The Apples of Hesperides

Reducing carbon emissions through home generation is an impactful and satisfying thing to do. But, before you start thinking about generating your own heat and power at home, it is worth looking at how you can reduce the need. Britain has some of the oldest housing stock in the developed world with 8.5 million buildings over 60 years old. Standards of insulation even in new homes are pretty poor compared to what they could be (only 743 homes built since April 2008, 0.24% of the total, are rated in the top energy performance band) and are virtually non existent in older properties. It is possible to insulate a house so that it needs no heating at all with the heat given off by the bodies and appliances being sufficient. Even if your ambition doesn’t stretch that far you will find lots of useful advice and resources at the Ecovation Project website.

If you want to generate your own electrical power, from April 2010 there was a new regime for financial support. Rather than giving grants for installing equipment, the government has introduced payment for the power generated. Called a feed-in-tariff, it provides a payment ranging from 9p to 41.3p for each kW hour of electricity produced. The amount varies by the type of technology used, when it was installed  and whether it is already registered with another scheme called ROCs. A similar scheme will be introduced in April 2011 to cover the home generation of heat.

In terms of technologies, the ones worth looking at are;

Photo-Voltaic Thermal (PV-T)
This is a combined heat and electricity generating unit that provides maximum use of available solar energy. The big advantage of this system is that it prevents the electricity generating device from losing efficiency as it heats up. It will generally provide 35% more electricity than a standard PV panel and enough free heat to offset a low energy building’s annual heating requirement. You can get more information here.

Solar Hot Water
These are simple devices for heating up your hot water supply. They will still have an impact during the winter months but will require an additional system for topping up but you can expect a system to be able to provide about half of your annual requirement.

Heat pumps
These work a bit like refrigerators in reverse in that they take the heat out of the air (or ground) and concentrate into a space to warm it up. If you are going to use a ground-source pump you do need more space available than that found in most urban gardens. Air source pumps can still extract heat down to about -200 C so are suitable for typical British winters.

Bio-Mass
Many people think it is strange to think that burning trees is ok but it is so long as they are being planted again. There are systems that use logs, wood chips or wood pellets, the later being particularly flexible and suitable even for use in smoke-free zones.