During the last two decades, the global installed capacity for geothermal electricity has nearly doubled. Despite this recent expansion, geothermal energy is not getting the same level of attention as other renewable energy resources, and it remains heavily underutilized. If the world were able to tap just a small portion of the Earth’s heat, we could provide everyone with clean and safe energy for centuries. Current estimates of our global potential for geothermal energy range from 35 gigawatts (GW) to 2,000 GW. However, simple technological improvements could greatly increase these projections.