just once a
day, that’s a saving of over 2,000 litres. It doesn’t
sound like much but when you think of how much
construction is going on and is planned in the UK,
it soon all adds up!
Waste
wood product is being used. Fabricated timber products such as
hardboards and plywoods have been subjected to energy intensive
processes. Plywood timber, for example, has been processed by
cutting, stripping, conditioning using steam or hot water, lathing,
steam or oven drying, gluing, hot pressing, trimming and so on…all
requiring fuel with its associated CO2 emissions to power the
processes.
One has to ask the question ‘is a particular product really worth
the environmental cost or could something with a lower “embodied
energy” be used instead?’
Energy
As well as looking at materials, we’re also recording the amount of
electricity used on site every week. Our electricity is from a green
source so the CO2 emissions associated with this are considerably
lower than they would have been had we been using a non-renewable
energy source. Winter electricity was predictably higher, with heat
Clean Slate
Not only is it the materials we use for construction
that we need to be aware of, but also the waste
generated during the construction process
and at the end of the life of the building. With
landfill sites being said to be full to capacity in as little as 9 years,
accurate ordering and recycling of materials wherever possible is
more important than ever – the DTI (October 2006)3 reported that
92 million tonnes of waste a year are generated by the construction
sector, of which 13 million tonnes are new, unused materials.
We are very aware of this and aim to keep waste to a minimum.
We recycle any materials we can, such as cardboard, paper, wood and
cans, and record the number of skips that have to be sent for landfill.
Walking past a skip the other day I noticed it was brimming full of
plastic. One practice that deserves a closer look is that of emptying
‘dumpy bags’ (those large plastic bags containing things like sand or
aggregate in bulk) by splitting them open, making them suitable only
for landfill rather than re-use….
1. Forestry Stewardship Council – www.fsc.org/en/
2. Save-a-Flush bags from Severn Trent Water – www.stwater.co.uk
3. DTI review of sustainable construction 2006, p. 8
Earth spirituality
Jaise Kuriakose
CAT Engineering
Earth Spirituality
deals with the
interconnectedness
of beings – with each
other and with the
Earth. Whether human
beings acknowledge it
or not, people are all
intimately connected
with trees, birds,
animals and all other
life forms.
E
ach step that we take on Earth is sacred
and is connected to everything else.
However, most human beings seem to
have forgotten that the Earth is the source of all
life, and that we have evolved from her. People
are children of the Earth, and if we treat her
with respect, she will continue to nourish us
physically, psychologically and spiritually.
In the last century or so, a radical and alarming
divide has emerged between people and the
Earth. For the first time in human history,
we have separated ourselves from nature and
confined ourselves within impersonal concrete
cities. We have forgotten where we come from.
People see the Earth, from which we have
evolved, as little more than a mere ‘resource’,
a storehouse of minerals and other raw
materials, inert matter that we need to use in the
furtherance of our physical and material needs.
Chaos theory states that the wing movement
of a butterfly in Peru may later, through an
extremely complex series of unpredictably linked
events, magnify air movements and ultimately
cause a hurricane in Texas.
Chaos theory posits that,
For want of a nail, the shoe was lost
For want of a shoe, the horse was lost
For want of a horse, the rider was lost
For want of a rider, the battle was lost
For want of a battle, the kingdom was lost.
I would add,
For want of a kingdom, the country was lost
For want of a country, planet Earth was lost.
The race that is today’s development model
is being encouraged only by profit-motives. We
see things in fragments, through the eyes of our
present growth paradigm. We have completely
forgotten the notion of inter-connectedness of a
system, things, forms etc. and are driven only by
market trends.
What is needed is a change in our ‘cosmovision’, to see the Earth as our mother, like
indigenous peoples all over the world have
done from the beginning of time. There is no
question that we have deviated from our nature
by exclusively worshipping the technological
creations that so passionately stir and preoccupy
us. Science and technology are not inherently
wrong, but if we humans do not encapsulate
them in the right vision we will use them to
manipulate and exploit the Earth and other
fellow beings.
According to Miriam MacGillis from Genesis
farm, New Jersey, who has attempted to
summarise evolutionary ideas, the universe
came into being 15 billion years ago. First there
was hydrogen, which was around only for about
seven seconds. From the union of hydrogen
atoms came helium. From helium came carbon.
The process of differentiation continued. Our
Earth was formed about five billion years ago.
This is a long, long time ago. For the purpose
of elucidation let us equate 5 billion years to 12
months. Then, of these twelve months of the
Earth’s existence ‘life’ features only in the last
four. From single celled organisms, the process
evolved and differentiated into more and more
complex forms of life. Again, this took a long
time. If the Earth was born 12 months ago, the
modern human came into being only during the
last day, in the last twenty-four hours! We know
hardly anything about these twenty-four hours.
Most of it is buried in a great tribal age of which
no detailed record exists. We have only a little
information on the last five thousand years or so
– the period of the great civilisations. And within
the 24 hours of human existence, the great
civilizations are only 30 minutes old. Our modern
scientific age is only about a couple of minutes
old!
According to Thomas Berry, an authentic, new,
global Earth spirituality lies in the ‘Universe’
story, the emergent story of cosmogenesis,
or the unfolding of cosmic creation leading
to life on earth. The recent rise of religious
fundamentalism has made it difficult for the
three great monotheistic religions to accept a
science-based Earth spirituality. The sense of
God as transcendent and separate from creation
is one of the chief difficulties of the JudeoChristian tradition. Berry would like to recapture
a sense of the immanence of the sacred in
the world. We are at a moment of transition,
according to Berry, in which we need a new
vision to carry us from the end of the ‘Cenozoic’
into the ‘Ecozoic’ Age.
Recently one of my colleagues asked me,
‘Are you saving this planet?’ The first thought
that came to my mind was ‘how can we save
the planet…?’ Or is it that the planet is saving
us? I was reminded of a saying from Fukuoka,
‘Human beings should simply rest on the Earth
however busy they are cultivating it! We are
Clean Slate dreamstime.com
neither the architects of the world or even of our own selves.’ For
him, everything has its proper place in the plan of nature, but humans
are too arrogant to appreciate this. Fukuoka was the oracle of ‘the
one straw revolution’, the method of agriculture known as natural
farming.
In 1854, on another part of our planet, the Native American Chief
Seattle was asked by the American president to sell him some land. It
was a strange question to put to a man to whom the Earth was sacred,
beyond buying or selling. In an inspired response, Chief Seattle
apparently told the president, ‘The Earth is our mother. Whatever
befalls the Earth befalls the sons of the Earth. If men spit upon the
ground, they spit upon themselves. This we know: The Earth does
not belong to man; man belongs to the Earth. This we know. All
things are connected like the blood, which unites one family.’
Tribal people believed in co-operation rather than competition.
Their sense of ‘rights’ was community oriented and not individual.
They believed that a consensual approach to problem solving was
better than a confrontational one. They did not plunder the Earth and
save for the months ahead. They lived each day as it came, collected
food only for the day. If they took a tuber out of the ground they let a
portion remain to regenerate. For them the Earth was mother. There
was no question of speculating on their mother, of buying or selling
her.
All the ancient traditions held planet Earth in great
respect. In Europe, the Celtic festivals were a means of
honouring the rhythms
and changes of the
seasons and the
Clean Slate
bounty given by the Earth. In dance, song, feasting and giving, the
Celts made a pact with the Earth through their festivals to use that
bounty wisely and to give in return for the gifts that they received.
At Samhain, Brigantia, Bealtaine and Lugnassadh, Celts have the
opportunity to make a pact such as our ancestors made with Mother
Earth. We then have the chance to honour the gifts that we receive
by giving thanks and by giving in return. We have the chance to
celebrate the turning cycles of time, and to find our true spirit once
again in the belief that all things that are here must pass and that
all things that have passed will return. The pre-Christian world of
the Celts was animate and soulful. The land was the Great Goddess,
whose breasts flowed with the rivers that fertilised the Earth.
According to the current Prince of Wales: ‘Religion and science
have become separated, and science has attempted to separate
the natural world from God, with the result that it has fragmented
the cosmos and placed the sacred into a separate, and secondary,
compartment of our understanding, divorced from the practical day
to day world of man.
‘We are only now beginning to understand the disastrous results of
this outlook. The Western world has lost a sense of the wholeness of
our environment, and of our inalienable responsibility for the whole
of creation.
‘This has led to an increasing failure to appreciate or understand
tradition and the wisdom of our forebears
accumulated over the
centuries.
regarding a tree as a piece of wood for individual consumption or as
a living organism. Why do humans think that nature is meant simply
to satisfy human needs? If we co-exist with nature, we cannot just see
it as a piece of wood or a stone. The tree and the person become two
species experiencing life on this planet together. We have diverted life
and established hierarchic notions of higher and lower beings. That
is one of the reasons for the suffering on our planet. So, co-existing
is not about cultivating organic food, but about cultivating organic
people. It is the extension of our relationship and experience of
living beyond humans. One has to broaden the conventional human
perspective on life, expanding our experience of existence.
Above all, we will have to change our perception of ‘progress’
and reconsider paradigms of knowledge, alongside rethinking our
day-to-day activities and life styles. A touch of humility is called for.
We may have to concede that we still cannot answer fundamental
questions about where we come from or where we are going. We only
have to look into the clear night sky to see our own smallness and
acknowledge that planet Earth is a mere speck in the universe, which
has billions of other objects we know next to nothing about. Talking
of humility and pluralism, the story goes that the Buddha clasped a
handful of fallen leaves and asked his favourite disciple Ananda what
he saw before him. ‘A fistful of leaves,’ said Ananda. ‘But are these, all
the leaves in the world?’ asked the Buddha. ‘No, there are millions of
other leaves,’ replied Ananda. ‘So is my teaching,’ said the Buddha, ‘a
handful of leaves among millions of others.’
Forget not that the earth delights to feel your bare feet,
And the wind longs to play with your hair! Khalil Gilbran
here’s enough on this planet for everyone’s needs but not for
T
everyone’s greed. Mahatma Gandhi CS
References:
• Siddhartha, Earth Spirituality – A New Eco-Social Paradigm,
Butterfly Futures, Pipal Tree
• HRH The Prince of Wales, speech entitled ‘A Sense of The Sacred
in the modern World’ at the Investcorp Dinner, London, 10th July,
1996
• The Spirituality of the Earth,
Thomas Berry, Orbis Books, New York, 1990
• http://www.heartoscotland.com
• ‘Spirituality and Sustainability’, Dara Molloy,
Aisling Magazine, issue 25, Bealtaine, 1999
• Chandra Shekhar Mohanty, ‘Indian Village: An Ecological
Perspective’ – International Society for Environmental
Botanists – India Newsletter, 1995
• Chief Seattle’s 1854 Oration, http://en.wikipedia.org
• http://www.fukuokafarmingol.info/index.html
• Universe Story, Brian Swimme and Thomas Berry,
Harper Collins, San Francisco, 1994
• Introduction to Chaotic Dynamical Systems,
Robert L Devaney, Westview Press, 2003
dreamstime.com
‘Our environment has suffered beyond our worst nightmares,
in part because of a one-sided approach to economic development
which, until recently, failed to take account of the inter-relatedness of
creation, and the importance of finding a sustainable balance working
within the grain of nature and understanding the necessity of limits.
‘This, for example, is why protection of our environment is such a
relatively recent concern; and why organic and sustainable farming
are so important if we are to use the land in a way which will
safeguard its ability to nourish future generations.’
In India, Mahatma Gandhi dreamed of a village where all the
things needed by the villagers would be manufactured from locally
available resources. This village would therefore be self-sufficient
and sustainable. In a typical Indian village nearly 2,364 tons of rural
wastes, in the form of crop residues, animal manure and human
excreta, are produced annually by a population of 510. About 77 per
cent of the waste generated in the village would be used as domestic
fuel, animal fodder and organic fertiliser for crop production.
The rest (23 per cent) would be left out in open fields for natural
decomposition. The energy balance sheet of such a typical village
shows that the present consumption of biomass resources is 50
per cent less than that actually required for various domestic and
agricultural applications. Anaerobic digestion of animal manure and
human excreta produced in a village could yield 82 per cent of the
domestic energy required, besides enriching the waste by 3-4 times
as compared to conventional storage on the ground. If the traditional
mud chulha (stove) were replaced by an improved chulha, each
family unit might also reduce its annual consumption of wood fuel.
The use of non-renewable energy in Indian villages is very low.
In agriculture it is minimal, as subsistence farming is mostly based
on human labour and animal power rather than oil and electricity.
Cultivation in large areas is done by hoe and animal draught. The use
of tractors for tilling the land is also common in some areas. Ground
water is lifted variously by human power and by animal power. Tube
wells and water pumps are also becoming popular in many areas.
Cooking and lighting use local energy sources such as biogas, solar
energy, firewood, and dung. Part of some villages’ income comes
from communal energy farming with Eucalyptus and different
species of Euphorbia (a succulent) and other energy crops, which
enable them to be, by a small margin, a net exporter of energy. Even
the tools and utensils used in villages are produced nearby in small
regional centres using small quantities of non-renewable energy.
Careful research can improve the energy efficiency in such villages
and take out out all the non-renewable energy sources to enable the
village to become 100 per cent energy secure. The above scenario
can be extended to other parts of the globe by incorporating their
environmental and social conditions.
