Geothermal energy

Geothermal energy is a clean energy source that doesn't often get a mention yet it has the capacity to power the world and unlike other renewable energy sources like wind and solar power is "always on".

MIT experts reported in January 2007 that there was enough hydrothermal energy available in the US to generate the entire 27 trillion kilowatt-hours of energy consumed in the US in 2005 [1].

Like Solar power geothermal energy can either be used as a direct heat source for hot water systems or to generate electricity.

In the UK there is no electrical generation but some direct application of geothermal energy amounting to some 3 MW capacity[2]. This is mainly due to the economics of geothermal in the UK.

Other countries in the world are better situated to take advantage of geothermal energy. The US has over 2228 MW of installed generating capacity and 5366 MW of direct use[2].

Maybe this could be another plank in an overall energy strategy and boost renewable energy percentages. Even the UK government freely admits there is greater potential for the technology.

"Future development

It has been estimated that there are 1,550 large industrial sites in the UK where heat-pump systems could be installed, with an average size of 800 kilowatts of thermal power. There is more limited potential for further geothermal plants in the UK as sites need hot rock relatively near to the surface and which is sufficiently fractured to allow the passage of (heated) water. There are areas of hot rocks in the North Pennines, parts of southern England and Derbyshire."

-Geothermal -Current use in the UK

By my calculations based on the heat pump figures quoted above, if all sites were fitted out that would be 1240 MW of thermal power. If the government further invested in electricity generation in areas mentioned above then geothermal can really improve the renewable energy capacity in the UK. For information we currently have one geothermal plant - which provides heating and chilling to businesses and buildings in the Southampton area.

Of course this is just the major projects, liker other renewable technology it is also suitable for home and business use.

I believe that the real future of energy generation is distributed generation where large power stations are merely reserves. Each household or business will have its own locally suitable blend of generation technologies with a grid connection for backup. In order to get to this future we need to develop all these technologies especially the ones that can be "always on" like geothermal. Coupled with a battery system which could be charged over night you can move further away from dependence on a grid connection.

Come on UK government how about some investment in developing UK geothermal energy. After all once the north sea oil starts to run out we have all this drilling expertise and a drilling industry to redeploy.


[1] New Scientist, "Clean Power Under Our Feet" 27 January 2007, p. 4.
[2] World Energy Council - Survey of Energy Resources 2001. All figures from 1999.