Perfect TENs

Thermal energy networks (TENs) are scalable, effective solutions for climate-friendly heating and cooling in neighborhoods, campuses and institutional buildings.

TENs are comprised of equipment and distribution infrastructure that provide heating and cooling through a shared network of water pipes that transfer heat in and out of buildings. They use various thermal energy sources, such as groundwater, geothermal boreholes or surface water, and can exchange heat with nearby energy sources like lakes and rivers, energy-intensive buildings or wastewater systems.

WSP in the U.S. is helping to implement TENs as efficient and carbon-reducing solutions for heating and cooling, especially in dense urban environments and challenging retrofit conditions. Their implementation poses distinctive challenges, but the long-term benefits are outstanding.

TENs move water-based energy transfer fluids through the pipes to circulate thermal energy between the thermal source and geothermal heat pumps in buildings. They can improve a neighborhood’s energy resilience TENs and create Future Ready® communities through several long-term benefits.

By using thermal energy in the network, geothermal heat pumps provide energy savings for customers. Renewable energy sources like geothermal and waste heat can significantly reduce carbon emissions, compared to traditional heating and cooling systems. These networks can help flatten demand on the electric grid by providing heating and cooling regardless of weather conditions and eliminate potential future needs for new electric infrastructure. 

We see TENs as another strategy to help buildings decarbonize. These systems can help buildings avoid significant electrical infrastructure typically for full-building electrification projects, and can also benefit electrical grid constrained areas by avoiding related, increased electrical loads for full-building electrification projects. Connected existing buildings will likely utilize hybrid approaches with TENs addressing decarbonization for specific hydronic heating systems, while separate electrification strategies using heat pumps address the rest.. 

Traditional systems also rely on fossil fuel transport, which makes them vulnerable to failures, while TENs leverage local sources to provide consistent heating and cooling. Furthermore, the interconnected nature of TENs means that they can distribute energy across a network of buildings, potentially reducing reliance on a single source. 

Canada and various European nations have leveraged TENs for some time, and in recent years, similar projects have gained traction in the U.S.

TEN projects are underway in New York and Massachusetts, while states such as Washington, Vermont and Colorado have passed TEN-enabling legislation to support cleaner, more equitable energy sources. These pursuits must contend with specific U.S. constraints, such as aging gas networks that would require replacement and the cost comparison between TENs and individual building electrification. We pay close attention to the Building Decarbonization Coalition’s TENs State Legislation resource for periodic updates across the nation.

To support New York State Utility Thermal Energy Network Jobs Act (UTENJA), we have been fortunate to work with Con Edison’s Thermal Energy Network team. We’re collaborating with Ecosystem on two pilot Con Edison projects, including a TEN at Rockefeller Center in New York for the landmark’s 24-hour cooling system. With that project, we’re distributing energy between neighboring commercial office towers.

In Manhattan’s Chelsea neighborhood, we are recovering heat from a commercial office tower that has two data centers that require 24-hour cooling. In this case, the TEN distributes the heat produced by these data centers to public buildings that support nearby disadvantaged communities, providing hot water, heating and cooling year-round.

The TENs that we are developing in New York are near the buildings and neighborhoods that they’re servicing – just about a block and a half away, in both cases. That proximity is one of the limitations of implementing TENs.

Specifically in the U.S., another challenge for building owners is the existing infrastructure. Owners must ensure that a building can readily utilize the produced heat, and in some cases the building needs extensive modifications to do so. Those modifications also need to allow for system expansion upgrades to potential new customers and thermal resources.

An important consideration is the heat recovery potential from significant buildings that are based in different pockets of cold climates. These buildings can take advantage of the system because they require space heating outside of critical facilities, such as healthcare facilities have reheating needs. Owners should consider these factors for optimal implementation.

TENs offer exciting possibilities for future building decarbonization, combined with greater energy efficiency and the cost savings that come with it. There are certainly implementation challenges that need to be carefully evaluated and considered, but the success thus far with our ongoing pilot projects in New York, as well as the potential for greater effectiveness in colder climates, remain encouraging for building owners throughout the U.S.

We helped launch TENS.NYC to provide a region-specific resource for TENs in urban dense environments to help inform potential participants and hopefully accelerate decarbonization in New York City.