However, care must be taken to see that this process is not just
about growing flowers and trees without chemicals and with zero
carbon emissions. It is about blooming together! There’s
a big difference between
Clean Slate climate change and
gardening
Grace Crabb
CAT Biology
In the UK, climate
change has already
begun to create
drier summers,
wetter winters and
more unpredictable
weather patterns.
10 Clean Slate
U
npredictable weather systems provide
many new concerns for the growers and
gardeners in Britain who have long relied
on traditional planting, not only for beautification
of the garden but for economic survival. Here in
the CAT Biology Department, as a volunteer fresh
from arid Spain, I was asked to create a dry garden
demonstrating the range of plants more suitable
for the arid conditions brought on by global
warming.
My background is in biodiversity conservation,
so I felt it important to include a range of native
plants. I discovered that there are several
companies supplying native plugs ready to plant.
Research into the more drought tolerant natives
was relatively easy using various websites such as
the Plants for a Future database, Garden Organic
and the catalogue from British Wild Flower Plants.
Other plants I chose at random. At this point I
must confess that although familiar with trees
and native species, gardening with cultivars was
very new to me. It became apparent, however, by
referring to seminal books such as Beth Chatto’s
The Dry Garden, and utilising some invaluable
advice from our local nursery in Machynlleth,
that the range of drought tolerant plants is truly
prodigious. Many of the common cultivars that
we use in our gardens in the UK are derived from
exotic drought tolerant species from all over the
world.
The Dry Garden at CAT is now established. The
evening primrose and white campion, speedwell
and fragrant agrimony are all gracing the garden
and attracting native insects. The other plants
are flourishing equally well, particularly the
Miscanthus, Lithodora, golden sage, Choisya
and Helichrysum. The Diascia has exploded with
pretty pink flowers and has begun to engulf the
path. And the lemon verbena…the scent is truly
heavenly. This plant will always be a favourite of
mine. Even the olive tree is doing well.
Sadly, I feel a little bit of a fraud. This dry garden
is particularly special. It is under cover, situated
in a rather attractive geodesic glass dome, which
protects it from external weather effects. Wales
is not expected to dry up under the less extreme
IPCC (Intergovernmental Panel on Climate
Change) projections. It is in fact expected to suffer
other water problems, particularly flooding. Whilst
the south of Britain is expected to become drier, it
too will be likely to succumb to heavier downpours
in winter along with little rain in summer. However,
the north and west of the country is expected not
to suffer this problem, due to the complexities of
the Atlantic weather cycles. This was particularly
apparent to me as I took shelter from this
summer’s constant rain in my dry garden at CAT.
Perhaps the media is dangerously optimistic in
the face of climate change and, in fact, predictions
for the changes in our weather do not simply
mean popping in a few Mediterranean plants and
forgetting about it.
Turning to the technicalities of drought
resistance, if plants get too dry, the stomata
(pores) close up, decreasing evaporation from the
leaves and preserving water. This in turn reduces
the photosynthetic ability of the plant as it can’t
absorb as much CO2. In the slightly longer term
(days, weeks, months) the plant will shed its older
leaves and become more compact with smaller,
thicker leaves. The root systems may become
larger at the expense of the size of the plant
above ground. Water stress in annuals results in
a speeding up of flowering so that the seeds are
set before the plant dies. The flowering season
is therefore shorter. In the much longer term,
plants evolve to suit a drier environment; hairiness
reflects light and reduces evaporation. Waxiness
also reflects light and the toughness of the leaf
surface directly prevents evaporation. These
adaptations result in the silvery or grey foliage
we see in many of our common cultivars. For
the CAT garden I chose a delightful wormwood,
’Powis Castle’, which displays these drought
tolerant characteristics. Leaves may become
thinner with a smaller surface area (e.g. rosemary)
to prevent evaporation, and stomata numbers
fall, or eventually totally disappear. It is easy to
incorporate these plants from around the world
into our gardens.
Some of our natives have a few of these droughtresistant characteristics, too, for example some
coastal species subject to desiccating winds. Some
of the chalk grassland species familiar to me from
my volunteer days at the White Cliffs Countryside
Project in Dover have adapted to harsher
conditions where soil is thin and desiccation can
occur. But these are only a few. The vast number
of native plants simply have not adapted to what
the weather has in store, even under low emissions
scenarios. Plants have never in the history of the
planet been subjected to such rapid climate change
as in this Anthropocene1 era and they cannot
be expected to evolve quickly enough to cope.
Perhaps it is time, rather than replacing our natives and broadleaves with
funky exotics, to attempt to plant more of these threatened species alongside
our cultivars – to increase their range and give them a greater chance
of survival in the unpredictable future. It is not only the plants that are
threatened, but also the chain of creatures that rely upon them to survive.
It is certainly worth selecting less thirsty plants for the garden, but using
drought tolerant plants in some areas of the UK will be difficult. When the
summer rains well and truly set in this year, I was relieved that the dry
garden here at CAT was under a glass dome. With heavier bursts of rain
predicted for much of the UK it seems that the answer to tricky weather
could lie in what we do for our soil structure. On light soils, higher levels of
winter precipitation will be greatly appreciated, recharging the water table
and reviving the plants. However, the danger from these downpours is that
heavier soils will become waterlogged. This deprives plant roots of oxygen
and kills the whole thing. Some plants will cope well in short periods of
waterlogging as they are inactive in winter. Others are utterly intolerant and
will die quickly. To add to the problem, in warmer winters the root activity
of plants will increase, meaning a decreased tolerance to waterlogging. It is
very important then to improve drainage in the soil. Sand and gravel can be
added to heavy soils.
In some areas the soils will be poor, and heavy downpours after very dry
summers may wash away the top soil leading to desertification. For both
scenarios adding humble compost will make an astonishing difference. Not
only does home composting reduce your personal carbon count significantly,
it also allows you to put back the nutrients that give soil structure and make
it a living, breathing substance resilient to drought and flood. Compost
creates a free draining medium in winter and a spongy, water retentive one
in summer.
It is essential to add compost to stressed soils, and in hot months
mulching can make a massive difference to moisture retention. In Spain
I would bucket feed my trees, watering them very irregularly, but heavily,
so that water would trickle deep into the soil, allowing for greater root
growth. Watering little and often causes the roots to stay in their unreliable
surface comfort zone. I would then heavily mulch the catchment I had dug
with straw. Any moisture would then be trapped under the mulch and be
retained. Bark chips, gravel, leaf mould and other mulches can also be used.
Mulching also prevents the weeds from competing with your plant for water
and nutrients.
Plants display complex responses to increased CO2 and higher
temperatures. In some instances this can actually be beneficial for plants in a
climate such as that of the UK. From an agricultural perspective, increasing
the availability of heat and CO2 extends the growing season, increases
yields for some species and allows for a wider range of plants to be grown.
A doubling of CO2 may increase plant growth by 40-50 per cent2. Pretty
much all plants like it, but coupled with temperature increase, perhaps
only crops harvested at an early stage of development, such as carrots, will
respond well to increasing CO2. Carrots will certainly be one crop of choice
in 2080. A one per cent increase in soil temperature would induce a 34 per
cent increased yield. In fact, root crops will probably fare best. Onions and
cauliflowers show a negative effect with increasing temperatures. Increased
temperatures will accelerate growth and hence bring about a shorter period
of bulb growth. Higher levels of CO2 are not enough to counteract this
effect and a 1 degree increase in temperature will decrease bulb yield by
3.5-15 per cent2. Potatoes are very happy in our current climate. Increased
temperatures would again bring forward the senescence and death of foliage
and therefore end growth. There would also be more days with reduced
growth at higher temperatures, resulting in smaller tubers. But in the case
of the potato, increased CO2 levels could compensate for this, and we might
even expect small increases in yields. Earlier planting will also allow for
greater yields. Every plant is different. Some plants may relish the changes
and be in season all year round, whilst others will not survive so well in
the higher temperatures. Growers that rely on the onset of frost, such as
rhubarb growers, have already reported problems in their growing sheds.
Plants have evolved complex relationships with their environments,
of which we understand very little. Many seeds need frost in order for
Clean Slate 11
stratification to occur: each seed species requires a different dormant
period where it is exposed to chilling temperatures, triggering
growth. Wood chilling time has already decreased to the point of
inadequacy for some species, such as the blackcurrant, which has
suffered poor cropping after recent mild winters. The beech is
expected to be one of the first tree victims of climate change in the
UK. Beech (Fagus sylvatica) needs a long chilling period, secretly
and slowly forming flower buds under its winter bark. Beech also
has one of the latest leaf emergence times of any of our natives.
It is expected that with less accumulated chilling, the leaves will
emerge even later, perhaps with deformities or failure to flower.
Hawthorn (Crataegus monogyna) on the other hand, has a small
chilling requirement and will therefore emerge earlier. A common
worry, as gardeners watch the early emergence of their bulbs and
tender shoots, is that sensitive growth will be highly susceptible
to unanticipated frost damage. However, one projection is that in a
warmer world with early emergence comes less incidence of frost in
general, negating the impact of the killer late frost. It is more likely
that frost damage will occur in the autumn, due to clear skies and
delayed dormancy.
The biggest problem is that no one truly knows what to expect.
Will the global breadbasket move to Canada and the Arctic, as
Europe becomes simply too hot? Perhaps it will only be desert
dwelling plants that survive in the south of England. With the
increasingly ferocious Atlantic storms predicted no longer drifting
over the drier Mediterranean but instead tracking over northern
Europe3, and with risks of flooding in Scotland and North Wales,
perhaps we will have stopped gardening all together. This projection
may seem extreme but if current emissions scenarios, researched
12 Clean Slate
heavily by the IPCC, are anything to go by, we can expect some big
changes in our habitat in the next century. It is essential that we
respond to increased temperatures, but that we also understand the
underlying processes that are making this happen, and try to prevent
weather systems from altering to the point where crops suffer and
need to be moved to areas where there is more water. The warming
of the planet and the increasing levels of CO2 must be addressed in
our day-to-day activities and lifestyles, so that we can keep our native
plants. In this warmer world, we can certainly care for our soils
better and choose less thirsty plants, but it is important to keep in
mind why we find ourselves having to adapt in the first place. CS
1. The term Anthropocene is used by some scientists to describe
the most recent period in the Earth’s history, starting in the 18th
century when the activities of the human race first began to have
a significant global impact on the Earth’s climate and ecosystems.
The term was coined in 2000 by the Nobel Prize winning scientist
Paul Crutzen, who regards the influence of mankind on the
Earth in recent centuries as so significant as to constitute a new
geological era.
2. Gardening in a Global Greenhouse, Richard Bisgrove and Prof. Paul
Hadley, Nov 2002, UK Climate Impacts Programme publication.
A scoping study looking at the impacts of climate change on UK
gardens (both domestic and heritage gardens) and on the industry
serving the gardening community.
3. 6 degrees: Our Future on a Hotter Planet, Mark Lynas, March 2007,
4th Estate, Harper Collins. A thorough examination into the effects
of global warming assessed degree by degree.
An absolute must-read.
PRACTICAL solutions
compiled by Sophie Holdstock and Tatsuro Shigetomi
myhab – leave the abandoned tent behind
More than 20,000 tents were left in the muddy fields of some British festivals this summer. Tents are
becoming cheaper, encouraging a casual attitude towards leaving them after a weekend of mud and
mayhem. The abandoned tent is just another example of the mounting waste left by the wayside of our
consumption-driven society.
On the bright side of the landfill, James Dunlop, a product design student from University of the West
of England has developed ‘myhab’, a creative solution made from recycled cardboard.
When James spoke to waste managers at the festivals, they said that their biggest problem was the
number of tents discarded on site. Completely made out of recycled materials and powered by a solar
panel, myhab can be ordered on the Internet and put up and taken down for you. myhab will also allow
you to relax on the train or coach to the festival sites reducing the number of cars travelling to the
event. You can even forget dragging your heavy tent across festivals.
Mr Dunlop said that ‘the design, which accommodates two people, could have other uses, such as for
disaster relief and housing for the London Olympics.’
With a full launch of myhab planned for summer 2008, the abandoned tent could become a thing of the
past.
www.myhab.com; 020 7397 4912
How to Combat Climate Change with your
Community: ‘Transition Towns’
Climate change and oil depletion are such huge
issues that the sheer scale of the problems can
feel disempowering. Instead of waiting to see
if there will be an alternative when the oil runs
out, communities involved in the Transition
Towns movement are busy taking matters into
their own hands. Working together across the
UK, Transition Towns are planning imaginative
initiatives for a more sustainable, fulfilling,
equitable and low carbon lifestyle in a bid to
escape their dependency on oil.
The founder of Transition Towns, Rob Hopkins,
comes from a permaculture background, so is
used to giving people the tools to make their
lives more sustainable. ‘Since I found out about
peak oil, I have become fascinated by how we
apply these principles to whole towns, whole
settlements, and in particular, how we design
this transition in such a way that people will
embrace it as a common journey, as something
positive,’ he said. Many Transition Towns ideals
follow on from permaculture principles – growing
your own vegetables, developing allotments,
community compost schemes and shortening
food supply chains.
It is common to hear the phrase ‘oil addiction’ in
relation to our dependence on fossil fuels, and
the Transition Towns movement takes this a step
further with its own 12-step programme. The first
step starts with the creation of a steering group,
while the final stage is the implementation of
an ‘energy descent’ plan. The approach enables
communities to visualise their town’s potential in
20 years’ time, and plan the stages towards their
goal.
