New York - Mayor Mamdani, Governor Hochul and the Metropolitan Transportation Authority (MTA) announced today a partnership to study a Thermal Energy Network (TEN) in the Brooklyn Bridge-City Hall 4/5/6 and Chambers Street J/Z station complex. The project will explore how to combat extreme heat on subway platforms while capturing and recycling excess heat to warm nearby municipal buildings during the winter.
The project would be the first thermal energy network installed in a U.S. transit system. The announcement comes days after Governor Hochul and the MTA announced plans for a comprehensive renewal project at the Chambers Street station, which is among the oldest in the subway system.
Brooklyn Bridge-City Hall 4/5/6 is one of the hottest stations in the subway system, with average temperatures reaching 96 Fahrenheit during the summer months, in 2025. While the MTA prioritizes reliable service in the short-term to get customers on air-conditioned trains and spend less time on platforms, this study will help identify ways to reduce heat, improve rider comfort, and mitigate heat-related issues that can lead to service delays.
The revitalization of Chambers Street J/Z, which will rebuild structures, replace tiles, upgrade stairways and restore the station from top to bottom, is being funded through congestion pricing. The project provides the MTA 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.
"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 Mayor 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."
"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 Governor Hochul. "Working with Mayor 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."
"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 Governor 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."
"Every time New Yorkers are stuck on a hot subway platform, we are confronted with the reality of the climate crisis," said Chief Climate Officer Louise Yeung. "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 City of New York is meeting the realities of climate change head-on by investing in infrastructure that is both resilient and innovative," said Department of Citywide Administrative Services Commissioner Yume Kitasei. "DCAS is proud to partner on this study to identify the next generation of upgrades that will make our public buildings and infrastructure more efficient, sustainable, and prepared for the future."
TENs, already in use at several hospitals and universities, move heat between buildings, significantly reducing reliance on fossil fuels. The MTA and City will 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 proposed geothermal network would capture, store and redirect excess heat that accumulates in the Brooklyn Bridge-City Hall and Chambers Street station complex to municipal buildings. Radiant cooling technology would absorb heat from Brooklyn Bridge-City Hall platforms, and potentially Chamber 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 to heat nearby municipal buildings.
The study will be conducted in partnership with New York City Department of City Administrative Services (DCAS), 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 is expected to 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.
The Chambers Street station is particularly well suited for the study because its abandoned center platform would allow the MTA 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.
"Every New Yorker who has spent even two minutes waiting on a sweltering subway platform knows how urgently we need better solutions to extreme heat underground," said City Comptroller Mark Levine. "This study will explore whether we can make stations more comfortable while capturing that heat for a productive use. I'm glad to see the Mayor and Governor working together to pursue innovative solutions that can simultaneously improve the experience of subway riders and build a greener, more efficient and lower-cost energy system."
"As climate change only continues to increase the frequency and severity of extreme heat waves, this study offers a creative solution for cooling, boosting our energy efficiency, and strengthening our city's climate resilience," said NYC Public Advocate Jumaane D. Williams. "It's especially exciting that this new technology will be explored at one of the city's hottest subway stations, bringing relief to riders who need it the most. I thank the MTA, MOCEJ and DCAS for their leadership in addressing one of our most persistent transit challenges to ensure the safety and accessibility of our subway system for all New Yorkers."
"Every Manhattanite knows the Chambers J/Z station needs serious work - and I'm elated Governor Hochul, Mayor Mamdani and the MTA are stepping up and getting to work," said Manhattan Borough President Brad Hoylman-Sigal. "The goal of this innovative study will be to capture excess subway heat and store it to heat the buildings above, providing a first-in-the-nation model for cooler, more comfortable subway stations, especially in the humid summer months. I'm grateful to Governor Hochul, Mayor Mamdani and NYSERDA for fostering and expanding upon an already-productive City-State partnership, which will deliver a far better ride for millions of New Yorkers."
"I am glad to see that the city and state government and the MTA are joining forces to study how to use thermal energy networks to bring down heat levels in our subway system. Every New Yorker knows the feeling when you go to take the train on a hot summer day and find yourself waiting on a stuffy, overheated subway platform," said New York State Senator Liz Krueger. "As climate change continues to increase temperatures in our city and across the world, it is more essential than ever that we work together to find solutions which can mitigate overheating and prevent an inconvenience from turning into a potentially life-threatening situation, while generating renewable energy in the process."
"Every summer, I hear from my constituents about how brutal the heat on subway platforms across my district and the City can be," said State Senator Brian Kavanagh. "As we face the growing dangers of climate change and prolonged extreme heat, exploring sustainable solutions to the high temperatures in our transit system is a critical task. I'm thrilled that the MTA is working to turn this harmful summer heat into a resource, joining SUNY campuses across the state and innovators across the world working with thermal energy networks to cut costs, provide effective heating and cooling, and reduce emissions. This study is exactly the kind of practical, climate-smart infrastructure that New York should be leading on, and I thank Mayor Zohran Mamdani, Janno Lieber and Jamie Torres-Springer, Doreen Harris, and everyone at the Mayor's Office, the MTA, NYSERDA and DCAS for their commitment to this important work."
"Anyone who has waited for a train at a subway station on a hot day knows how unbearable it can get," said Assemblymember Grace Lee. "As extreme heat becomes more common, we need innovative ways to adapt our century-old transit system. I am proud that Lower Manhattan is leading the way in testing a solution that could make stations more comfortable and our city more climate resilient. Thank you to Mayor Mamdani, MTA Chair Lieber and our partners at the MTA and City for investing in innovative solutions for New Yorkers."
"Many subway stations are more than a century old and weren't designed to handle today's extreme heat, making creative solutions essential," said MTA Construction & Development President Jamie Torres-Springer. "Exploring a Thermal Energy Network model is a major step forward that has the potential to turn excess heat into a valuable asset for riders and the city."
The partnership with the MTA builds on the Mamdani administration's efforts to confront the climate crisis and build a greener, more resilient city. Earlier this year, the administration released its Urban Forest Plan , plotting a course toward 30% tree coverage citywide. As temperatures rise, expanded tree canopy will help reduce heat and protect New Yorkers for years to come.
The administration is also making historic investments in renewable energy, including the construction of 130 solar installations on schools across New York City that will provide 27.5 megawatts of electricity. An additional 86 projects are in the pipeline and would add another 17.2 megawatts.
As part of the administration's mission to reduce citywide emissions, the City is also accelerating vehicle electrification. The administration has already surpassed 1,000 electric vehicles for law enforcement and is on track to fully electrify the Sanitation Department, Parks Department and DCAS enforcement fleets by 2030 - five years ahead of the timeline required by local law.
