The U.S. is among the top countries worldwide in the production of geothermal energy, with output of about 4 GW, according to the U.S. Energy Information Administration. California leads the nation, in large part due to the Geysers field in the northern part of the state, which is the largest dry steam geothermal field globally. Indonesia is another top producer, and that country has an estimated reserve capacity of nearly 28 GW, according to government data, far and away the highest potential output of any ...