Totnes in Devon was the first Transition Town
in the UK. The project has been so successful
that the town has developed its own currency,
encouraging a local economy supporting local
produce, goods and services.
At a meeting of Lampeter’s Transition Towns
group, the ideas considered ranged from a ban
on advertising that encourages consumption
to turning the local supermarket site into a
giant allotment. Other ideas included installing
a community wind turbine and skill swapping
workshops.
One of the aims of the 12-step programme
is to give the movement complete flexibility.
Becoming part of the Transition Towns network
requires no joining fee or membership – it is
simply a gathering of likeminded towns and cities
from Bristol to Brixton to Falmouth, sharing
creative ideas for an energy descent plan. If you
are interested in Transition Towns, the network
can assist you in starting the project, building a
website, and helping organise your first event.
www.transitiontowns.org
Beat the Plane… Travel by Train
Open the newspapers or surf the net and the
pages are littered with adverts for cheap flights
luring you and your friends for a quick break
in Europe with the prospect of cheap beer,
cigarettes and accommodation only a quick
hop and a skip from Stansted or Liverpool or
Manchester...
Air travel is the fastest growing contributor to
climate change. According to the Tyndall Centre,
based on government projections of UK aviation
growth to 2050, greenhouse gas emissions from
planes alone will exceed the government’s 60 per
cent CO2 reduction target, and that’s before any
other emissions are counted.
The temptation to fly can be tough to avoid,
especially as it seems to be part of everyday
life, but a viable alternative is simple and easily
available. www.Seat61.com is a useful website
when organising train travel throughout Europe
and the UK. This not for profit website aims to
give travellers the option of an alternative to
the airport. The benefits are more than purely
environmental – you can take more than one
piece of hand luggage and enjoy the beautiful
scenery on the way. Packed with information
from travelling with bikes to timetables and
cheap tickets, the website and telephone service
is a hidden gem, organising your low-carbon
travel to nearby and far-flung destinations. It even
includes timetables within the UK.
Another option for low-cost low-carbon travel in
the UK is the MegaBus. A great deal, with oneway travel costing only £5.00, MegaBus is the
cheapest option for inter city travel for those that
have missed those early bird train tickets.
http://www.seat61.com/UKtravel.htm
www.megabus.com
Stitch and Bitch
A stitch in time saves exploited labour, the use
of harmful chemicals, transport and production
waste, energy and other impacts on the
environment. Around 20 per cent of the world’s
most hazardous insecticides and pesticides are
used in cotton production.
A practical solution to the impact of clothing is
to organise a Stitch and Bitch session. Take time
out from the clothes shopping and sit down with
some friends to fix up your old favourites. Or
recycle materials to make ‘one-of-a-kinds’ that are
impossible to find on the high street.
You could organise your own group, or perhaps
there is already a group meeting in your area.
Details of networks can be found at
http://www.stitchnbitch.co.uk/
Food Carbon Footprint Calculator
Food is estimated to be responsible for around
20 per cent of the UK’s CO2 emissions. CAT has
long promoted the importance of a local, organic,
low-meat diet. Now a tool exists for you to see
how your food habits measure up – an online
calculator of CO2 emissions from the production,
packaging and transport of food. It gives you a
personal Food Carbon Footprint estimate based
on your answers to a series of questions, created
using data from Defra.
www.foodcarbon.co.uk
Clean Slate 13
illegal vegetables and how to
grow themTim Hogg
Chloë Ward
CAT Gardens
I grew some very
pretty beans this year.
The plants had cream
and white flowers and
seemed to leap up
their hazel stakes. I
ate the tender green
beans in salads and stir
fries – but I’m leaving
plenty to dry on the
plant. Then I’ll collect
the dry pods, shell the
beans and store them
for sowing next year.
14 Clean Slate
D
o you like the sound of this bean?
Want to grow it too? I could sell you
some seed for a quid. Bargain? Sadly,
though, the law does not permit it. It is illegal
to sell my bean seed. Why? Do the seeds yield
an illegal drug? Is it an invasive species likely to
wreak havoc on our natural ecosystems? Does
the plant contain some kind of hazardous toxin?
No – it’s just a sweet, innocent, harmless bean, a
Climbing French bean with the botanical name
of Phaseolus vulgaris. But French beans come
with cultivar names too, like ‘Neckar Queen’
and ‘Blauhilde’ and mine hasn’t got one. It’s got
no birth certificate. This is the problem. Ever
since the passing of the Seed (National List of
Varieties) Act 1973, a vegetable seed can only
be sold if it is on a special list. To get on the list
it has to pass a DUS test. It must be Distinct
(different from all other varieties), Uniform (all
the plants grown from a pack of seed must be the
same) and it must be Stable (the plants should
not change from generation to generation). The
vegetable seeds for sale today are all on the list.
The ones your neighbour gives you may not be.
What all this means is that there are fewer
vegetable varieties on sale than there used to be.
Old varieties are in danger of becoming extinct.
Many seeds for sale are commercial varieties
bred for characteristics needed by supermarkets
– such as tough skins to survive transport
– rather than sweet taste or nutritional content.
Hybrid (F1) varieties are especially lucrative for
the seed companies as they will not breed true
– with F1 varieties you have no choice but to buy
new seed each year.
It is hard for small seed companies to survive
when producing relatively small quantities of
seed for the domestic gardener. Many have
gone out of business since the 1960s, often
having been bought out by larger companies.
Hence many people today have a very limited
idea of what vegetables look like. Tomatoes are
uniformly red, beans are green, and carrots are
orange. Not so in a heritage vegetable garden,
where purple beans climb above stripy tomatoes
next to yellow carrots. Vegetables are wondrous
in their diversity of colours, shapes and sizes,
as well as characteristics we cannot see, like
resistance to pests and diseases.
Having a wide vegetable diversity is fun and
gives beauty to our gardens – but it’s also crucial
for our future. Vegetables are our food. We need
them. We need to be able to grow them whatever
the future throws at us. The more diversity in
our vegetables, the easier it is to find ones that
will thrive in our own local conditions as well
as cope in a future with an unstable climate and
unpredictable pest and disease patterns.
The loss of many of our vegetable varieties
hasn’t gone unnoticed. In 1975 there was enough
Industrialised Crop Farming!
foresight in the Henry Doubleday Research Association (now
Garden Organic) to set up the Heritage Seed Library (HSL).
Gardeners could no longer ‘buy’ the seeds of their favourite
vegetables – but maybe they could just borrow them? Surely that
couldn’t be illegal? So the HSL gathered all the non-listed seed
they could find and started lending it out. Members are sent
their choice of varieties to grow each year and some are also
‘Seed Guardians’ who are trusted to save and return the seed, so
replenishing stocks.
The seed saving movement is not just about preserving
old varieties, however. If we get new seed each year, grow it,
eat it, and then go back for more it means vegetables are no
longer evolving in our gardens. They become stuck in time.
In contrast, every time we save our own seed the plants are
evolving to perform better in our gardens. Even though we
may be controlling them to keep the variety ‘pure’ there will
still be mutations and some cross pollination to introduce new
characteristics. These will be selected for or against. The variety
will continue to perform better for us as we select the most
productive, tasty or beautiful plants. If you save your own seed
you will not only be preserving old varieties, but creating new
ones for the future.
Seed saving has become a strong movement in many places
throughout the world, and seed swapping events are increasingly
popular. At the 2007 ‘Seedy Sunday’ in Machynlleth, Syd
Melbourne gave some of his bean seeds to the Heritage Seed
Library. Syd had been given a handful of the beans in the 1970s
by a friend who knew that the variety was no longer going to be
sold. He has been growing and saving them ever since.
So this is how I got to grow my very pretty beans – Syd’s
bean, which he has named the ‘Melbourne Mini’. While growing
them in the CAT display gardens we are recording their
characteristics. Each stage of growth is monitored according
to the ‘characterisation’ forms provided by the HSL. This could
help us find out a lot more about it. It could be an old variety
lost to the seed companies in the 1970s; it could be a variety still
commercially available, or one held in the seed library. However,
over the time Syd has been saving his seed it will have adapted
to his particular garden conditions. It might perhaps be the only
remaining seed of an old variety or his own strain of another
variety. Either way, with the help of the Heritage Seed Library we
will be saving the ‘Melbourne Mini’ for future generations.
How to save seed
We are used to seeing vegetables flower and set seed – peas
and beans are obvious examples, as well as plants that fruit e.g.
tomatoes. Others we eat before the plant seeds. One of the many
Although the question of genetic modification has been a
controversial issue for some time, shops are now selling products
that contain or have used genetically modified material in their
production. That the biotech companies have managed this despite
strong opposition from the public, or at worst indifference, is a severe
blow to the concept of consumer choice. What reasons are they
giving for the ‘need’ for GM crops that outweighs the dangers of their
growth? What are these dangers? How does the patenting of crops
and ‘suicide seeds’ affect farmers and whom does the law protect?
Bio-tech companies design ‘improved’ varieties of plants that,
they claim, will produce higher yields, help solve world hunger,
compensate for dietary deficiencies and deal with population growth.
They spend a lot of time and money designing such varieties and
can then patent the seeds as their intellectual property. To make
sure farmers buy from them year on year and do not save seeds
from a previous harvest, thus stealing the technology, the designers
embed self poisoning genes into the gene structure to prevent illegal
copying in much the same way as IT software does. This is known as
Terminator Technology or ‘suicide seeds’.
Our ancestral farmers have been saving seeds and selecting a varied
set of beneficial characteristics for over ten thousand years. Not only
will this wide set of varieties be lost, many of which are specifically
suitable for their local regions, but the skills will be lost, and the
independence of farmers will be lost.
The consequent dependence on agribusiness carries a catastrophic
risk; should seed production be interrupted or lost, farmers would
be left with nothing to plant. Pollen is an airborne transmitter of
information; releasing unnatural and destructive genes into the
biological kingdom has unknown consequences and could potentially
jeopardise food production and plant life. Should the killer gene be
transmitted to related species of plants this could have a harmful
effect on all crops and wildlife.
Terminator technology will result in crop uniformity leading to
increased vulnerability to pests and diseases with no other crops to
grow as backup. Use of crops that are resistant to pesticides will lead
to an imbalance in the food chain. For example, birds that eat insects
will be threatened because the plants the insects eat will have gone.
The cost of seeds will be expensive to poor farmers and it is unlikely
any benefit from any increased yield will outweigh the price of the
seeds and should a crop fail farmers will need to take out loans.
As well as the risks to the environment and our food production
there are also the legal risks and consequences imposed on farmers.
There is no legislation that requires biotech companies to pay
compensation or clear up any damage caused by their crops. Where
genetic material has polluted non-GM crops, the polluters have not
paid damages.
North American farmer Tom Wiley landed a contract to supply Japan
with non-GM soya. On delivery it was discovered that the beans were
contaminated up to 1.37 per cent with GM material.
The contract was cancelled at a loss of up to $10,000 to Mr Wiley
without compensation. Worse than this is the case of Percy
Schmeiser, a Canadian farmer who had been using his own seeds
for the past fifty years. His canola seed was genetically polluted with
Monsanto’s GM canola through wind and pollination. Instead of
Percy being paid compensation in accordance with the polluter pays
principle, the courts fined Percy on the basis of Monsanto’s IPR case
which argued that since the genes were Monsanto’s property their
being found in Percy’s field made him a thief, irrespective of how
they came to be there.
http://www.soilassociation.org/gm
http://www.genewatch.org/
Chis Moreton
Clean Slate 15
advantages of being a seed saver is that you get to see the beautiful
flowers of biennial vegetables too – pom-pom type onion heads,
umbrella shaped carrot and parsnip florets, bright yellow brassica
flowers, lettuce stalks shooting up 4 foot high.
Some vegetables (called inbreeders) e.g. French beans, nearly
always self-pollinate. This means that it doesn’t matter if you have
a similar plant growing nearby – they won’t cross. Others are more
promiscuous. These need to be isolated from similar plants. Some
vegetables (called outbreeders) e.g. sweetcorn need to crosspollinate, but within their own variety. With these it is important to
grow a large number of plants to prevent ‘inbreeding depression’.
Seed collection techniques vary – large dry seeds like beans and
peas can be shelled by hand. For small dry seeds there are methods
such as winnowing, to remove the seeds from the chaff. ‘Wet’ seeds
such as tomatoes need to be cleaned thoroughly before storage.
However, some vegetables are really easy to save seed from, and
once you start it can become addictive. CS
Further information
For advice on how to save seed and to join the Heritage Seed
Library go to www.gardenorganic.org.uk/hsl
Books
Heritage Vegetables – the gardener’s guide to cultivating diversity,
Sue Stickland, Gaia Books, ISBN-13: 978-1856750332
Breed your own vegetable varieties – the gardener’s and farmers’
guide to plant breeding and seed saving, Carol Deppe,
Chelsea Green Publishing, ISBN-13: 978-1890132729
Additional material from Chris Moreton and Mel Harvey
16 Clean Slate
The search for Welsh vegetable varieties
Dyfi Valley Seed Savers are based in Machynlleth. The group
have energetic annual seed and seedling swaps and organise
other gardening events throughout the year. This year the Seed
Savers have launched a search for traditional and adapted Welsh
vegetables, in order to bring together a collection of varieties that
grow well in the wet and rugged conditions here. The aim is to
chronicle their characteristics and history, and ensure that the
diversity and heritage of Welsh vegetable varieties can adapt to
changing conditions.
