Boston to Transform City Heating Using the Charles River

The city of Boston is exploring ways to tap the Charles River's capacity to generate a low-carbon, low-cost heating source for the city.

Last November, Canary Media reported that Vicinity Energy is leading the transformation of Boston's century-old steam heating network. The company is currently replacing gas with electric boilers and large-scale heat pumps to extract warmth from the Charles River. This approach would allow Boston to  "heat millions of square feet of the city's buildings," according to a report by The Cool Down.

The project aims to decarbonize urban heating, reduce air pollution, and serve as a model for other cities. Completion is anticipated around mid-2028.

“That project was greenlit this summertime,” Vicinity Energy CEO Kevin Hagerty told Canary Media in 2025. “We're anticipating that being completed midway through 2028. We'll turn the heat pump on and turn the Charles River into a renewable energy resource.”

For customers in Cambridge and Boston, Vicinity's “eSteam” plan is a sensible idea, Hagerty said. According to Hagerty, Massachusetts has established regulations to expand its supply of carbon-free electricity and reduce its reliance on fossil fuels in buildings. 

Last year, according to Canary Media, Vicinity Energy completed the installation of a 42-megawatt electric boiler at its Kendall facility. Earlier this year, the company unveiled plans to install a 35-megawatt industrial heat pump from Everllence, a German energy systems manufacturer.

According to Hagerty, the industrial heat pump draws on the river water's latent thermal energy to raise temperatures to the boiling point within the Kendall facility's steam-generation complex. The technology can operate even during the winter months because the low-temperature refrigerant it uses is much colder than the ice-cold Charles. That contrast creates a temperature differential that the heat pump can use to produce steam.