Ground-source energy

Ground-source energy involves the exploitation of energy stored in the ground (bedrock or soil) or in groundwater and is an environmental friendly energy alternative:

• Renewable energy is collected from your own garden, without the need for expensive and polluting energy transport.
• You control your energy system, thereby avoiding unforeseen cost escalations.
• The collected energy is unobtrusive, i.e., noiseless and invisible.

By 2007 the net production from ground-source energy in Norway is approximately 1.3 TWh.The corresponding number is 10 TWh for Sweden, having similar natural conditions compared with Norway. Unofficial list of large Norwegian ground-source energy installations.

Ground-source energy involves the exploitation of energy stored in the ground (bedrock or soil) or in groundwater. Using a heat pump, heat from the ground can be used for space heating and heating of tap water. The stable temperature of the ground and groundwater over the course of one year provides good operating conditions for heat pumps. Approximately 70% of the heat that is distributed in a building may come from the ground, while the remaining 30% is electricity needed to power the heat pump.

For individual households, ground-source energy will mainly be relevant for heating purposes, while some larger buildings may require both heating and cooling. Switching between cooling and heating is optimal, and gives the system low investment costs, a short pay-back time, and major savings in subsequent years. It is also worth noting that in this context we are talking about brine-to-water heat pumps. A prerequisite for using ground-source energy is a building that has a waterborne heating system (water-filled floor heating or radiators).
Ground-source energy, where energy is extracted from shallow depths (<300 meters), mainly consists of solar heat stored in the subsurface plus a small heat contribution from radioactive elements in the bedrock.

A dear child may have many names

Ground-source heat/energy, geoenergy, earth energy, geothermal energy, energy storage in the ground, underground/borehole/aquifer thermal energy storage, rock energy, groundwater energy etc, are names more or less referring to ground source energy. Common for all these terms are that they relate to the ground, either the bedrock, soil or groundwater, for extraction of energy.