In a part of Cambridge where new lab towers seem to sprout every few months, the biggest new piece of infrastructure will be almost impossible to see. Engineers are assembling a 35,000-square-foot electrical substation roughly 105 feet below a future plaza between Broadway and Binney, built to feed the surging power needs of Kendall Square’s biotech and lab cluster and nearby Boston neighborhoods.
As reported by The Boston Globe, the underground facility is the result of a years-long negotiation among Eversource, developer BXP and city officials. Under the deal, BXP is building the below-grade space on its Kendall parcel, then selling it to the utility. In return, the city granted the developer extra entitlements that the Globe says include room for two roughly 400,000-square-foot commercial buildings and a tall residential tower, while Eversource agreed to sell a Fulkerson Street parcel in East Cambridge to the city as part of the swap.
How the system will work
According to Eversource, the Kendall Square substation will connect to five underground duct banks and eight new 115-kilovolt transmission lines serving parts of Cambridge, Somerville and Boston. One route calls for a horizontal directional drill beneath the Charles River from the Magazine Beach area, a crossing described in public siting filings.
Construction officially started in January 2025, and city documents show the broader program is scheduled to come online in phases beginning around 2029, with full completion targeted near 2031 (City of Cambridge). In other words, the digging and cable work are just getting started.
The political trade
City leaders and the redevelopment authority cast the arrangement as a tradeoff: instead of a hulking substation next to a school and sports field, Cambridge gets the equipment tucked out of sight while BXP gets more room to build, as The Boston Globe reported. The compromise cleared the way for BXP’s Life Sciences Center and a residential tower at 121 Broadway, a 439-unit building BXP lists in regulatory paperwork, along with new public open space at street level where a parking garage once stood (BXP filings).
Price tag and who pays
Eversource investor filing materials put the Greater Cambridge Energy Program at an estimated $1.84 billion, with about $1.38 billion for transmission work and $460 million for distribution. Those filings say costs will move through the usual regulatory process, so how and when customer bills are affected will depend on later rulings by state regulators. Company, city and developer representatives say sharing construction and land costs is what made a fully underground substation viable in such a dense, high-value neighborhood.
What to watch
For people who live or work in Kendall, this will feel less like a single project and more like a long-running backdrop. Crews will be installing duct banks, building underground vaults and shifting traffic for years, with periodic lane changes and some night work in the mix.
City and project teams are posting traffic-management plans, staging maps and open-house dates on municipal pages and in the project docket. Residents are being urged to watch for notices on river crossings, permit milestones and community meetings, which are tracked in state siting materials.
