A 42-megawatt boiler is delivered to Vicinity Energy's Kendall Square plant in November 2023. The electrically-fired boiler will be used to help produce carbon-neutral steam to help heat and cool buildings in downtown Boston. Photo courtesy of Vicinity Energy

Decarbonization of a 75-year-old Kendall Square power plant passed a milestone this week with delivery of an electric boiler that will replace gas-fired turbines to heat buildings in Boston and Cambridge.

The 42-megawatt boiler is part of Vicinity Energy’s eSteam product, which uses a network of underground pipes to deliver heat to buildings.

The electric boiler is scheduled to begin operation in spring 2024. The second phase of the decarbonization project, installation of a 35 megawatt electric heat pump complex, is scheduled for completion in 2027.

Boston-based Vicinity Energy is promoting its eSteam product as a way for commercial developers to meet carbon-reduction regulations such as Boston’s BERDO 2.0 building emissions limits. The 960,000-square-foot Fenway Center lab project, being built on Massachusetts Turnpike air rights parcels, signed the first contract to use the eSteam system in early 2023.

The Kendall Square plant was originally developed in 1948 by Cambridge Electric Light Co. as a coal-fired facility to power nearby factories.

Boston-based Vicinity Energy supplies thermal energy and electricity to approximately 70 million square feet of building space in Boston and Cambridge.