If you save and grow your own vegetable seeds in Wales, we would
love to hear from you. They could be vegetable varieties that have
grown well in the region for generations, the product of a backgarden plant-breeder, or a traditional variety that carries a story in
its name. Please get in touch with us at the address below with any
information about Welsh vegetables or for more information about
the seed search.
Chloë Ward
Dyfi Valley Seedsavers,
Ecodyfi,
52 Heol Maengwyn,
Machynlleth, SY20 8DT
Phone: 01654 700 288
email: [email protected]
Website: www.dyfivalleyseedsavers.co.uk
zerocarbonbritain – doing it yourself…
Matthew Slack
The last issue of Clean Slate introduced zerocarbonbritain, CAT’s radical
new energy strategy. This ambitious programme shows how the UK
might eliminate its carbon dioxide emissions in the space of twenty
years. The report describes a system of ‘Tradeable Energy Quotas’
(TEQs) at a national level, within the international framework of
‘Contraction and Convergence’ (C&C). Britain accepts the constraint
of an equitable share of a global carbon budget from C&C, and
distributes this fairly to every citizen through TEQs.You can read the
full description of these mechanisms both in the full report, and on the
TEQs and C&C websites. References are given at the end of this article.
The annual carbon allowance in the starting year is equal to current
usage, so that implementing the policy does not cause a sudden
reduction in the availability of energy.Year by year the budget is reduced
by 5 per cent (simple, not compound) so that after 20 years it is
reduced to zero. The tools used to achieve this are ‘Powerdown’ – using
less energy to start with – and ‘Powerup’ – the introduction of zero
carbon energy sources to supply the remaining, greatly reduced demand.
In the early years of the programme, ‘Powerdown’ will predominate.
We already know enough to halve energy use in many areas.
Widespread implementation of this existing knowledge buys time in
which to roll out the major renewable energy generation technologies
that drive ‘Powerup’.
Simple, then. Except that to get started we need international
agreement to adopt C&C and national legislation to implement
TEQs. With the best will in the world, that will take some years. The
zerocarbonbritain programme is only twenty years long: we can’t afford
to waste several of them waiting to get started.
The point of this article is to invite you to join our practical, voluntary
implementation of the zerocarbonbritain vision. We want to collect
data from real households to show that the starting level of carbon
allowance is realistic, and that the rate of emissions reduction
demanded is achievable. There is no more powerful argument when
trying to influence cautious policy makers than a real-life group of
people actually living out the plan.
The arguments against the zerocarbonbritain approach fall into two
main types: first, unease at the mechanism and resistance to what
effectively amounts to carbon rationing, and secondly scepticism about
the feasibility of achieving the levels of emissions reduction that it
calls for. We are focusing on the second point because, as mentioned
previously, the knowledge to halve emissions already exists: we can get
to year 10 without the need for any revolutionary advances. It is just a
matter of implementing what we already know.
If you would like to join in, then all you need to do is email us at
[email protected]. We will send you the details of the data
we would like to collect., and a spreadsheet to make the task
straightforward.
Other initiatives are also underway. The Royal Society is exploring
carbon trading in practical, public sessions throughout the country.
There is also a network of local groups called CRAGs: ‘Carbon
Reduction Action Groups’, in which some CAT members are already
active. The main difference between our approach and that of the
CRAGs is the method of setting the carbon reduction parameters.
Each CRAG chooses its own parameters; we want to work within the
framework of zerocarbonbritain. To begin with there is actually little
difference between zerocarbonbritain and the average values used by
the CRAGs. Do feel free to join in both approaches: if there is a local
CRAG then join it; if not consider starting one. Contact details for the
RSA scheme and CRAGs are given below.
So, let’s look at the numbers. The TEQs system introduces the idea of
an annual personal carbon allowance. But how big is it? What does it
cover? How does it fit a typical household?
Under the TEQs system, the national carbon budget is distributed in
two ways. Part of it is given freely to everyone who lives in Britain,
with equal shares per head. The remainder has to cover the needs of
business, industry and government. They don’t get any free allowances
– they have to buy the right to emit CO2, and pass on the cost of this in
the price of their goods and services.
The freely allocated part covers our direct fossil fuel purchases, and
so its size is determined by the proportion of total UK energy use
currently sold that way. This amounts to 40 per cent, and covers
household energy – gas, oil, electricity – and car fuel.
Details of the TEQs system are still being refined, and I have found it
necessary in putting a figure to the per-capita allowance to firm up one
of its flexible definitions, and to re-examine what falls within the scope
of the TEQs personal allowance. I have made the following changes:
1. The full TEQs description refers to ‘a system of flexible children’s
allowances’. I have given children half an adult allowance.
2. To assure equitable access to air travel, I have moved half the
emissions due to air travel into the TEQs personal allowance. The
remainder is available for use by business, industry and government, its
allocation being handled through the auction of the remaining TEQs.
See the box overleaf for background on the issue of equitable access
to high carbon goods and services.
Point 2 above means that the TEQs personal allowance rises to 46
per cent of the total. This, and the half allowances for children, results
in a baseline adult TEQs personal allowance of 4604kg. My thanks to
Rich Hawkins of the zerocarbonbritain team for the emissions and
population data underlying this calculation.
2007 is the baseline year, and 2027 is ‘zero carbon year’. The allowance
for each intermediate year declines by 5 per cent of the original
allowance. Thus for year 1, 2008, the adult allowance is 4374kg.
Let’s apply this to a ‘typical’ household. Cobbling together a great
number of stereotypes gives us a family of two parents and two
children, living in a 1930s three bedroom semi-detached house. They
run a family car of ‘Mondeo’ dimensions, and a smaller ‘Fiesta’-sized
second car. The highlight of their summer is the family holiday to
somewhere warm – southern Spain, for example. Occasionally they
travel as a family by train, but mostly they use the car. Let’s say they
take a trip up to Edinburgh to see a bit of the Festival, and for the
sake of argument, they live in Aberystwyth.
Their TEQs allowance amounts to three times the adult allowance
because the children get a half allowance each. Their household
carbon budget for 2007 is therefore 13,812kg CO2. This needs to
cover fuel for heating, hot water and cooking, household electricity,
fuel for the two cars, and the emissions from their rail and air travel.
In a real household, the emissions from direct fuel use can be
calculated precisely from the amounts of fuel purchased. Assuming
gas for home heating, the gas bills, electricity bills and filling station
receipts cover the house and car. For rail and air travel we need
to multiply the distance travelled by a suitable ‘emissions factor’ to
obtain the CO2 figures. In this example, we’ll use average UK data to
estimate the emissions due to gas, electricity and car fuel use.
Our typical household’s emissions look like this:
Emissions source
kg CO2
Gas
3800
Electricity
1419
First car
2898
Second car
2254
Rail travel
340
Air travel
2968
Total
13679
The relative contribution of each emissions source is clear in the
graphic:
Average household
0
2000
4000
6000
8000
2008
10000
12000
2007
14000
16000
kgC02
We’ll assume gas consumption of 20,000kWh per year. This is typical
of relatively low insulation levels and a boiler several years old.
Average household electricity use in the UK is 3300kWh per year.
We’ll assume that both cars have petrol engines – diesels still
account for fewer than a third of all cars on UK roads. The average
petrol car drives 10,000 miles per year, and emits 180g CO2 per
km. We’ll allow the smaller car lower emissions of 140g per km.
Note the use of both miles and kilometres here – emissions data
is Europe-wide and therefore in official sources always given per
kilometre. Our UK odometers measure in miles. We just have
to remember to convert from one to the other when doing the
calculations.
For rail and air travel I have used the emissions factors calculated by
the Tyndall centre. These are rather harsher than many of the figures
advanced by other sources. There is room for debate here, but we’ll
start from the pessimistic boundary. Any changes will therefore make
life easier rather than more difficult.
Note that business travel is not included in the personal TEQs
allocation. If you have to travel in connection with your work, your
employer would need to buy carbon permits to cover it.
Gas
Electricity
First car
Rail travel
Air travel
The revised emissions for our example family are:
Emissions source
kg CO2
Gas
2956
Electricity
1075
First car
2174
Second car
2029
Rail travel
804
Air travel
2968
Total
12005
and in graphical form:
For this year, our typical family are fine – just under the 2007
allowance, shown by the black vertical line. Some changes are
required for them to meet the 2008 allowance, shown by the red
line.
Let’s take a look at some of the things our family can do to bring
their emissions under the next year’s threshold. In the house,
by installing cavity wall insulation, increasing the amount of loft
insulation and fitting a highly efficient condensing boiler, gas use
can be reduced by 30 per cent to 12,000kWh. Low energy lighting
everywhere, assiduous attention to minimising standby power
consumption, and upgrading to the most energy efficient fridge
Second car
Average household
0
2000
4000
6000
8000
2008
10000
12000
2007
14000
kgC02
Gas
Electricity
First car
Second car
Rail travel
Air travel
16000
freezer can reduce electricity use to 2,500kWh per year. Using the cars a
little less, and the train a little more brings down the transport emissions.
In the early years, in many cases, the summer holiday by air can remain.
A key feature of the TEQs system is that there is no forbidden fruit.You
can use your allowance in any way you like. Keep the annual flight, but
balance it by improvements elsewhere.You can have a 4x4 – but for a
given amount of carbon, you can’t drive as far as you would be able to
in a lower emissions car.
When you join our twenty year, real-time carbon reduction experiment
we will send you a spreadsheet so that you can reproduce these diagrams
for your own circumstances. The free information service at CAT will do
its best to answer any queries that arise.
Finally I just want to offer a detailed view of the possibilities for carbon
reduction in one very focused area. We’ll do more of these snapshots in
future issues of Clean Slate.
References
The main zcb web site from which the complete report can be
downloaded. Printed copies may also be ordered.
www.zerocarbonbritain.com
The Global Commons Institute – home of ‘Contraction and
Convergence’.
www.gci.org.uk/contconv/cc.html
David Fleming’s Tradeable Energy Quotas book.
www.teqs.net/book/teqs.pdf
The ‘Carbon Reduction Action Groups’ web site.
www.carbonrationing.org.uk
The Royal Society’s carbon trading exploration project.
www.rsacarbonlimited.org
The Tyndall Centre for Climate Change Research.
www.tyndall.ac.uk
Tradeable Energy Quotas (TEQs)
There is an important difference to market behaviour between
things covered by the TEQs allowance and those in the open
market. The TEQ allowance is equitably distributed. Anything
where the carbon content is charged for through the TEQ system
is equally available to all citizens, regardless of their financial
means. Goods and services supplied outside the TEQs part of the
national carbon budget are not equitably distributed. Differences
in carbon content are reflected in different prices because the
cost of carbon is wrapped up in the selling price. This helps to
direct customer choices towards lower carbon products and
services using the conventional market signal of price. In the early
years, when the carbon budget is relatively high, there may not be
much difference in cost between high and low carbon alternatives,
because the higher cost of production of low carbon goods may
outweigh the cost of the carbon in the high carbon version. As the
carbon budget is reduced year by year, this will change and the
lower carbon alternatives will be cheaper.
This is fine where lower carbon alternatives exist: a product or
service is not denied to anybody on the grounds of its carbon cost.
Where there is no low carbon alternative, however, inequity rears
its head. A high carbon product or service with no low carbon
alternative will become progressively more expensive as the
carbon budget is reduced. Since there is no cap to the amount of
money available to purchase goods and services, this means that
it will be available only to the better off.
To allow equitable access to a product or service, some or all of it
must be placed within the TEQs allowance. The obvious example
at present is air travel. Therefore as a first hit solution, I have
moved air travel from the open market to the TEQs allowance.
There is room for further debate here.
Refrigeration
In extremis, it is possible to live without refrigeration. The only serious inconvenience for non-meat eaters is in stopping the milk going
off. Food scientists would no doubt raise safety concerns with regard to many other food stuffs, but essentially it is possible. However, the
average household is not ready to give up its fridges and freezers. So what can we do?
The average UK household consumes 3300kWh of electricity per year. Fridges and freezers account for 20% of this, or 660kWh per year.
There are three ways of reducing this:
• Use the existing cold appliances in the most efficient way.
• Upgrade to lower energy appliances.
• Take a different view on the use of cold storage in the home.
Savings Level
Actions required
kWh/year
0%
Average UK fridge feezer
660
10%
Defrost regularly; check door seals are in good order; keep evaporator grid clean (on the
back); don’t open the door more than necessary; keep in the coolest part of the kitchen.
Fit a ‘savaplug’ (if compatible)
600
50%
Either: Upgrade to the best A++ fridge freezer, no bigger than needed.
Or: If you need a large amount of freezer space, have a larder fridge and a separate chest
freezer, both A++ rated
250-300
90%
Make a conscious decision to manage without any freezer space, and upgrade to the most
efficient larder fridge on the market today
60-100
flow batteries: a technology for
storing electrical energy
Arthur Butler
CAT Engineering
In order to address the
challenges of climate
change it will be
necessary to increase
the proportion of
electricity generated
from renewable
resources…
T
his can pose some difficulties in terms of
balancing electricity supply and demand,
because the power produced by many
renewables is quite variable. Electrical energy
is relatively hard to store in large quantities,
so there is growing interest in various storage
technologies, one of which is flow batteries.
