Hot Rocks: the Hottest Renewable Energy Story of the Summer
By Home Heating Guide on June 4, 2009
We all know about the virtues of solar hot water heating and other methods of harvesting renewable energy on a large scale, such as hydroelectric power plants and the countless wind turbines that sit atop hills across the country.
With rising central heating costs and the sensitivity of the traditional fossil fuel markets to external factors such as war and diplomatic relations, the importance of sourcing renewable power is greater than it ever has been. Indeed, if only for the protection of the Earth must humanity look to reducing its carbon footprint, which means moving away from energy derived from coal and oil towards clean renewable sources such as the sun, water and wind. One lesser known source of ‘green energy’, however, can be found deep below our feet.
Whilst geothermal energy is nothing new, a larger scale initiative in Cornwall plans to provide energy for an entire town. Indeed, the Eden Project, in conjunction with its energy partner EGS Energy, has applied for planning permission to bore two holes into the ground of 3km and 4km in depth. Hot granite rocks beneath will be penetrated by injection holes carrying water, which in turn will be percolated by the extreme geothermal temperatures. Then, using a heat exchanger, the hot water will be converted into electricity, which will power the Eden Project buildings primarily with the remainder being fed back into the National Grid.
Harnessing power in this way and on this scale is an extremely exciting project, not least because it provides a glimpse into the future of green energy but so far as the process is predominantly an underground activity, which means that the impact on the environment above remains largely unaffected. It also means that improvements on existing geothermal products aimed at residential properties, which tend to provide heating only services (for the boiler, underfloor heating, etc.), may one day be able to contribute electricity to the homes and surrounding community on a mass scale. Certainly, if homes across the country were powered by this renewable geothermal energy, the carbon footprint produced by Britain would be reduced markedly.