The Metropolitan Transportation Authority (MTA) unveiled a new partnership to study a Thermal Energy Network (TEN) in the Brooklyn Bridge-City Hall 4/5/6 and Chambers Street J/Z station complex to combat rising platform temperatures. The project is designed to explore how to handle extreme heat on subway platforms while capturing and recycling excess heat to warm nearby municipal buildings during the winter.

The MTA says that the project would be the first TEN installed in a U.S. transit system. The announcement comes days after the MTA revealed plans for a renewal project at the Chambers Street station, which is among the oldest in the subway system.

“For years, New Yorkers have suffered through sweltering summer heat on subway platforms, with seemingly no hope for a cooler ride in sight. Today, I can assure riders during this hot summer week that help is on the way," said Gov. Kathy Hochul. "Working with Mayor [Zohran] Mamdani and the MTA, we are harnessing cutting-edge climate technology for a truly cool purpose: making our subway stations tolerable during the summer and heating critical city buildings during the winter. This is what effective partnership between city and state government can yield—innovative solutions that have the potential to help millions of subway riders."

The MTA reports that the Brooklyn Bridge-City Hall 4/5/6 is one of the hottest stations in the subway system, with average temperatures reaching 96 degrees Fahrenheit in the summer months of 2025. While the authority notes it is prioritizing reliable service in the short-term to get riders on air-conditioned trains and spend less time on platforms, this study is designed to help identify ways to reduce heat, improve rider comfort and mitigate heat-related issues that can lead to service delays.

The rehabilitation of the Chambers Street J/Z station is set to bring needed repairs and improvements to the 113-year-old station. The MTA says the project provides it and city with a unique opportunity to study TENs as a tool to cool subway platforms while capturing and reusing excess heat in nearby municipal buildings during the winter, lowering energy costs over the long term while dealing with subway heat at the same time.

“There are few feelings worse than escaping the extreme summer heat only to find yourself on a subway platform that is even hotter. Unfortunately, for millions of commuters that is the reality of our transit system—with some stations soaring up to 20 degrees hotter than the outside temperatures,” said New York City Mayor Zohran Mamdani. “We now have an opportunity to do more than rebuild Chambers Street top to bottom. We can make our subway platforms cooler and more comfortable while putting wasted heat to work during the winter. That means lower energy costs, a more resilient subway system and a cleaner energy future for New York City.”

TENs, already in use at several hospitals and universities, move heat between buildings, reducing reliance on fossil fuels. The MTA and city are set to assess the feasibility of using TENs and geothermal infrastructure to absorb, store and transport excess heat between subway stations and adjacent municipal buildings.

The initial feasibility study will help determine how much cooling can be achieved and the potential energy cost savings for the city. The study is projected to cost $800,000.

Radiant cooling technology would absorb heat from Brooklyn Bridge-City Hall platforms and potentially Chambers Street as well and transfer it through pipes to geothermal boreholes drilled beneath the abandoned center platform at Chambers Street. The excess heat could then be stored in the boreholes and used during colder months.

The study will be conducted in partnership with New York City Department of City Administrative Services, the Mayor’s Office of Climate and Environmental Justice, the Office of the Deputy Mayor for Operations and the MTA. The contract for the feasibility study will be awarded this fall. Pending confirmation of geothermal feasibility, design work will begin in early 2027.

This initiative is part of the city and MTA’s broader efforts to address the threat climate change poses to the future of the transit system, including the growing impacts of extreme heat. Radiant cooling, which can be 25 to 35% more energy efficient than traditional air conditioning, removes heat by circulating chilled water through panels on walls and ceiling or through tubing embedded in the floors, allowing cool surfaces to absorb heat directly.

“Every time New Yorkers are stuck on a hot subway platform, we are confronted with the reality of the climate crisis,” said New York City Chief Climate Officer Louise Young. “Advancing a thermal energy network that will sustainably cool the Chambers Street subway station and heat the surrounding city buildings is a testament to our administration’s bold and innovative agenda to deliver climate solutions that protect New Yorkers. From advancing the nation’s first subway thermal energy network to piloting heat-resilient bus shelters and outdoor cooling centers, the city is committed to making our transit systems safer and more comfortable as New York City faces rising temperatures.”

The MTA says the Chambers Street station is particularly well suited for the study because its abandoned center platform would allow the authority to test technology without disrupting passenger areas. Brooklyn Bridge–City Hall also experiences significant heat in part because of heat generated by trains dwelling at the 6 line terminal.

“Bringing down the temperature is a real challenge in a century-old system with open entrances and vents everywhere,” said MTA Chair and CEO Janno Lieber. “Together with Gov. Hochul and Mayor Mamdani, we’re exploring solutions—previously untested in transit—to make stations more comfortable while helping to reduce energy costs. Everybody wins.”