Geothermal piping at a geothermal power station. A geothermal power station generates electricity by harnessing the energy in water and steam that have been heated naturally within the Earth's crust. In areas of volcanic activity this hot water and steam lies at or near the surface. The pipes collect the steam and concentrate it, building up high pressures and fast speeds (here, 60 metres a second). The steam passes through turbines to generate electricity. Geothermal power is an environmentally-friendly and renewable source of energy. This is Wairakei Geothermal Power Station, New Zealand. It began generating power in 1958.