Writing about ground source heat pumps yesterday reminded me that people often refer to them as geothermal, which is a misnomer. Groundsource refers to installing a pipe in the ground and circulating water through it, and transferring the heat of the ground indirectly to heat or cool. Geothermal is a much rarer source of energy, except in some places in the world, including Iceland.
Iceland is a magnificent land of glaciers, waterfalls and steam vents. They also enjoy electricity and heating water from nearly 100% renewable sources. Geothermal energy, which is very hot water or steam extracted from the ground, provides 87% of heating needs throughout the country, and 25% of electricity needs. Electricity is produced from geothermal by circulating steam through turbines, which spin and produce electricity. Remaining electricity needs for the island are met by hydropower, which utilizes the topography of many waterfalls and high volume run-off from snow melts and frequent rains to power turbines. Iceland produced 12.5 Terra watt-hours of electricity from hydro in 2011.
The really interesting thing about Iceland’s energy production is that until the 1970s oil crises, it looked much the same as everyone else’s–based on fossil fuels. During that time, an effort was made to secure the energy future of the country and develop renewable resources. Now, they enjoy almost zero emissions, cheap, renewable power and enough of a surplus that they are considering a transatlantic cable to export power to Britain.