Trapping underground heat to create energy is a way shale oil and fracking companies are trying to create clean energy. Chevron, BP and Devon Energy are part of a group of companies investing hundreds of millions of dollars in geothermal projects. New technologies that can drill thousands of feet below the earth's surface make it possible to reach more geothermal energy inside the earth's surface. This could power 65 million homes in the US by 2050, according to the Energy Department.