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Thermal Energy Networks (TENs)

What Are Thermal Energy Networks?

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

Thermal Energy Networks (TENs) provide efficient, affordable and reliable 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 sources and sinks, such as energy intensive buildings, wastewater systems, underground subways, or the stable temperature of the earth. TENs can even use shallow boreholes to capture and store excess heat deep underground for later use days or months later. 

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. 

Geothermal Networks (aka Networked Geothermal) are a type of TEN that uses shallow boreholes (100 to 700 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.



A single family home with white walls and a brown roof.


Homes and Businesses


  • Comfort: Both heating and cooling
  • Health: No indoor combustion, improved indoor air quality 
  • Efficiency: Less energy used to heat and cool your building 
  • Affordability:  Customer heating bills are projected to be lower because they will no longer include fuel cost (gas/propane)

Safety: Pipes are filled with water


A neighborhood of homes connected through pipes.



  • Lower Emissions: The only emissions for a thermal energy network system come from the fuel used to generate the electricity used by the heat pumps in the buildings.
  • Pathway for workers: Workers who have built and maintained the gas pipeline network can use existing skills to install thermal energy networks
  • Efficiency and 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 there is peak electric demand.
  • Thermal storage: Networked 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.
  • Local energy independence and reduced price volatility: customers will be protected from volatile energy price spikes because the energy is always available and sourced locally. Thermal energy networks combined with local electric generation can achieve 100% energy independence for entire communities.
  • Reliability: Natural gas must travel hundreds or thousands of miles from wellhead to end user, making it vulnerable to single point failures. The thermal energy is local and systems are designed with backup power.
  • Reduced water use: 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.

TEN Sites


There are various operational thermal energy networks throughout the country that vary by energy source. The map below shows states that have examples of different types of TENs.

Mapchart Map

TENs by Energy Source  in the United States

TEN Legislation


TENs Leg

Currently, only four states (Massachusetts, Minnesota, New York, and Colorado)  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.

Brand Compliance With Ots