Geothermal cooling is different from using geothermal energy to generate power. It uses the near-constant temperature of the earth just below the surface to provide cooling capability. Geothermal cooling is not new; throughout history, people have kept foods and beverages, such as wine, cool by storing them below ground in cellars. For data centers, geothermal cooling is implemented using a closed-loop piping system filled with water and/or a coolant that runs through vertical wells under the ground, filled with a heat-transferring fill.