Geothermal heating is the direct use of geothermal energy for some heating applications. Humans have taken advantage of geothermal heat this way since the Paleolithic era. Approximately seventy countries made direct use of a total of 270 PJ of geothermal heating in 2004. As of 2007, 28 GW of geothermal heating capacity is installed around the world, satisfying 0.07% of global primary energy consumption. Thermal efficiency is high since no energy conversion is needed, but capacity factors tend to be low since the heat is mostly needed in the winter.
Geothermal heating
The oldest known pool fed by a hot spring, built in the Qin dynasty in the 3rd century BC
Cracks at the historic Town Hall of Staufen im Breisgau presumed due to damage from geothermal drilling
Geothermal power is electrical power generated from geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 26 countries, while geothermal heating is in use in 70 countries.
Krafla, a geothermal power station in Iceland
A geothermal power station in Negros Oriental, Philippines
Geothermal power center in the Usulután Department, El Salvador