Mamdani pitches subway heat plan for city buildings

New York’s subway heat plan took center stage Monday as Mayor Zohran Mamdani and MTA chief Janno Lieber unveiled a study that could turn miserable Lower Manhattan platforms into a source of heat for nearby city buildings. The proposal would examine whether excess heat from the Brooklyn Bridge-City Hall and Chambers Street stations can be captured, shifted and reused instead of simply baking riders underground.

The city and the MTA plan a joint feasibility study for a thermal energy network, or TEN, that would cool the station area in summer and move that heat to municipal buildings in winter. Officials said the possible recipients include City Hall, the David Dinkins municipal building, Tweed Courthouse and Surrogate’s Court. Mamdani, speaking at the Chambers Street station, said anyone who waits on a subway platform in August knows how hot the stations can become, and he joked about wearing a wool suit in the heat. Lieber said the average temperature there peaked at 96 degrees last summer and described the sites as among the hottest in the system.

The idea centers on geothermal technology that captures heat, stores it and redirects it through pipes and pumps. Officials said the plan would use radiant cooling to pull heat from the platforms and send it to geothermal boreholes drilled beneath an abandoned Chambers Street platform. Those boreholes would extend 500 to 600 feet underground. Mamdani said the system would move heat from below the city surface to warm offices where municipal employees work in the winter.

For New Yorkers, the pitch is straightforward: make uncomfortable transit spaces more bearable while cutting waste and reusing energy already trapped underground. Lieber said the technology has not been tested before in a U.S. transit system, though he pointed to its use elsewhere in the city, including at St. Patrick’s Cathedral. He framed the effort as a practical win for both riders and the city.