Ryan Crighton, 10th November 2011
Scotland is being urged to embrace geothermal energy if tests confirm it can be produced in the north-east.
The Press and Journal revealed yesterday that granite located several miles beneath Aberdeenshire could hold the potential to create heat and generate electricity.
Four miles underground, the Earth’s temperature typically rises by 150C – but in areas where there is granite the temperature can rise by 210C.
Scientists believe so-called “hot rocks” could lie below Peterhead, Inverurie and areas around Stonehaven, and that fluid could be piped through them to power electricity-generating turbines.
Scottish Enterprise is funding a major study to establish if a test plant could be built in the north-east.
Last night, Gaynor Hartnell, head of renewable power at the Renewable Energy Association, said: “Geothermal is absolutely something which should be embraced in Scotland.”
In Iceland, where geothermal technology has been developed over the past decade, the power is now on the verge of being exported to the rest of Europe.
Ragna Sara Jonsdottir, of Iceland’s state-owned and largest energy company, Landsvirkjun, said nearly every home in the country is now heated with water from geothermal.
The company is considering laying an underwater cable to sell electricity to more than 1million homes throughout the UK and the rest of Europe. Renewable energy produces all of Iceland’s electricity, with 70% coming from hydro and the other 30% from five geothermal plants.
Selling the excess is expected to pump nearly £300million into the island nation’s economy.
Ms Hartnell said the UK needed to urgently develop a comprehensive geothermal exploration licence regime, alike to those used in the oil and gas industry, if it is to reap similar benefits.
“These licences would grant the licensee the exclusive right to exploration and exploitation of geothermal resources over a defined area for a defined period of time and are essential to provide investor confidence as the industry develops and grows,” she said.
“The concept is very similar to the exploration licences found within the oil and gas industry and the legislation has been adopted by most countries within Europe.”
EGS Energy has been given permission to build the UK’s first geothermal plant at the Eden Project in Cornwall.
Based on the data he has seen, the firm’s managing director, Guy MacPherson-Grant, is not convinced the north-east holds as much potential as other parts of Scotland, particularly the Cairngorms.
He said if the potential was there then it would be an economic boost for the area, however. “The UK is not going to become Iceland – but if we can find the heat in granite then we could build some plants,” he said.
“A four-megawatt plant would create electricity for thousands of homes and if you can send the heat to a hospital or schools, that is when you become really efficient.”
The EGS plant at Eden will consist of a two-borehole system – one injection well and one production well, both around three miles deep.
Water will circulate between the bottoms of the two wells, where it will be heated by the hot rocks and returned to the surface at a temperature of approximately 180C.
At the surface the heat will be extracted to drive a binary turbine to create electricity and provide hot water.