The US has the largest potential geothermal energy reserve in the world yet only 4% of its total energy usage (15 billion kWh) is from GEP. California has the highest number of geothermal heat pumps out of a total of the nine states that use geothermal energy. Hawaii gets 20% of its power from geothermal power plants. Knowledge about geothermal energy is not well known. This makes getting money for research and development very hard. Developers have also been known to have trouble getting permits to drill on public land and get funding from both the federal government and outside interests. There are, however, two projects that were approved by the Senate to help get EGS out of the pilot stage.