In the first of a series, we visit the Hellisheiði plant, which provides 300MW of power – and Reykjavik’s hot water
Thanks to its position on a volatile section of the Mid-Atlantic ridge, Iceland is a world leader in the the use of geothermal energy, and of the six geothermal power plants in Iceland, Hellisheiði (pronounced “het-li-shay-thee”) is the newest and largest. Fully operational since 2010, it sits on the mossy slopes of the Hengill volcano in the south-west of the country; a green and placid-looking landscape that belies the turbulent geological activity rumbling beneath it.
To access the potential energy under the surface, wells are drilled thousands of metres into the ground, penetrating reservoirs of pressurised water. Heated by the Earth’s energy, this water can be more than 300C in temperature, and when released it boils up from the well, turning partly to steam on its way. At Hellisheiði, the steam is separated from the water to power some of the plant’s seven turbines, while the remaining water is further depressurised to create more steam, used to power other turbines. At its maximum output the station can produce 303MW of electricity, making it one of the three largest single geothermal power stations in the world.
from Sustainable development | The Guardian