What's Happened to Geothermal Energy?
While the A-List celebrities of the renewables world such as solar and wind often get the headlines, particularly here in the UK, there are plenty of other energy sources that have the power to transform our world and lower our collective carbon footprint.
To find out more about geothermal energy you have to go somewhere that has abundant resources and is using it well. There are places in the US, particularly around sites such as Yellowstone Park, that are exploring the technology but if you want a country that is making the most of their underground heat, then Iceland is the perfect location for a visit.
What is Geothermal Energy?
Geothermal energy as a power source has been considered by many countries since the turn of the 20th century. There are areas in the world where underground volatility produces enough heat and power – often more noticeably seen when a volcano become active – and find a way to harness this energy has been the Holy Grail for over a 100 years.
Most of the recent power stations have relied on the heat being close to the surface but with improved drilling technology it could be that, in the future, less volatile areas, including the UK, will be able to access it. In a place like Iceland, where the crust is relatively thin, there is plenty of opportunity to harness geothermal power and turn it into valuable heat and electricity.
Geothermal power across the world has increased by about 20% in the last ten years but there is still the potential to develop it a lot more in the future. In the UK, the potential for geothermal energy was first examined by the government of the day in 1973 when there was an oil crisis. Nothing was done at the time but many scientists believe there is good potential to develop this form of renewable energy in the future. For the moment, most of the attention has been on heat recovery systems that work on a much smaller scale.
The Hellisheiði Geothermal Power Plant
Iceland has no less than six geothermal power plants of which Hellisheiði is the latest and the biggest. Maxed out, it can produce over 300 MW of electricity and provides the hot water for the country’s biggest city and capital Reykjavik. Compared to the UK, Iceland is rich in geothermal resources and the Hellisheiði power plant is situated right next to the Hengill volcano. Holes have been drilled into the ground into reservoirs of water that is at about 300 degrees centigrade, creating a mixture of steam and water that can be used to drive the plant’s 7 turbines.
Icelanders are rightly very proud of their green technology and the power plant is open to the general public to come and see how things work. They regularly run exhibitions and get people visiting from all over the world including the UK.
The biggest geothermal power plant in the world is currently in California, another place with a volatile landscape. The Geysers Geothermal Complex lies to the north of San Francisco and is made of up of 15 plants that are capable of producing 750 MW and has been operating since 1960.