Direct Use Geothermal

In addition to being used to produce power, geothermal waters can be applied directly for a variety of uses, including heating buildings, drying crops and melting snow. Scroll down to read more!

DID YOU KNOW?

The Geysers Geothermal Complex in California is the largest geothermal installation in the world.

Modified Department of Energy graphic showing temeperature ranges for various geothermal uses

Image modified from Department of Energy graphic

Direct Use Heating/Cooling

Geothermal District Heating involves using the heat from geothermal waters directly to heat individual and commercial buildings. Traditionally, such systems have used a combination of production and injection wells and a central pumping station to circulate fluids through a distribution network of piping. Geothermal heat pumps can also be used. These systems can also be designed to pump cold waters in order to cool buildings in the much same way.

Example: Boise, Idaho has had a geothermal district heating system for more than a century!

Thermal Energy Networks (TENs)

Thermal Energy Networks, or TENs, are utility-scale thermal energy infrastructure projects connecting multiple buildings into a shared network with thermal energy sources such as geothermal boreholes, surface water, and wastewater. An ambient loop thermal energy network operates at lower temperature differentials compared to traditional district heating systems, giving them a variety of advantages, including lower heat losses, flexible heat sources, energy storage compatibility and reduced infrastructure costs.

Example: Geothermal Pilot Project in Framingham

Animated graphic demonstrating Thermal Energy Network

Image courtesy of Egg Geo

Deep Direct Use

Deep direct-use (DDU) systems operate at greater depths than heat pumps or other conventional direct use systems and can deploy at a much larger scale. This emerging technology focuses on system efficiencies and could result greater opprtunities for large-scale, low temperature geothermal applications.

Example: Cornell University is exploring the use of heat from deep beneath the Earth’s surface as a sustainable method to warm its Ithaca campus.

Agricultural Applications

Geothermal fluids can be used for a variety of agriculture-related functions, including crop drying, milk pasteurization, and heating greenhouses.

Example: Farmer’s plants grow year-round in geothermal greenhouse in upstate New York.

Aquaculture

Geothermal waters can be used in fish farms.

Example: Geothermal waters are used to heat Salton Sea fish farm that raises tilapia, catfish, and silver carp.

Industrial applications

Geothermal fluids are used in several industrial applications, including food processing, heap leaching and process heat.

Example: First industrial grade food dehydration facility in Latin America at the geothermal power plant of Domo de San Pedro in Nayarit, Mexico.

Other Direct Use Applications

Balneology: Geothermal waters have been used for bathing and health for thousands of years.

Example: The Blue Lagoon in Iceland can see as many as a million visitors per year enjoy bathing in the geothermal waters.

Desalination: Geothermal fluids can provide the heat in thermal desalination processes, or as an energy source for reverse osmosis desalination.

Snow melting: A geothermal heating system can use the heat from the Earth to melt away snow and ice.

Example: Geothermal Energy Keeps New Jersey Driveway Free of Snow

Other Resources

National Renewable Energy Laboratory (NREL): Beyond Electricity

U.S. Department of Energy: Heat from Beneath the Ground – Working to Advance Deep Direct-Use Geothermal

U.S. Environmental Protection Agency: Geothermal Heating and Cooling Technologies

The World Bank: Direct Utilization of Geothermal Resources

ThinkGeoEnergy: Geothermal Energy Production & Utilisation