Home energy generation

• The Guardian,
• Tuesday June 3 2008

Solar thermal By far the most popular green technology in Britain, these units convert sunlight straight to heat. They are fitted to roofs around the world to provide hot water, thus saving energy.

Combined heat and power units These generate heat and electricity from the same unit. Small-scale plants can heat and power single houses but larger ones can power neighbourhoods or estates. Expected to become very popular as the price reduces.

Heat pumps Exploit the difference between underground temperatures and those in buildings and act like a fridge in reverse. Common in Scandinavia and the technology is growing fast in the UK.

Micro-hydro Energy from running water is converted to electricity. These units are being fitted to old mill races, and are being installed in rivers. Depending on flow, they can provide enough electricity for hundreds of houses.

Solar photovoltaic panels and film Sunlight is converted directly into electricity. The technology is developing rapidly as billions of dollars are invested in it in the US and China takes over production lines.

Micro-wind Small-scale wind turbines generate electricity. Companies and householders are erecting their own turbines to become more self-sufficient as electricity prices rise.

Biomass boilers and stoves Burn wood chips and pellets to provide heat and power.