• The geothermal gradient
  Geothermal gradient
  Geothermal gradient is the rate of increasing temperature with respect to increasing depth in the Earth's interior. Away from tectonic plate boundaries, it is 25–30°C per km of depth in most of the world. Strictly speaking, geo-thermal necessarily refers to the Earth but the concept may be applied...
  
   and associated heat flows from within the Earth

Renewable technology

• Earth sheltering
  Earth sheltering
  Earth sheltering is the architectural practice of using earth against building walls for external thermal mass, to reduce heat loss, and to easily maintain a steady indoor air temperature...
  
  , constructing a building into a hill side or Earth berm to reduce heating and cooling requirements
• Earth cooling tubes
  Earth cooling tubes
  A ground-coupled heat exchanger is an underground heat exchanger loop that can capture or dissipate heat to or from the ground. They use the Earth's near constant subterranean temperature to warm or cool air or other fluids for residential, agricultural or industrial uses...
  
  , using ambient Earth temperature to cool and dehumidify air
• Geothermal desalination
  Geothermal desalination
  Geothermal desalination is a process under development for the production of fresh water using heat energy. Claimed benefits of this method of desalination are that it requires less maintenance than reverse osmosis membranes and that the primary energy input is from geothermal heat, which is a...
  
  , the production of fresh water using heat energy extracted from underground rocks
• Geothermal heating
  Geothermal heating
  Geothermal heating is the direct use of geothermal energy for heating applications. Humans have taken advantage of geothermal heat this way since the Paleolithic era. Approximately seventy countries made direct use of a total of 270 PJ of geothermal heating in 2004...
  
  , methods of heating and cooling a building using underground heat
• Geothermal electricity
  Geothermal electricity
  Geothermal electricity is electricity generated from geothermal energy.Technologies in use include dry steam power plants, flash steam power plants and binary cycle power plants...
  
  , electricity generated from naturally occurring geological heat sources
• Geothermal heat pump, a device used for heating and cooling using the earth as a heat reservoir
  • Direct exchange geothermal heat pump
    Direct exchange geothermal heat pump
    A direct exchange geothermal heat pump system is a geothermal heat pump system in which the refrigerant circulates through copper tubing placed in the ground. The refrigerant exchanges heat directly with the soil through the walls of the copper tubing. This eliminates the plastic water pipe and...
    
    , a method of heating and cooling with the energy of the earth using direct exchange of heat
• Hot dry rock geothermal energy, Heating water in hot deep rock