Dry Drayton Green Group - THE GREEN PAGE
Green Group Events
The Grow-it-yourself Get-together on the afternoon of Sunday 15th June was well attended. Allotment holders showed other local growers round and shared information on plants and their growing. There was an exchange of plants and produce, which can be continued at the regular Thursday coffee mornings in the Village Hall. If you find you have an excess of any vegetables or fruit through the summer, please bring them down, to give or sell to make money for good causes.
The Green Group is planning a new series of public meetings in the Autumn, starting on Tuesday October 7th. These will deal with practical action to reduce carbon emissions from the home, and travel, and other related subjects. If there are topics that you would like discussed, please let the Green Group planning team know. In the note below, Rob Howard highlights key issues involved in moving toward carbon neutral homes.
IS IT POSSIBLE FOR BUILDINGS TO BE CARBON NEUTRAL?
As part of its Green Agenda the government has stated its intention to make all new houses carbon neutral by 2016 and all other buildings carbon neutral by 2019. What does this really mean and is it achievable? It means that there should be zero net emissions of carbon dioxide from all energy use in a building. It is hard to see how this could be achieved without buying in energy from green energy suppliers using renewable sources of generation. The government would like buildings to become carbon neutral within their own sites. What would this mean? Firstly energy use should be minimised by very high levels of insulation and renewable sources of fuel – wood or wood chips, for example. For new buildings it is possible to invest in ground source heating using heat pumps to upgrade the heat from the ground. This involves capital expenditure and still uses electricity to enable heat pumps to upgrade the temperature from the soil. Small wind generators are unlikely to be economical at a domestic scale and solar panels are best for hot water, although there are signs that photo-voltaic panels generating electricity may come down in price. The problem then becomes one of storing the electricity for periods with no wind or sun.
Carbon neutrality is one of the goals that politicians like to set to capture the public imagination. They will probably no longer be in power when the goals are due to be met. More realistic is the energy rating of buildings where the Code for Sustainable Homes sets six levels of CO2 emissions, with carbon neutrality as the highest. These are assessed in the Home Information Packs, soon required for selling any house, and will encourage a gradual improvement when the code levels become as familiar as miles per gallon for cars.
Carbon Neutrality is most likely to be achieved in larger developments such as one that was built in South London in 2002 called BedZED (Beddington Zero Energy Development). This provides 82 homes plus workshops. It was designed to be carbon neutral by using a high population density and very high levels of insulation to eliminate the need for any space heating. It recycles water and is largely built from recycled materials sourced from nearby. There is a small Combined Heat & Power (CHP) plant serving the whole site with hot water. The design is characterised by glazed balconies to collect heat from the sun, and colourful ventilation cowls that provide controlled ventilation to a tightly sealed building. Further information can be found in this YouTube video and the project has been monitored at www.bioregional.com. This monitoring has shown that, compared with a typical home, space heating is reduced by 88%, hot water by 57%, electricity use by 25% and water by 50%. The CO2 saved is 147 tonnes per year and costs are reduced by £3,847 per year. This is an impressive achievement although not full carbon neutrality. It does show what can be achieved with large, purpose-designed, projects but carbon neutrality with single, existing or even new, homes will be far more difficult.
For further information on these topics, or to join in the Green Group planning, please contact:
- Rob Howard 780644 robhoward@constcom.demon.co.uk
- Julian Paren 789673 julian.paren@gmail.com
- Sandra & Bill Martin 782705 sandrabill@leisureconsult.freeserve.co.uk