Geothermal energy comes from heat generated deep within the Earth, either directly as steam or hot water, or from hot rocks. It is produced through geothermal reservoirs and systems, with high temperature reservoirs above 150°C suitable for commercial electricity production. Power plants use dry steam, flash steam, or binary cycle processes to convert geothermal heat into electricity. Geothermal energy has advantages of being renewable, reducing emissions and fossil fuel dependence, but is limited by the locations of suitable geothermal resources.