Geothermal energy is renewable, clean power derived from the thermal energy in subterranean earth. The earth’s thermal energy is created by the decay of radioactive elements in the earth along with the heat from the sun and that remaining from the earth’s creation.Unlike solar power or wind power, geothermal energy is not interrupted by lull times. The technology also has a small carbon footprint in development.eothermal energy can also be used to drive steam turbines. One example of this technology is Calpine Corporation’s geothermal plants in the Mayacamas Mountains in northwestern California. These 15 plants produce up to 725 megawatts daily, making them the largest geothermal energy source in America.