Electricity is a tremendously useful and
versatile form of energy, which we have come to
use widely, and is in itself a ‘clean’ fuel. However,
its generation causes considerable pollution,
often more than if the same fossil fuel was burnt
at the point of use, due to both intrinsic and
practical inefficiencies in converting one form of
energy to another. In terms of the environment,
therefore, electricity may not be the best energy
source to use for heating at present, but if we
could generate a larger fraction from renewables
it might become so. There are many ways to
reduce our impact on the environment, but firstly
we should always reduce our energy usage,
perhaps by lifestyle changes, then secondly
increase efficiency, for example by good
appliance design. At present, mains electricity is
produced from a mixture of sources, with around
5 per cent from renewables.
Regardless of how it is generated, the amount
of electricity produced has to match the demand
both instantaneously and in the long term. The
large power stations cannot respond rapidly to
variations in demand, so are used to provide the
‘base-load’ requirement, which is more slowly
varying. Even when electricity is generated from
fossil fuels and nuclear energy, there is a need
to provide quick response power generation
– the alternative is to keep power stations idling,
which is expensive and bad for the environment.
Electricity itself cannot be stored easily, and
usually has to be converted into another form
of energy in order to be stored. One method
that is presently employed is pumped storage.
When surplus power is available, for example
overnight, water is pumped to reservoirs at the
top of hills. When power is required the water
is allowed to flow back down through hydro
turbines generating electricity. Pumped storage
stations, or indeed any energy storage system,
can never be 100 per cent efficient, and they
generate less power through the turbines than
they used to pump the water up to the reservoir.
However, the system allows supply and demand
to be better matched, and therefore power
stations can be ‘turned down’ on more occasions,
so there are reductions in emissions overall and
consequent environmental benefits.
To give an idea of the scale of numbers
involved in energy storage on a large scale, a
single modern commercial scale wind-turbine
has a maximum power output rating of around
3 million watts (MW) and the UK’s largest coalfired power station has a power output of around
4000MW, around 7 per cent of the electrical
power generated in the UK.
There is a big difference between the rate of
energy production (or use), and the total amount
involved, the energy. For example a domestic
electric kettle uses energy at a rate of around 2.5
thousand watts (kW), and a domestic fridge at
perhaps 0.1kW. However the kettle is used for,
say, ½ an hour per day compared to the fridge,
which might be running for 15 hours during
the day. The total amount of energy used by the
kettle in this example is (given by power x time)
1.3 kW hours (kWh), and for the fridge 1.5 kWh.
Domestic electricity is sold in units of 1 kWh.
Overall the energy use, and hence impact on
global warming is similar at a first glance, but
the need to supply peaks and troughs in demand
(e.g. when the country takes a tea break during
the half time of a cup final) has knock-on effects.
For an energy storage system both the power
and total energy stored are important. In order
to store the energy from a single wind turbine
at half its maximum output for a day, we need to
be able to store around 36,000kWh, or 36MWh,
at a rate of 1.5MW. It might be useful to be able
to deliver that energy faster though. (To put that
amount of energy in context, in a whole year an
average house in the UK uses around 3,000 to
4,000kWh of electricity.)
There are other ways of storing electrical
energy, for example lead-acid batteries (more
robust versions of car starter batteries), large
flywheels, generating hydrogen from water and
then burning it or using fuel cells to produce
electricity, high capacity charge storage devices
called capacitors, superconducting magnets, or
even compressed air. However these solutions
may have various drawbacks, including lower
efficiency, higher cost, materials or technology
Electrolyte
tank
Electrolyte
tank
Electrode
–
+
Regenerative
fuel cell
Electrolyte
Pump
Electrolyte
Pump
Ion selective
membrane
Power source/load
Diagram of flow battery principles
that is not fully developed yet, being less durable and unable to store
the large amounts of energy needed or to exchange the energy at
a fast enough rate (power). There may well be a role for a mixture
of these storage technologies though. If suitable superconductors,
which worked at closer to room temperature, were developed
then that method would be highly efficient. Flow batteries are one
existing, if relatively new, technology that may fulfil the requirements
of large-scale energy storage.
How Flow Batteries Work
I’ll start by outlining how a car starter battery works, and then move
on to flow batteries. A 12V (nominal) car battery is made up of 6
cells connected in series, each generating around 2V, depending
on the level of charge the battery is at. In each cell are electrically
conducting plates, made mainly of lead, with sulphuric acid solution
(electrolyte) in between. Electrolyte is a medium containing ions
(atoms with an electric charge) that are free to move, and therefore it
conducts electricity. When electrical energy is applied to the battery,
chemical changes in the plates and electrolyte take place, storing
the energy supplied. The chemical reaction can be reversed and the
stored energy is then turned back into electrical energy.
There are many disadvantages of a system like this, including: the
weight of the lead (a toxic metal) and electrolyte; the energy density
stored; the fact that the plates are involved in a chemical reaction,
and that the hydrogen that is sometimes produced when the battery
is being charged can cause explosions. Major improvements can be
made by designing the battery so that charged (or discharged) fluid
can be pumped out of the battery and replaced with discharged (or
charged) working fluid – hence the term flow battery. The storage
capacity can then be increased by adding more fluid to the system.
You may have heard of fuel cells, in which, for example, hydrogen
and oxygen may be fed in as fuel and electricity and water produced.
A flow battery is similar to a fuel cell to some extent, but the
important difference is that in a flow battery the working fluid is also
the electrolyte. In a fuel cell, the fuel supply chemicals are usually
non-conducting chemicals and a separate electrolyte is used. Fuel
cells are usually not efficient when used in reverse to store electrical
energy, and so are not considered in more detail here.
Hopefully, you now have some idea of what a flow battery is and
what it isn’t, and why it is a promising way of storing electrical energy.
The chemical reaction involved when a battery is charged or
discharged is called a reduction-oxidation, or redox reaction. Loosely
speaking, when an atom or ion is ‘oxidised’ it has less electrons
associated with it after the reaction than before, and when an atom or
ion is ‘reduced’ it gains electrons in the reaction. What happens when
a battery is being charged or discharged is that one chemical form
is ionised and another is reduced. The electricity supplied to charge
the battery flows through the electrolyte in the form of moving ions.
The ions carry electric charge from one chemical form to the other.
This process requires energy to drive it, and the energy is stored in
the chemical changes of the form involved. When the battery is being
discharged the chemicals revert to their original state, releasing the
stored energy, and driving a flow of ions, i.e. producing electricity.
In a flow battery, each cell is actually split into 2 half-cells,
separated by an ion-permeable membrane. The chemical liquid used
on each side of an ion-permeable membrane may or may not be the
same. If the chemicals are different then the membrane needs to be
rugged or cross-contamination may occur, which has a detrimental
effect on the battery’s performance.
Types of Flow Battery
In a hybrid flow battery the working fluid(s) can be pumped through
the battery, but the plates are still involved in the chemical reaction,
for example a solid may be deposited from the working fluid(s) onto
the plates. The involvement of the plates in the chemical reaction may
limit the system life, and the space taken up inside the battery by
the deposits limits the energy storage capacity achievable. Even so,
these systems still offer considerable advantages over conventional
batteries.
There is active ongoing research into hybrid flow batteries and
there are working installations of these systems. Types that have
been investigated include batteries based on the following chemicals:
zinc-halide, zinc-cerium and all-lead.
The zinc-bromine battery was developed by Exxon in the early
70s, and a 1MW, 4MWh test system made by Meidisha was installed
in Japan in 1991. The zinc-bromide system is presently marketed
by ZBB Energy who, according to their website, offer modular
outputs of around 250kW power and 500kWh capacity each. ZBB
Clean Slate 17
claim the system has an energy density of around 80Wh/kg, which
is two to three times that of normal lead-acid batteries. The battery
system is around 70 per cent efficient, and the open circuit voltage is
1.8V. More recently there have been installations with capacities of
0.1MWh–2MWh in various locations around the world.
A Scottish company called Plurion has been developing the
zinc-cerium hybrid system for more than 10 years. It is presently
scaling up to producing commercial units. The chemicals involved
are not highly toxic and are dissolved in methane sulphonic acid
(MSA), which is considered by the US Environmental Protection
Agency (EPA) to be a ‘green acid’ and its use to replace acids such as
sulphuric acid is being actively encouraged.
The electric potential developed by each cell is 2.4V in open
circuit, and the discharge potential of around 1.9-2.1V is higher than
that of other redox battery systems. One way of defining the power
density of a battery system is as the electrical power delivered per
area of plate, and on this definition Plurion claims its system ‘has the
potential to perform at two to three times the power density of any
other existing redox system’. This is important, since it has reduced
system size and cost. The power density can also be defined as
the electrical power delivered per volume of working fluid. Plurion
also says that the system does not require electrolyte management
systems to control ionic fluxes across the membrane, which it hopes
will allow it to supply pre-built, modular, easily installed systems, and
that the working fluids are maintenance free. Plurion is primarily
aiming to produce 250kW, 500kWh units.
True flow batteries are those in which the electric conductors are
not involved in the chemical reaction. This improves capacity and
probably lifetime too. With this system, the storage capacity of the
battery can be increased simply by using more liquid, and the rate
of energy storage or supply can be increased by adding more cells.
This separation makes the system very versatile, and means that
extremely high capacity and durable storage systems are possible in
principle.
There are several possible chemistries that have been investigated
for use in true flow batteries and these include: vanadium,
polysulphide bromide and uranium. Of these chemistries the
vanadium and uranium based flow batteries have the intrinsic
advantage that the chemicals used in each half-cell are the same.
However, in addition to how well the battery works we should also
consider the availability and hazards of the chemicals involved.
The polysulphide bromide flow battery uses sodium polysulphide
and sodium bromide. Both can be readily obtained, but are
hazardous. A company called Innogy developed the technology, and
commercial system installations were undertaken by Regenysis. Plans
18 Clean Slate
were in place to install large-scale functional demonstration units
of the polysulphide bromide flow battery, but for various reasons,
perhaps a mixture of technical, logistical and financial reasons, the
company has ceased trading. It constructed test systems in the
UK, the largest of which would store up to 120MWh of electrical
energy, with a power transfer rate of 15MW, but they were never fully
operational. The battery system was claimed to have a net efficiency
of around 75 per cent. There were also plans for an installation in
Tennessee, but these appear not to have been completed. There are
no reports of other trial installations readily available.
Uranium is a toxic heavy metal, with radioactive isotopes, and
is produced by mining and refining the ore. Worldwide resources
are estimated at around 5 million tonnes of ore, but also around 35
million tonnes in lower concentrations in mineral deposits; around
5 billion tonnes are also thought to be dissolved in sea water, and
could be extracted if necessary. A Japanese university research team
investigated a uranium based flow battery system in 2004. They
proposed using uranium b-diketones, dissolved in aprotic solvents,
and say that they would expect to achieve a higher energy density
than in a vanadium flow battery system. They also researched a
neptunium based redox battery system, which they also expected to
have a greater efficiency than vanadium based systems. However,
there is as yet no information to be found on any demonstration or
larger scale installations of either system.
Vanadium occurs naturally in around 65 different minerals, for
example patronite VS4, vanadinite Pb5(VO4)3Cl, and carnotite
K2(UO2) 2 (VO4) 2.3H2O. Vanadium is also present in magnetite
(iron oxide) deposits which are rich in titanium, bauxite (aluminium
ore) and in crude oil and coal and other deposits containing carbon.
It is estimated that the worldwide resource is around 65 million
tonnes. Vanadium is obtained mainly as a bi-product or co-product
in other chemical extraction processes, and is used industrially,
primarily in steel making, as a catalyst, in superconductors and
in compounds used for dyeing, amongst other things. Vanadium
compounds can be toxic, with the toxicity tending to increase with
higher oxidation of the ion. That said, vanadium compounds are
not strongly absorbed through the gastro-intestinal system, and
are already widely used. With careful handling, and the fact that
the lifetime of flow batteries should be long, the degree of risk
may be environmentally acceptable. A life-cycle assessment of the
environmental impact of both vanadium redox and lead-acid batteries
for use in stationary applications indicates that the vanadium battery
contributes only between 7 to 25 per cent of emissions of key
environmental impact components (CO2, SO2, CO, CH4, NOx) during
its life cycle, compared with emissions from lead-acid batteries.
Practical vanadium flow batteries were invented by Maria SkyllasKazacos – who started research in 1984 at the University of New
South Wales (UNSW), Australia. Other researchers had previously
suggested the use of vanadium, but practical batteries hadn’t been
made because the vanadium 5+ compounds didn’t dissolve well in
most liquids. The UNSW researchers’ breakthrough was discovering
that vanadium pentoxide dissolves adequately in sulphuric acid. The
open-circuit voltage of each cell when fully charged is 1.6V. Battery
efficiencies are around 80 per cent. Battery lifetime is expected to be
in excess of 12,000 full charge-discharge cycles, and greater than five
to ten years. The researchers have found that the batteries respond
rapidly to changing loads and that they have a high overload capacity.
The energy density is approximately 20-30Wh/litre. The present
research is focusing on finding more soluble chemicals in order to
increase the vanadium concentration in the solution, and therefore
increase the power density. The most promising candidate is vanadium
bromide, which allows concentrations twice as high to be achieved.
