将下列段落翻译 Geothermal electricity is electricity generated by 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 24 countries, while geothermal heating is in use in 70 countries. As of 2015,worldwide geothermal power capacity amounts to 12 .8 gigawatts ( GW ) ,of which 28 % or 3 548 megawatts are installed in the United States. International markets grew at an average annual rate of 5 % over the last three years and global geothermal power capacity is expected to reach 14.5 ~ 17.6 GW by 2020.Based on current geologic knowledge and technology, the Geothermal Energy Association ( GEA ) estimates that only 6 .5 % of total global potential has been tapped so far, while the IPCC reported geothermal power potential to be in the range of 35GW to 2TW. Countries generating more than 15 % of their electricity from geothermal sources include Salvador, Kenya, Philippines, Iceland and Costa Rica.