Thermal Application Analysis

NREL works with government, municipal, industry, and university partners to find innovative ways to apply geothermal heat to meet residential, industrial, and commercial heating and cooling demands while reducing costs and carbon emissions.

The Cornell University campus is the first geothermal district heating system in the eastern United States.

Roughly a quarter of the total U.S. primary energy demand is consumed as low-temperature heat under 120°C in residential, commercial, and industrial applications. About half of this heat demand is space and water heating at around 50°C in the residential and commercial sectors. Most heating systems supplying this demand are based on natural gas, electricity, and heating oil. Heat from geothermal energy is an environmentally friendly alternative where supply temperature matches end-use application.

Capabilities

• System modeling
• Techno-economic analysis
• Thermal storage and absorption chiller modeling
• Resource assessments

Geothermal District Heating

In 2020, NREL partnered with Cornell University and others to design and develop the first geothermal district heating system in the eastern United States. A district heating system transfers heat efficiently from a central plant through a distribution network to thousands of residential and commercial customers. Between 500 and 600 district heating systems operate in the United States—from geothermal and other sources. NREL works with municipalities, utilities, tribes, universities, and other partners to identify potential for supplying heat from local geothermal resources and realize economic and environmental benefits.

Industry Applications

NREL scientists work with industry partners to identify ways geothermal can meet their heat demands in economic and environmentally friendly ways. Industry applications use about 14 quads of energy each year for process heating and facility heating, ventilating, and air conditioning. With geothermal heat available throughout the U.S. and new closed-loop geothermal systems becoming more common, geothermal can help the United States meet its large heating demands reliably and cleanly. Integration with ground-source heat pumps or absorption chillers provides opportunity for cooling as well as.

Desalination

NREL scientists explore geothermal technologies for creating fresh water from otherwise unusable water. Although most desalination processes use reverse osmosis membranes, thermal desalination processes can provide additional capacity and reduce waste in many applications. Thermal desalination is often constrained by the cost of heat, but geothermal energy can provide otherwise unused, renewable heat. Applied in the right locations, thermal desalination could mean economic viability for water treatment. 

More research is needed before geothermal desalination is cost-effective. However, advances have been made in producing high-quality water from geothermal brines at lower cost than traditional thermal distillation, and membrane coatings have shown the ability to minimize and remove undesired scale formation.

Publications

Geothermal Deep Direct Use for Turbine Inlet Cooling in East Texas, NREL Technical Report (2020)

Desalination of Impaired Water Using Geothermal Energy, Geothermal Resources Council Transactions (2017)

Performance, Cost, and Financial Parameters of Geothermal District Heating Systems for Market Penetration Modeling under Various Scenarios, 42nd Workshop on Geothermal Reservoir Engineering (2017)

Update on Geothermal Direct-Use Installations in the United States, 42nd Workshop on Geothermal Reservoir Engineering (2017)

Characterizing U.S. Heat Demand for Potential Application of Geothermal Direct Use, Transactions (2016)

Use of Low-Temperature Geothermal Energy for Desalination in the Western United States, NREL Technical Report (2015)

View all NREL publications about geothermal research.

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