There are at least three companies installing vanadium flow battery
systems: VRB Power Systems in Canada, and V-Fuel and Pinnacle
VRB in Australia. One of the installations is on King Island, off the
Australian coast, between Victoria and Tasmania. The island gets its
electricity from a wind farm and from diesel generators. The peak
output of the wind farm is around 2.5MW, and the peak electricity
demand is around 3MW. There is a load-levelling system consisting
of a 200kW, 800kWh vanadium flow battery that uses around 70,000
litres of vanadium sulphate solution. Before the flow battery system
was installed, only around 12 per cent of the total electricity demand
was supplied by the wind farm due to mis-matches between supply and
demand. Now around 50 per cent is produced by the wind farm.
This is a good example of the achievement of the high proportions
of energy required from renewable resources that would be needed
for the zerocarbonbritain UK energy strategy proposed by CAT to
succeed. The size of suitable flow battery installations would have to
be be comparable to gasometers, and they would have to be sited in
most large conurbations. One such large 1.5MW, 12MWh wind-farm
load-levelling system is to be installed at Sorne Hill in Ireland. There
are other examples, too: a 2MWh system in Utah has allowed the
electricity supply company to meet peak demands without having to
increase the capacity of the 300km long distribution line. A Japanese
semiconductor factory has installed a 1.5MW vanadium flow battery
system as a power backup. These are the result of hard-nosed
business decisions, not installations for purely environmental reasons.
The Future
As stated, there are successful flow battery installations in use,
demonstrating that the technology can work. Although flow battery
systems are more expensive at present than competing products,
this is changing as production capacity increases. It should also be
noted that flow batteries become cheaper, per unit capacity, the larger
the installation becomes – because essentially all that is needed to
increase capacity is larger storage tanks and more working fluid.
Flow batteries offer an important way of allowing a greater proportion
of electricity to be generated from renewables, which is crucial
for fighting climate chaos. If higher power-density batteries were
developed then this technology offers the appealing prospect of being
able to ‘recharge’ a battery simply by swapping discharged fluid for
charged fluid, allowing very fast recharges, which may one day allow
flow batteries to be used in vehicles. CS
Clean Slate 19
Q&A
Zero Waste
Melissa Harvey, CAT Information Service
Is zero waste really possible?
In the last issue of the Clean Slate, Bryn Fogden, gardening
volunteer, described his inspiring experiments into zero waste,
which included changing his shopping habits and even making
his own toothpaste. But what about zero waste for a busy family
household? Two recent reports, ‘A Zero Waste UK’ from the Green
Alliance and ‘Consumption: reducing, reusing and recycling’
from the Economic and Social Research Council, have looked at
the waste problem in the UK. They also look at case studies of
countries and cities that have set a zero waste target and suggest
some key changes that are needed to reduce our waste (including
a strong waste management policy and a change in approaches to
the production and consumption lifecycle).
What is the problem with waste?
The first problem with waste is that we are running out of places to
put it. In the UK, the amount of waste generated is increasing, and
75 per cent of it ends up in landfill sites, which are rapidly filling
up. This only represents waste produced directly in the UK. A
great deal more is produced on behalf of products imported to the
UK. The other problem with waste is that it represents a misuse of
valuable resources. Most items that are thrown away can be reused
or reprocessed. Some, such as metals and plastic, are made from
non-renewable resources, and recycling them reduces the need for
raw materials and uses less energy in production. Waste is also an
issue on an individual level, for instance every person in the UK
wastes an average of £424 each year on food that is not eaten.
What does zero waste mean?
Zero waste essentially means sending no waste to landfill. Several
countries, towns and businesses, including New Zealand, and Bath
in the UK, have adopted a zero waste goal. Although this is not
necessarily based on whether it is absolutely possible to achieve,
it acts as a motivator for those setting bold waste management
targets. The aim of a zero waste plan is to achieve a closed loop
from production to consumption to waste, and back to production,
rather than a linear route ending in disposal to landfill. This has
been called the ‘cradle to cradle’ approach, because the waste
products from the end of one process become the materials for the
next. A good example is food waste, which can be composted and
returned to the land to help produce more food. Other materials,
such as paper, glass, metals and plastic can also follow this route.
Is recycling enough?
All zero waste strategies agree that recycling alone is not enough,
and stress the need for overall waste reduction. One reason that
waste minimisation has received less publicity than recycling is
that it is more difficult to measure and, in some respects, not within
20 Clean Slate
the control of consumers, since there may be little alternative to
highly packaged produce. The studies find that waste minimisation
efforts need to start before products hit the shelves, with a process
of ‘designing out waste’. This includes minimising and changing
the material inputs to production and replacing the focus of the
economy from products to services and activities.
What about reclaiming energy from waste?
Using the incineration of waste to generate energy is another
option for waste management. There are some risks associated
with incineration, such as accumulation of dioxins and metals, and
a recent study by WRAP has found that recycling is almost always
preferable over incineration in terms of pollution and energy used
and confirms that incineration should only remain an option for
non-recyclable products, if used at all. In most examples, a zero
waste strategy entails 100 per cent recycling, although some
strategies do allow energy from waste.
Will this happen in the UK?
Currently the UK has low recycling levels, at only 23 per cent of
the total waste stream, compared with other European countries
such as the Netherlands, which recycles 65 per cent of municipal
waste. The zero waste strategy in Bath has set an interim target of
50 per cent recycling by 2010 and currently has a recycling rate of
37 per cent, one of the highest in the UK. However there are many
policies around the world that successfully support recycling, with
some locations, for example Kamikatsu in Japan, achieving levels
as high as 80 per cent. Measures to support recycling include high
landfill taxes, household charges for waste sent to landfill, kerbside
recycling schemes, a tax on hard-to-recycle or un-recyclable
products and a blanket ban on recyclable waste going to landfill.
The UK will need to adopt policies such as these to have a
significant impact on waste levels. We will also need to take radical
steps to target the over-production of waste at the producer level,
and move towards a less consumption based economy. Then
everything will be sorted: viva the recycling revolution!
Reports:
Consumption: reducing, reusing and recycling,
a report from the ESRC (2007)
01793 413000 or www.esrcsocietytoday.ac.uk
A Zero Waste UK, a report from the Green Alliance (2006),
020 7233 7433 or www.green-alliance.org.uk/uploadedFiles/
Publications/AZeroWasteUK.pdf
Environmental benefits of recycling, a report from WRAP (2006)
0808 1002040 or www.wrap.org.uk
For advice and information on recycling:
Recycle Now, 0845 3313131 or www.recyclenow.com
members’ info Living on Landfill: 3 weeks on a Croydon tip, CAT gets
M
U
D PED
(an Outline production for Channel 4)
Steve Jones, sector39.co.uk
I
t’s one
thing to be
confronted with
one’s own waste for three
weeks – and something else to
have to live with that of half of
South London. Such was the
central idea for the Ch4 show
‘Dumped’. Take 11 unsuspecting
members of the public and put
them on one of Europe’s biggest
landfill sites for three weeks and
see how they cope…
CAT’s consultancy department
gets an astounding array of inquiries,
including a good many from TV
researchers developing programme
ideas. This one certainly looked like an
interesting and a slightly different project to be
involved with as well as a chance to reach a wider
audience than usual. So, how do you do green for the
mass media? Is it possible without diluting the message too
far? Personally I don’t think the ‘green movement’ as such has
been very successful as yet in engaging a broader audience with its
message.
This recent comment by Tony Juniper caught my eye:
‘The green agenda is often wrongly interpreted as being mainly negative, about
having less and paying more. However, lower congestion, reduced pollution, stronger
communities, warmer homes, lower bills, healthier food and more durable products could all
be part of a low carbon and more resource-efficient future.’
Clean Slate 21
Telling the
world about
dying dolphins
or some
impending
global
catastrophe is
never going to
sell well in the
market place.
Marketing
executives
will tell you
‘don’t sell the
product, sell
its benefits’,
Coke® is more
than a drink,
it’s youth,
freedom,
expression… Green has to mean so much more than do-gooders
selflessly going without; it’s smart, forward thinking, and a new
beginning. Whatever it is, I am fascinated to see how others approach
the subject. Maybe I am being a bit harsh on our green forebears, but
my point is that there is still a long way to go to capture the hearts,
minds and imaginations of the masses. I am not sure, I hasten to add,
that this show is the answer to all that, but it is a genuine attempt to
explore the territory from a different angle. There is a website, a blog
and all sorts of other media arising from this show and others, all part
of building a C4/green interactive multi-media presence.
The backdrop to the whole three week ‘Dumped’ experience is
a Croydon landfill site. Forty acres of quarried out land, gradually
being carpeted in a layer of south London’s finest waste 67m deep
(that’s a 200 foot mountain in old money!). More specifically, this is
the contents of everyone’s wheelie- and dustbins, mixed with an awful
lot of building waste and capped with clay. There is a ceaseless freight
train-like queue of heavily laden lorries disgorging their loads from
dawn ’til dusk, while the big pile just gets higher and higher.
They compact it all down with huge monster bulldozers.
Ironically, you can see the BedZed building clearly
from the top of the tip. Eco-architect Bill Dunster’s
Beddington Zero Energy Development is a high
profile residential project. An integrated, energy
efficient living and working environment… Great stuff
I am sure, but it’s going take more than one BedZed to
offset the energy being thrown into the big hole in the
ground next door. I was staggered how close the dump is
to major housing developments.
Nothing can really prepare you for an up-close view
of the enormity of what we currently throw away. Not
only the physical waste but the financial input – the
plant and machinery that goes with it – those big
dumper trucks for example are £150k each!
Yes, it hits you right away but after
three weeks of relentless queues
of groaning trucks, the true
scale of it all really starts
to sink in. There’s lots
of talk about Royal
Albert Halls full
of waste, by way
of illustration,
but you still
22 Clean Slate
have to really
see it to begin to
appreciate what
an Albert Hall’s
worth of waste
actually looks and
feels like, and
we generate one
every minute of
the day in this
country.
I must add that
the longer I spent
on the tip the more
I came to respect
the complex and
difficult processes
that its workers
were charged
with. It’s no mean
feat processing such an amount of rubbish, and the way it is done is
becoming increasingly sophisticated. The guys are doing a good job;
the problem is the sheer volume of waste.
So to the show… It’s a reality show, ‘Big Brother’ style, and was
aired in the first week of September: four one-hour episodes, prime
time. I’ll assume you’ve not seen it, it being aimed more specifically at
a ‘Big Brother’ audience rather than Clean Slate readers.
The big TV invite had gone out for contestants who were up for a
3 week ‘eco challenge’, all they knew was that they had to have jabs
and turn up with their passports and so many kilos of luggage, ready
for anything. There was a twenty grand pot and whoever was left at
the end of the stint got a straight share of it. Cruelly, the production
crew drove the contestants right past Gatwick on their way to the tip,
just to let them entertain fantasies of Costa Rica right to the last. It’s
just a short jump from the runways to Beddington landfill site, where
a designated quadrant of the tip was to be their home for the next 21
days.
The challenge was this: starting with nothing but a bit
of ingenuity, just how far can you go in trying to build
a life from the waste that the rest of us are currently
throwing away. Shelter, washing and toilet facilities,
cooking, comfort, recreation, all those things we
take for granted. What might the contestants learn in
the process, and would it make good entertainment
viewing?
CAT’s role in all this was to act as technical
advisor on the practical tests the contestants took
part in, and to generally be on hand, ready to rise
to whatever particular challenges arose. It was
both hard work and lots of fun, with plenty of
opportunity for input into the show. Having seen
the broadcast, I am slightly frustrated that the
editors focused mainly on the human drama
side of things, rather than the actual tasks
themselves: quite a few didn’t make the final cut
at all. My first observation was how wasteful
TV is… The numbers of AA batteries they got
through in radio mikes etc, etc. ‘Dumped’
must have cost a lot of money to make, with
a big crew on location and all the support
and materials required and they
dumped a lot of the footage
along with the
rubbish.
The thing that most tickled me was the recycling system eco-aware
student Lawrence set up for the group. Landfill, cans and recyclables,
and compost. It looked so bizarre, set up amidst a landfill site. You
are camped on rubbish, so the idea of having any sort of bin is utterly
pointless. Although I might add that the actual set was constructed
out of 1000 tonnes of sifted skip waste, arranged by the set builders;
real black bag waste would have been far too random, dangerous and
toxic.
It took the contestants ages to rustle up any sense of urgency after
the initial rush to put together an emergency shelter and compost
loo. Finally though, they did rise to the challenge and created a fairly
impressive less temporary shelter, a solar water heater, a kitchen,
décor and all that. They got used to the compost toilet and they even
got as far as making a hot tub and sauna. I found myself wishing
they could have had another week or two, to take it a bit further… I
came away feeling I had learned a lot and had been forced to think
about these things in a much deeper way. Waste, let me tell you, is
BIG business. Big budget. Big politics. Even Bigger machines. And
absolutely essential to our day-to-day life.
I took a tour with the site manager, and got a glimpse of the rate
of change and investment in the whole area. Not that it was said, as
such, but I can imagine that back in the bad old days, the 1970s or
’80s, these piles of waste were still a relatively new phenomenon, on
that scale anyway. Waste was just literally left in old clay pits, quarries
and gravel holes – the whole lot dumped into a huge hole in the
ground, capped off with clay and left to leach toxic chemicals into the
ground water and methane into the atmosphere for ever after.
