Geothermal power station. View across the Blue Lagoon towards Svartsengi geothermal power station in Iceland. At centre right, bathers enjoy the benefits of the Blue Lagoon, an artificial lake which is constantly being filled with hot waste geothermal water from the power station. The water has a similar salt content to sea water. About 1000 tons of the water flow into the lagoon every hour, gradually seeping into the surrounding volcanic lava. Geothermal power uses the Earth's natural heat to generate electricity. Iceland is a perfect area for harnessing this power as it lies on the boundary between two continental plates, and the Earth's crust is thin.