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The Chancellor and the Secretary
of State for Communities and Local Government made announcements
in December outlining challenging new UK government policies
and incentives for zero carbon homes and communities.
As the BedZED eco-village is the most well known and largest
example of a zero carbon development in the UK, this naturally
led to a lot of interest in how things have worked out at
BedZED. The fact that the BedZED wood fired combined heat
and power plant has not been operational for over a year
naturally led to slightly unfair and sensational headlines
like “Great Green Gimmick” (Daily Mail, 8th
December 2006).
In response to this we have set out the current situation
at BedZED and some initial thoughts on the Government's
plans.
Solar panels and wind powered ventilation at BedZED
- photo Bill Dunster Architects
BedZED eco-village – the prototype for zero
carbon homes in the UK
BedZED is the UK’s largest eco-village and is a
Peabody Trust development in partnership with BioRegional
and designed by Bill Dunster Architects.
BedZED was designed to be a zero carbon development –
for us this means to:
1. Reduce the demand for energy
through:
- high levels of insulation and use of natural light and
passive heating and ventilation
- inclusion of low energy appliances and light fittings
in all the homes
2. Supply the remaining energy required from renewable
sources which do not contribute to the devastating
effects of climate change.
Whether a development can be zero carbon on its own site
or whether it will need to draw renewable energy from the
grid will depend on the availability of local resources,
for example high wind speeds, sunlight or surplus biomass.
All zero carbon developments will need to be connected in
to the national grid in order to deal with fluctuations
in energy generation and demand.
In the case of BedZED, BioRegional organised the supply
of wood waste from local street tree pruning to power an
on-site wood powered combined heat and power plant (CHP)
to produce hot water and electricity. Photovoltaic panels
were also incorporated into the design of the homes to generate
electricity from the sun. This strategy makes BedZED net
zero carbon on-site. |
BedZED's
zero carbon status
The BedZED CHP plant was operational at
times during 2002-2005 making BedZED carbon-neutral whilst
it was running, but being a prototype there were some
problems with the technology and the conditions under
which it could operate. The main difficulty was the tar
content of the wood gas which built up in the engine used
to generate the electricity, this was exacerbated by a
planning condition which meant that the plant was required
to shut down overnight, which caused further problems
with tars forming as the equipment cooled down.
Engineers will tell you that most process equipment operates
much more smoothly if you keep it running continuously.
Unfortunately the supplier went into administration before
they were able to solve the technical problems. The plant
has not been running for over a year during which time BedZED
has drawn electricity from the grid and produced hot water
from efficient on-site gas condensing boilers.
Although BedZED is therefore not zero carbon at the time
of writing, compared to a similar home built at the same
time BedZED has reduced its carbon emissions by 56% through
insulation, double and triple glazing and energy efficient
appliances and light bulbs and the photovoltaic cells which
supply 11% of the site’s electricity.
BedZED residents save money on their fuel bills because
they use half as much energy, which for a family home can
amount to savings of £500 per year.
The intention is to make BedZED 100% zero carbon again
in the near future. The BedZED development team are speaking
with another renewable energy company about installing a
new system. It is important that the new equipment is reliable
and the team are taking their time to investigate the technologies
and proposals very carefully before making a decision.
Residents enjoy the communal space, and provisions
for cyclists and pedestrians
photo - Marcus Lyon
Our response to the Government
We will be submitting a formal response in due
time and passing on our practical experiences outlined
above, but we do have some immediate thoughts on their
announcements:
The government definition of zero carbon seems to suggest
that all energy should be generated on site. However,
BioRegional’s view is that generating all the energy
on-site from renewable sources is not always possible
or the best thing to do. It might be better to generate
some of the energy off-site or
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from larger renewable energy
plants supplying the wider community. In all cases it is
necessary to establish an energy service supplier as developers
themselves are really in a different business.
One other factor which BioRegional believe the government
should take into account would be a fairer price for energy
produced by small scale renewable energy generators. The
renewable energy produced at BedZED or comparable projects-
who have to be connected to the grid to even out demand
fluctuations - is purchased for a substantially lower price
than the energy pulled off the grid. In Germany the price
paid is the same whether you are buying or generating and
in California a premium is paid for renewable energy. A
fairer price would improve the returns on investment for
renewable energy producers and encourage a much wider take
up.
Our next generation zero carbon developments
Building on lessons learned at BedZED, BioRegional are
also working on next generation zero carbon communities.
For the past two years BioRegional have partnered with
WWF on an initiative called One Planet Living®, one
aim of which is to work with local partners to build sustainable
communities around the world. The communities are guided
by a set of ten principles – one being zero carbon.
www.oneplanetliving.org
For the One Planet Living London project, which will be
zero carbon, we are working with sustainable community development
company BioRegional Quintain Ltd(1) to find a site in London’s
Thames Gateway to build a 2,000 home mixed use development
there. Research carried out by BioRegional on this project,
known as Z-squared, is available on our website (View
the report here). BioRegional Quintain Ltd are already
going ahead with zero carbon developments in Brighton (with
Crest Nicholson) and Middlesbrough, with building starting
on site in 2007.
It is not entirely simple to build new zero carbon developments
but BioRegional have applied the approach in a variety of
scenarios now and we can see how it will be both technically
feasible and cost effective. In the coming year BioRegional
is turning its attention to practical demonstrations of
zero carbon and One Planet Living in existing communities.
BedZED has played a key role in achieving these world first
zero carbon policy proposals from the UK government by showing
in a real and practical way how zero carbon homes can be
a part of the mainstream.
View
the UK government's zero carbon policy papers
1. BioRegional Quintain Ltd aims to lead
in the creation of sustainable communities throughout the
UK by the comprehensive application of ‘One Planet
Living’ principles to a dynamic and innovative approach
to property development. The company is owned 50-50 by Quintain
Estates and Development PLC, and BioRegional Properties
Ltd, a company founded by eco-entrepreneurs and BioRegional
Development Group, a registered charity. The charity benefits
from a share of profits mechanism to support continued cutting
edge sustainability research and development work.
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