Times are changing, however, and Croydon’s overseers had just
invested £9m in new plant to compost the separated
organic waste. They are now producing literally
tonnes of compost on a three-week turnaround.
Massive blowers fill the composting silos
with thermophillic bacteria, specially
bred for the purpose, before sucking
them out again on completion. They
struggle to get rid of the compost
they
I started to feel differently about it all; it’s actually not all bad or
out of control, it’s very carefully managed. The foxes, badgers, the
millions of birds, the nesting geese seem to like it, anyway – nature is
very adaptable and never lets an opportunity go begging. When we
so readily endorse developing brown field sites, we overlook the fact
that many brown field sites sustain much more biodiversity than the
green belt does. Part of the Croydon dump has even been designated
an SSSI (Sites of Special Scientific Interest), due to the bird life there.
It confounded my expectations in so many ways.
As for the show, the truth is that the weather was too nice for
the first two weeks so the pressure wasn’t on, with quite a lot of
sunbathing, preening and bickering and other BB type behaviour, and
not enough creative, ‘let’s all build a new eco paradise thing’ going on.
It took a long while to build any consensus in the group and there was
a distinct lack of hard skills available. Especially when the carpenter
walked on the second day, claiming it wasn’t challenging enough and
he didn’t care about the environment anyway, and he was off to Vegas
for a holiday instead – just to prove how much he didn’t care.
But they got there in the end; an ever expanding residence, with
veranda and summer house emerged from the mire, an evolving
range of stoves and ovens appeared, cell phones were charged with
bicycle generators, a wind turbine rented with the income from scrap
sold and generally the contestants slowly got their act together. Tasks
were structured in way designed to introduce key facts about waste
in the UK in 2007, and to confront the contestants with them in a
tangible way. For example, they were given – in 3 huge family-size
suitcases – the 1000 mobile phones the UK throws away every half an
hour, and then told that one of the 1,000 had a £10 sim card in it that
would allow them to call home.
The whole set up was a deliberate ploy to confront the viewing
public with what it wastes. It had a big impact on the contestants
– with only one ‘walking’ and the remaining 10 leaving saying they
would be disappointed with themselves if they didn’t make
personal changes as a result. I hope it had a similar impact on its
audience.
I shall end with a quote from Milan Kundera, who
somewhere said that the definition of ‘kitsch’ is the
philosophical denial of the existence of sh*t. Well, Milan,
to add to your definition, let me offer you a
definition of the ‘s’ word: it’s an unutilised
resource, polite or not… And judging by
what I witnessed in Croydon, we need to
get our unutilised resources together
sometime very soon! CS
Links: http://www.channel4.com/green
generate
fast enough; some of
it goes off to Epsom and Ascot racecourses, some
to Wimbledon, to feed the hallowed tennis lawns, as well as to every
park and green space in the district.
All skip waste is sorted and anything recyclable extracted, firstly by
machine, finally by hand. So really all that is left for landfill is building
waste, sorted non-recyclable skip waste and all those black bags.
Waste management is changing fast, bringing us ever closer to the
realisation that there really is no such thing as waste…only unutilised
resources. Paradoxically, the site
is actually quite beautiful at night,
once the engines and dust have
subsided.
Some landfill stats…
• UK landfill sites are rapidly filling up, yet we remain
one of Europe’s worst recyclers. Our 50 per cent by
2012 target for recycling is lower than what some EU
nations are currently achieving – Germany 50 per
cent, Belgium 75 per cent.
• T his one is my favourite stat, (favourite?)… We in the
UK landfill 3 billion disposable nappies a year, which
will take up to 500 years to biodegrade.
Clean Slate 23
members’ corner
Earthship France
Kevan and Gillian Trott
C
limate change is generating great interest in
sustainable building construction techniques
and domestic lifestyle choices. With this in
mind, a couple from Brighton decided upon (what
some people would consider) the ‘high risk’ venture of
building a totally sustainable off-grid structure called
an earthship in a small village in Normandy, France.
The Trott family believes the earthship offers a viable
solution to a number of environmental problems.
On one level, we are an ordinary family: Kevan is a
chartered surveyor who worked for a local council,
Gillian is a primary school teacher and works in
schools on a part-time basis. We have two children.
The family has a reasonable understanding of global
environmental issues as do an increasing number of
the world’s population. However, what sets us apart
is that we felt so passionately about this situation
that we wanted to do something significant and
so undertook a high financial risk to promote this
particular form of carbon neutral living.
The earthship is a completely independent globally
orientated dwelling, made from materials that are
indigenous to the entire planet. The major structural
component of the earthship is recycled car tyres
filled with compacted earth to form a rammed earth
‘brick’ encased in steel belted rubber. This brick and
the resulting load bearing walls it forms are virtually
indestructible.
Earthships:
• heat and cool themselves naturally via solar/
thermal dynamics
• collect their own power from the sun and wind...
• harvest their own water from rain and snow melt
• contain and treat their own sewage on site
• produce a significant amount of food
• are largely constructed using by-products of
modern society like cans, bottles and tyres
Waste management has become a huge headache,
particularly regarding tyres. Tyres are now considered
hazardous waste and therefore not appropriate
for landfill. Our earthship utilised 750 tyres in its
construction, as well as 5,000 aluminium cans and
10,000 bottles, and other waste products destined for
landfill sites or further processing in recycling plants
(which requires more energy).
Water shortages are becoming an increasing
problem as we enter into a period of much drier
and longer summers. This coincides with a steady
and consistent increase in demand for water. The
earthship in Normandy does not require a mains
water connection since all the water the building
requires is harvested from the roof. It is then used
very efficiently, internally, through a sophisticated
water filtration system.
24 Clean Slate
The supply of energy is becoming insecure at a time of great
demand. Again, the earthship significantly reduces this problem
because all energy demands are fulfilled on site.
Finally, sewage, a polluter along a number of coastlines, is dealt
with efficiently on the plot by a simple planter system that operates
like a reed bed.
History
Since visiting the earthship community in Taos, New Mexico, in
October 2005, Kevan’s involvement in the whole earthship movement
has grown. In July 2006 he became a director of Earthship Biotecture
in Europe.
In August 2005, we discovered a small rural building plot on the
edge of a village in Normandy, France. This soon became the focus
of our desire to build an earthship home. Following a planning
application (Permis de Construire) to the French authorities, in
January 2006, we had to revise the scheme and submit further
information. The complex planning application had to receive
approval from many layers of French Government, including
Le Maire de Ger, l’Architecte Conseil, and also the Directeur
Departemental de l’Equipement (Manche). Finally, in November
2006 (with essential input from Mike Reynolds, the pioneer of the
earthship concept), Kevan achieved Europe’s first planning approval
for a residential earthship.
The Project
Phase 1 Work commenced on site on 16 April 2007. The building
work in the initial six weeks was carried out by the Earthship
Commando Crew. Kevan and Mike Reynolds managed the
construction team and project co-ordination. The Earthship
Commando Crew, led by Mike, is based in Taos and has completed
international demonstration projects in Belgium, Spain, England,
Scotland, Honduras, Mexico, Hawaii and India. In this first
construction phase, the crew put together the structural shell,
installed power and water systems and worked on interior and
exterior finishes.
We felt very strongly that we wanted to provide as much
information to the local community about the project as possible,
especially since it is an extremely unconventional looking structure in
a village of traditional buildings. We also felt it was very important for
people to be aware of the possibilities for living more sustainably that
are inherent in the building’s design.
We organised a presentation before construction commenced,
in which Mike Reynolds, the architect, provided a talk and slide
show that was translated into French. There was so much interest
in the project from the locals that Mike and Kevan
consequently provided informal guided tours around
the building after each working day – up to 150 people
participated. Finally, there was an ‘Open Afternoon’,
so that the village could see what progress had been
made in the first phase, that over 1500 people attended.
The rural community in this part of France is still
very much in touch with sustainable living. Vegetable
patches and some form of rainwater harvesting are
common, as well as older buildings that are oriented to
the south with south facing windows only. Therefore
the villagers seemed to be very open and genuinely
interested in the sustainable facets of the earthship’s
structure.
An independent film maker, Ollie Hodge, recorded
the project as it unfolded, for a tv programme to go
out later in the year. Ollie had already completed an
independent film charting the rise of architect Mike
Reynolds called ‘The Garbage Warrior’ that is to be
shown at the Canadian Film Festival. This includes
footage of Mike and his crew constructing an ‘earthquake-proof’
structure in the Andaman Islands a month after the Tsunami struck
(using the waste materials available).
Phase 2 The second phase of the build is now well underway. The
whole family, along with a fantastic group of committed volunteers, is
working on internal finishes. The floor for the earthship greenhouse
is locally sourced ‘waste’ granite and marble (similar to the floor in
the community earthship at Stanmer Park, Brighton). The floors in
the bedrooms are locally sourced oak boards, which sit on two layers
of softwood flooring, sand and a waterproof membrane. The internal
ceilings are also wooden (softwood) and will be treated with a nontoxic oil sealant. The internal walls are adobe, which is a traditional
mix of sand, earth, straw and water, similar to the ‘wattle and daub’
still seen on old buildings in our part of Normandy. These natural
finishes are very much in harmony with the ethos of the building
– minimum environmental impact.
Phase 3 will be installation of the kitchen, bathroom, lighting
(LED) etc and should take place later this year.
At the end of the project, the family will have a completely
autonomous building that will provide almost everything it needs to
survive an uncertain future in terms of conventional energy sources
and increasingly unreliable water supplies globally. This will have
been achieved using a much smaller amount of toxic materials than
usual, such as cement, whilst re-using a variety of materials that could
have ended up in landfill or recycled, involving further high embodied
energy processes.
Our experience demonstrates that planning permission can be
granted on a forward thinking and unconventional building design
in Europe. Also, if it is not possible for people to attempt a new build,
there are a number of characteristics that could be transferred to
modify existing buildings – rainwater harvesting, systems for filtering
and re-using water, increased thermal mass of existing structures, the
addition of south-facing conservatories to increase solar gain etc.
We hope, as a consequence of taking this risk, to demonstrate that
an earthship can be a really viable way of living more sustainably
in Europe, costing the earth so much less, so that hopefully lots of
others maybe inspired to follow in our footsteps. CS
Further Information
For further details of the project please contact:
Kevan Trott, [email protected]
www.earthship.net
www.earthship-france.com
www.earthshipbiotecture.com – Michael Reynolds
Clean Slate 25
dreamstime.com
Scott Williams
letters
Anniversaries can be interesting times:
for me the first day of the member’s
conference 2007 was also one year on
from my first day at CAT. Starting at
CAT opened my eyes to a world where
the environment and sustainability
takes precedence over almost anything.
Everything in my life has changed:
downsizing from a position as a highly
paid senior manager in the IT industry to a
part-time co-ordinator at CAT has brought
with it a higher quality of life focused on
simplicity and family life; I can recommend
it to everyone. The conference this year
was great: we had loads of fun, learned
loads about zerocarbonbritain, sustainable
living, educating our children and far too
much to mention here. A full report with
pictures will appear in the next issue of
Clean Slate.
We are changing the publication dates of
Clean Slate for administrative reasons; we
need to fit in with holidays and busy times
at the centre. The next edition of Clean Slate
will arrive on your doorsteps on February
11th 2008, one month later than usual.
Clean Slate needs you, your plans, your
thoughts, your projects – whatever you are
doing or planning to do – so please send us
your experiences (good or bad) for inclusion
in future editions of the magazine.
Our online forum continues to grow. Please
visit http://phpbb.cat.org.uk/ or click on the
button at the bottom of the www.cat.org.uk
home page.
Deadline for articles, news, events or general
contributions: 14th January 2008
Scott Williams
[email protected]
26 Clean Slate
Opinions expressed are not necessarily those
held by CAT. We reserve the right to edit letters
where necessary.
Dear CAT,
I am inspired to contact you. I can’t help
but feel that CAT is not doing as much as it
could. You have just spent 6 million on the
Wise Project. How many houses in the UK
could have a solar panel for 6 million? Not
only that, look at the employment this would
create.
Richard Branson wants to give 25 million to
solve the world’s global crisis. Why doesn’t
CAT ask him to donate this? How much help
would the 6 million and 25 million be for our
climate crisis?
Regards,
Jonathan Leigh
Dear Jonathan,
Thank you for your letter, our funding was
given for the particular purpose of providing
education and training to people from all
walks of life in sustainable technologies and
practices. We would not have been able to
raise £6 million to give away free solar panels
to households, even though it is a good thing
to do. Offering such grants to households is the
role of the Government’s Low Carbon Buildings
Programme.
We feel that the funds donated to create the
WISE project will be used most effectively in
providing the education needed to persuade
decision-makers from all sectors of society
to think differently and make vital new energy
choices in their work and communities.
Paul Allen, Development Director
Dear Clean Slate
I can’t believe that you’re promoting the
use of the Fat Trap (Practical Solutions,
CS 64). A truly practical solution to the
problem of pouring fat down the drain is
to use an existing plastic container (ice
cream, margarine, etc) of which almost all
householders will have a surplus.
The Fat Trap merely promotes the myth
that society has to ‘wait for an answer’
to environmental problems rather than
empowering individuals to go and seek
solutions to their own environmental
problems.
