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Thermal Energy Networks (TENs)

Terminology Examples Legislation TENs Factsheet download TENs Legislative Policy

Thermal Energy Networks

What Are Thermal Energy Networks?

TENS are the most efficient systems available to deliver climate-friendly heating and cooling equitably to entire neighborhoods.

Thermal Energy Networks (TENs) provide efficient and affordable clean energy heating and cooling to entire neighborhoods through a shared network of water pipes that transfer heat in and out of buildings. These neighborhood-scale systems allow buildings to exchange heat with a number of energy sources, such as lakes and rivers, energy intensive buildings, wastewater systems, or the stable temperature of the earth, and can be designed with backup systems to remain reliable even amid a power outage. TENs can also use shallow boreholes to capture and store excess heat underground for use days or months later. 

Geothermal Networks (aka Networked Geothermal) are a type of TEN that uses shallow boreholes (100 to 750 ft) to harness the relatively constant temperature of the earth (∼55°F) to heat and cool buildings that are connected to the network.  These boreholes can store excess heat to deliver cooling to the network even in times of extreme heat, flattening electric peak demand.  Learn more about networked geothermal technology from Eversource in Massachusetts.

Curious about TEN Terminology? Check out our Terminology Page.

Improved Comfort, Better Efficiency, Cost Savings

For Homes and Businesses


TENs provide efficient heating and cooling regardless of the conditions outdoors.

Higher Efficiency

TENs are the most efficient system available to heat and cool homes and buildings.

Cleaner Air, Improved Health

Replacing gas equipment will cut a significant source of indoor pollution that contributes to asthma risk indoors. TENs eliminate the risk of exposure to dangerous pollutants like carbon monoxide and benzene from home heating equipment.

Cost Savings

With TENs heating bills are projected to be lower because they will no longer include fuel cost (gas/oil). In addition, TENs can stabilize and lower energy bills by providing highly efficient heating and cooling while ensuring communities avoid the volatility of fossil fuel price spikes, creating energy independence.

Better Safety

TENs use water in pipes instead of gas, and use water to conduct heat/energy.

Tens Homes

For Communities

Lower Emissions

Thermal energy networks eliminate the use of fossil fuels in buildings, dramatically reducing emissions. As electricity grids across the U.S. adopt more renewable energy resources, the emissions reduction potential for these systems will increase further.

Local Jobs

TENs provide a pathway for utility workers to transition to clean energy using the skills they already have to install the networks. Watch how thermal energy networks can be a tool to build a pipeline to clean energy union jobs in this video by the UpgradeNY collaboration.

Reduced Demand on the Electric Grid

TENs are the most efficient system known for delivering heating and cooling. These systems provide energy 24/7 regardless of outdoor conditions, thereby flattening the demand for electricity on the hottest and coldest days when peak electric demand generally occurs.

Stored Heat for Later Use

When the energy is not needed, geothermal boreholes can store thermal energy in the bedrock to be used months later, reducing the variability that often plagues renewable electricity generation. This energy storage increases the overall efficiency of the system further by allowing the excess heat in the summer to be stored until it’s needed in the winter.

Equitable Access

By scaling up this technology to transition entire neighborhoods at a time, all buildings on a street segment or neighborhood gain access to clean renewable energy, and renters and low and moderate income customers do not have to pay for the upfront costs of installations.

Lowering Energy Bills

Not only do TENs provide the most efficient heating and cooling available keeping households comfortable for a fraction of the electricity use, they also ensure communities avoid the volatility of fossil fuel price spikes, creating energy independence and greater affordability.

Increased Reliability

Natural gas must travel hundreds or thousands of miles from wellhead to end user, making it vulnerable to single point failures. By contrast, thermal energy networks rely on local sources of energy and systems and can be designed with backup power.

Water Savings

Because connected commercial buildings can be cooled by the networked geothermal system, rather than by chillers (which cool through evaporation), the system can save significant amounts of water. For example, the Colorado Mesa University TEN cut its water use by 60% per square foot of conditioned space.

TENs Communities

TENs Legislation

Currently, six states (Massachusetts, Minnesota, New York, Colorado, Washington, and Maryland) have legislation that either allows or mandates utilities to develop thermal energy network demonstration projects or pilots. The chart below compares TENs legislative provisions by state.

What is thermal energy?


UpgradeNY: NY Climate Week 2023
HEET: From Gas to Geo
Dandelion Energy: How Geothermal Works
Eversource: Networked Geothermal
National Grid: Geothermal Energy Program
Department of Energy, Energy 101: Geothermal Heat Pump

Vermont Community Thermal Networks: How to Develop a Thermal Energy Network, a practical guide to adding thermal energy networks to decarbonization plans for your community.
If you want networked geothermal on your street sign up HERE. HEET is developing a map with site interest to encourage the gas to geo transition.