The Metropolitan Transportation Authority (MTA) and Council Member Zohran Mamdani are evaluating high-tech options for transferring heat from subway stations to above-ground buildings. This infrastructure project is expected to be elaborate and costly. Nevertheless, city representatives and the MTA are convinced that the investment could be worthwhile to provide commuters with a more comfortable experience on the platforms. The heat generated is intended to be used to reduce the energy consumption of commercial and residential buildings above ground.
Janno Lieber, Chair and CEO of the MTA, explained during a press conference at Chambers Street Station that numerous options for improving comfort in the stations are being investigated. They are examining innovative energy networks, known as TENs, and geothermal concepts. These would make it possible to capture, store, and then transfer excess heat in subway stations for use in heating the buildings above them in winter.
Technological Approaches and Potential Challenges
Although this technology has never before been applied in conjunction with a transport system, some buildings in New York City already use geothermal energy from underground. Examples include St. Patrick’s Cathedral in Midtown and 555 Greenwich Street in Hudson Square. According to Lieber, the technology is widespread in Canada and Europe, and proptech companies have been presenting geothermal piles as building infrastructure for several years now.
It is unclear what the technology would look like exactly on a large scale or how many buildings it could serve. City officials, such as New York City Comptroller Mark Levine, expect that coordination between the city, state, and private stakeholders could become complex. A possible expansion would be the use of heat from refrigerators in grocery stores and small data centres distributed throughout the five boroughs.
On Monday, Council Member Mamdani mentioned several city buildings that would be eligible, including City Hall, the David N. Dinkins Municipal Building, and the Tweed Courthouse. He explained that heat would be captured in boreholes extending 500 to 600 feet underground, and a system of circulation pumps and pipes would be installed. This system would utilise the underground heat to warm offices where city employees work.
One aspect that, according to Lieber, is not an option for cooling the stations is air conditioning. The stations are not fully enclosed by street entrances, ventilation shafts, or grates, meaning that the cool air would escape into the tunnels.