Best wishes
Paul Harding
Dear Clean Slate
I have recently upgraded the insulation in
my loft from 125mm to 275mm in line with
current recommendations. But it seemed
to me that the weak point was – and would
continue to be – the hinged hatch cover. This
is notoriously difficult to insulate effectively
as, even with insulation attached to the
cover, there is an area round the edge that it
is impossible to insulate effectively. A fixed
telescopic loft ladder that folded up into the
loft made it impossible to remedy this. Since
the hatch is in the middle of our hall ceiling,
right above the master radiator, this seemed
to guarantee that the maximum amount of
heat would escape!
My solution was to get rid of the fixed
telescopic ladder and replace it with a freestanding one, which I keep in an adjoining
bedroom. This enabled me to make a
secondary hatch cover that overlaps the
hatch by a couple of inches all round. It
comprises a sheet of MDF board, covered
right up to the edges with 300mm of
insulation. This can be slid aside on the
boarded loft floor to give access, and slid
back again to cover – and overlap the edges
of – the hatch as I come down the ladder.
With additional insulation on the original
hinged cover, this makes the hatch the best
– instead of the worst – insulated area of the
loft.
I hope this idea might be worth other people
considering.
Yours sincerely,
Bernard Rofe
Dear Clean Slate
Thank you for another interesting issue of
Clean Slate – I particularly liked Peter Harper’s
article. No matter which way we look at
future emissions we can not escape the most
fundamental point – we produce too much in
the way of carbon emissions, and no amount
of buying our way out will help.
All of us (but especially the high earners/
consumers) have to cut back on our lifestyles
– carbon trading is simply a case of going
on a diet, and paying someone else to lose
weight.
The wealthy will simply carry on with their
present lifestyles, buying in the additional
carbon credits they need, to be paid for
by higher charges to the rest of us. All
that would happen would be that carbon
emissions would continue to rise, and we
would all be worse off financially.
There must be a level amount of carbon
credits for each individual no matter what
their earning potential, with another level for
families, but only for the first two children (the
late Jack Parsons was not the only person
who believes in population control) with no
trading. I am not sure what should be the
penalty once you have exceeded your year’s
quota.
Steve Rainbird
Member’s Bicycle Odyssey
Trish Fenton is on an epic journey to prove
that living lightly on the earth needn’t stop
you having fun and isn’t crazy. To help her
in this aim check out www.bike-for-life.
co.uk... Currently in Majorca helping out
on an organic farm, Trish is looking for
all kinds of moral, spiritual and financial
support and says, ‘Real insanity is living
without a thought for the future we are
giving our children.’
Help stop Climate Change by getting
married or roller-skating to Paris!
The ideas people come up with for raising
money for CAT Charity can be truly innovative.
When a couple told us that they would ask their
wedding guests to donate to CAT instead of giving
wedding gifts, we were over the moon. Not only
does this mean that all the people on the wedding list
get to hear about the vital work carried out by CAT, but
their donations enable us to continue the core education work that
reaches so many thousands of people across the UK.
Just a couple of years ago, one CAT member roller-skated from
London to Paris raising hundreds of pounds in sponsorship. The
publicity CAT received was fantastic, and the funds helped pay
for CAT’s Free Information Service, which answers thousands of
environmental enquiries each year.
Do you fancy raising funds for CAT in an innovative way?
If you would like to, here are a few things you might like to think
about:
Which aspect of CAT’s work would you like to raise funds for?
Perhaps to help support the workshops we deliver to 6,000 school
pupils each year, or does helping to raise funds for Europe’s
Greenest Education Centre inspire you: see [email protected]
CAT’s main website will take you through the myriad work that we
do here www.cat.org.uk
What sort of activity would you like to do? Are you a group of
school pupils that wants to cycle across Britain for sponsorship
money, or are you a lone daredevil who wants to bungee jump to
stop climate change!
You could help secure a greener future for your child by asking
Winner of the 2007 Members’ Conference competition
Ray Jones
What is your favourite
technological invention and why?
The railway, it increased mobility
immeasurably for the Victorians and
apart from walking and cycling is
the best and least environmentally
damaging way to travel.
What technological invention do
you most dislike?
Nuclear power – very difficult to see that in the 1950s, but
the benefits of being without it are now obvious.
What piece of technology do you hanker after that has
not been invented?
Nothing. We are already far too clever by half. Schumacher
was right.
What is the most environmentally sound thing you have
ever done?
Lots – PV array, solar panels, low energy light bulbs. Grow
a lot of our food. Walk, cycle and take the train for
transport.
What is the most important environmental issue today
and why?
Getting the world to understand that time is running out
and the vital necessity of doing the right things as quickly
as possible.
Diary of events at CAT 2008
Biomass: Space Heating Systems
Biomass:
Space Heating Systems
22-26 January
7 Coppicing
to 9 September
Coppicing
4-8 February
7 Sustainable
to 9 September
Woodland Management
Sustainable
Woodland Management
25-29 February
7 Heating
to 9 September
with Wood
Heating
with
Wood
February
29-2
March
9 Ecological
to 14 September
Building from New:
Ecological
Building
The Whole
Housefrom New: the Whole House
2 7-9
September
March and 9 September
Make
Own
Biodiesel
MakeYour
Your
Own
Biodiesel
21
October
–
27
October
7-9 March
Energy
Saving Systems
Week: tours and tips
Wind Power
22
October
–
26
18-22 March October
Christmas
Shopping
Weekends ber
Timber Frame
SelfWeekends
Build
March 25-4 April
Willow: Botany, Planting and Crafts
4-6 April
Ticket
Prices
Identifying
the Lower Plants:
29
Oct
–
31liverworts
Dec 07: and lichens
mosses,
£6
adults,
4-6
April £4 children, £5 concessions
Winter ticket prices
£6 adults, £4 children, £5 concessions
Under 5s Free
Nick Turner
my green solution
for donations at their christening instead of
presents. Perhaps you could advertise our
credit card and legacy leaflets in your business
premises or donate the proceeds from your car
boot sale to CAT…
Make it media friendly: local and national
newspapers, television, and radio, blogs and
podcasts will all help get CAT’s vital environmental
message to more people. CAT’s media team can help
you with this.
Alternatively, there are many other ways to support CAT charity:
Bequests are a legacy for the future. Many people choose to
donate to CAT in their will, knowing that they can continue to
inspire future generations to leave a lighter environmental footprint
on the earth. Please contact [email protected] or 01654
704951 to discuss leaving a bequest to CAT.
The Wales Institute for Sustainable Education is CAT’s largest
project to date. Thousands of students will graduate from CAT’s
Environmental MSc courses, many of them becoming the policy
makers and business leaders for a new sustainable future. To
donate to this exciting new project please contact Gabi Ashton on
01654 704953 or donate online at [email protected]
For CAT to plan for the future with confidence, we rely on
regular donations. Direct Debits, even of small amounts, allow us
to predict our resources and enable us to focus on the important
job of researching and demonstrating the latest in renewable
technologies and disseminating the information to as many
people as possible. To set up a direct debit, please contact Adam
Thorogood on 01654 704950 or [email protected]
Thank you in anticipation of your support.
Tanya Hawkes, Funding at CAT
Clean Slate 27
reviews
The Oil Depletion Protocol – A plan to avert oil wars, terrorism and economic collapse,
Richard Heinberg, Clairview Books, Paperback, 208 pp, £10.99
ISBN-10: 190557004X, ISBN-13: 978-1905570041
Oil, whether you love it or loathe it, is becoming a problem – it seems we are running out and not everyone
accepts the urgency of the issue... Richard Heinberg’s style of writing is engaging and informative, and he clearly
lays out an option that may help the human race to avoid immeasurable suffering. He outlines the use of oil in the
various areas of our lives, and suggests ways in which we can conserve it and deal with diminishing availability.
He provides answers to popular concerns regarding the common sense changes required to enable Colin J
Campbell’s protocol to work. He suggests policy makers throughout the world voluntarily reduce the amounts
of oil we use in a systematic planned way, rather than just waiting for the day it will eventually run out.The book
is stuffed with facts and figures pertaining to our current abuse of oil, and provides a wealth of resources for
people trying to understand why we are standing on a precipice. Campbell’s protocol is simple to comprehend
but understanding how to apply it requires a book – stop what you are doing and read it…
Scott Williams
Food is Different: Why we must get the WTO out of Agriculture, Peter M Rosset, Zed Books
Ltd., £10.99, Paperback, ISBN-10: 1842777556, ISBN-13: 978-1842777558
Peter M Rosset focuses on the global economic systems that have insidiously asserted control over world agriculture
since the early ’90s. His book demystifies a complex subject: the World Trade Organisation and the creation of Free
Trade Treaties. It unpacks the problems that an undemocratic, non-transparent institution causes in many countries,
and is framed by the sacrifice made by one South Korean farmer who immolated himself outside the fifth Ministerial
negotiations of the WTO in Cancun, Mexico in 2003, in protest at the policies of the global commerce system. Food is
Different looks at the shift in balance from national control towards market mechanisms and regulatory bodies, tracing the
effect on small farmers and local producers. Rosset shows how the low-price-setting sleight of hand trickery of the rich
North is killing the producers of the South and degrading the world’s natural systems through mono-cultural production.
Alternatives to cash crop production, such as food sovereignty, are presented as a new paradigm that could allow every
country to define its own food, farming and agricultural policies and thereby protect its own farmers... Well worth the read.
Adam Thorogood
How to live a low-carbon life: the individual’s guide to stopping climate change,
Chris Goodall, Earthscan, Paperback, £14.99, ISBN-10: 1844074269,
ISBN-13: 978-1844074266
Starting with a rather downbeat assessment of the ability of government to take the lead, the author argues that
we must each take action. Only by showing that there is demand for low-carbon technologies and systems will
we persuade our political representatives that they won’t lose office by implementing bolder policies. The book is
easily referenced, with a clear structure and lots of detailed number crunching – moving through space and water
heating, appliances, personal transport, food and more. Besides monetary payback, the cost per tonne of avoided
carbon dioxide (CO2) is calculated. For example, per tonne of CO2 avoided, cavity wall insulation will cost about
£5, investing in large-scale renewable energy (e.g. a community wind turbine) will cost around £50, and your own
renewable energy system will cost several hundred pounds per tonne. If you’ve tried a few carbon calculators and
are keen to reduce your CO2 emissions, this book could be ideal. It’s also an excellent tool for persuading others of
the worth of simple lifestyle changes.
Joel Rawson
28 Clean Slate
WWW
wave power – Joel Rawson
The ‘Island Britain’ scenario included in CAT’s zerocarbonbritain strategy is an
example of how we might become self-sufficient in energy without the need for
fossil fuels. The scenario proposes the rapid development of wave power, to
become one of our main sources of electricity by 2027 (alongside offshore wind
farms). Here’s a quick overview of places to look to see how wave power is doing
at the moment.
The ‘Wave Hub’ (www.wavehub.co.uk) has just been granted planning
approval by the UK Government. This is a kind of offshore ‘socket’ for connecting
and testing wave energy devices, with an undersea cable running to a grid
substation on the Cornish coast 10 miles away. An offshore ‘socket’ like this
should make testing much easier.
The New and Renewable Energy Centre (www.narec.co.uk), in
Northumberland, has carried out small-scale testing of several prototypes – see
the site for case studies. The European Marine Energy Centre (www.emec.
org.uk), in Orkney, has larger near-shore sites for testing both wave and tidal
devices.
Pelamis Wave Power (formerly Ocean Power Delivery) is already installing
offshore wave energy devices (www.oceanpd.com/pelamis). Each tethered
Pelamis (‘sea-snake’) is made up of several cylindrical sections linked by hinged
joints, and sits within the waves. The motion at the joints is used, via hydraulic
motors, to drive electrical generators.
Ocean Power Technologies (www.oceanpowertech.com) is also starting to
install machines. Their offshore, tethered ‘PowerBuoy’ uses the motion of the
waves to drive internal piston-like machinery, which then drives a generator.
A shoreline wave power device installed on Islay in 1989 used an ‘oscillating
water column’: incoming waves forced a column of water to rise and fall inside
a chamber, and this forced air through a turbine. A refined version, the ‘Limpet’
(www.wavegen.com), was installed in 2000. The same principle is employed by
the ‘Wave Dragon’ (www.wavedragon.co.uk), although this is moored offshore.
The British Wind Energy Association is now also representing the burgeoning
marine energy industry (waves, tides and ocean currents). See www.bwea.
com/marine for more information on the potential resource and details of several
existing and proposed machines.
product
Bokashi kitchen waste digester
Having experienced problems with rats taking a liking to
the kitchen waste in my compost bin, I had been trying out
various types of compost containers, none of which proved
rodent proof. Discovery of the bokashi system has solved this
problem.
Bokashi works by ‘fermenting’ the food waste – this can consist of
all types of cooked and uncooked foods including meat, fish and
dairy. The waste is added to the bin with a handful of activating bran
between each layer. Air is excluded from the process by pressing the
waste down, so you can get a lot into the 18 litre container. Once full,
the bin is left tightly sealed for 2 weeks to complete the process; during
this time a liquid is drained from the tap and can be used to keep drains
clear or as a dilute plant food. At the final stage, the resulting material
can be added to a conventional compost bin or dug into a trench in the
garden where it will disappear in a matter of weeks.
Critically, for me, this two-bin system deals with all the kitchen waste for my
family of four and the final compost is proving to be completely unattractive to
rodents!
Edwina Cato
Clean Slate 29
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