The BBC has a report on interest in geothermal power in Scotland - Cairngorms and Lothian hot rocks potential highlighted.
Hot rocks far below the surface of Scotland offer a means of generating limitless amounts of electricity, according to a new study.
Ed Stephens, a geologist at St Andrews University in Fife, said the Cairngorms and East Lothian have the potential for geothermal systems. He said more research would be needed on how to exploit the resource and overcome expensive drilling costs. Germany and Australia are already developing geothermal projects.
Mr Stephens' study used data gathered in the 1980s. He said geothermal's potential in Scotland was again topical because the Scottish government had added it to its list of renewable energy resources.
Hard granites in the eastern Cairngorms and running towards Aberdeen offered some of the best sources of hot rocks, Mr Stephens said. The origin of the heat is the radioactive decay of uranium, thorium and potassium contained within the rock.
Mr Stephens said this heat accumulated slowly over geological time and granites deep in the Earth's crust have become repositories of "effectively limitless supplies of thermal energy". Electricity could be generated by pumping water down bore holes to create steam to drive power plants.