Eversource plans to replace underground lines in Hopkinton, Milford. Why the work's needed

Tom Benoit, The Milford Daily News
·3 min read

Eversource is proposing to replace a roughly one-mile stretch of underground electric lines between two substations — one in Milford and one in Hopkinton — in order to meet greater anticipated demand and to help it achieve state environmental goals.

Eversource is looking to replace a 1.3-mile stretch of transmission lines running between Purchase Street in Milford and South Street in Hopkinton; most of the work would occur in Milford. According to the utility company, the replacement not only modernizes the line, but will also make the system more reliable. The improvements would also align with the state's goal to achieve net zero carbon emission standards by 2050.

"We have proposed the Hopkinton to Milford Line Replacement Project as part of our Underground Cable Modernization Program, aimed at modernizing the cable infrastructure and increasing long-term system reliability in the face of climate change and to help facilitate the interconnection of more clean-energy resources," William Hinkle, Eversource's media relations manager, said in an emailed statement.

Eversources workers are shown in action on a transmission line construction project in Sudbury in March 2023. The utility is now proposing to replace a 1.3-mile stretch of underground electric lines between two substations, one in Hopkinton and the other in Milford.
Eversources workers are shown in action on a transmission line construction project in Sudbury in March 2023. The utility is now proposing to replace a 1.3-mile stretch of underground electric lines between two substations, one in Hopkinton and the other in Milford.

Existing transmission lines were installed 25 years ago

The lines slated for replacement run along Purchase Street in Milford, connecting the town's substation there with another on South Street in Hopkinton. Currently, Eversource operates the lines, which are 115-kilovolt (kV) high-pressure gas-filled (HPGF) electric transmission lines, and plans to replace them with modernized, cross-linked polyethylene 115-kV (XLPE) transmission lines.

Sudbury-Hudson project: Eversource begins construction of high-voltage transmission line

The existing transmission lines were installed in 1998 and are among the last remaining HPGS lines in Eversource's system.

Eversource has been holding public and virtual open houses, beginning in February and expected to continue for another few months.

The project is also required to be reviewed by the Energy Facilities Siting Board (EFSB), an independent state board that reviews proposed large energy facilities including power plants, electric transmission lines, intra-state natural gas pipelines and natural gas storage tanks. To obtain approval, the proposed project must demonstrate that, if approved, it would provide a reliable energy supply with a minimal impact on the environment at the lowest possible cost.

Eversource plans to submit its plans to the EFSB later this spring.

Transmission line replacement would include substation upgrades

The proposed replacement lines would follow the same or similar 1.3-mile stretch as the existing lines. According to Eversource's website, most of the work will be concentrated along Purchase Street in Milford and on a portion of South Street in Hopkinton. Eversource also plans to make minor equipment upgrades at the Hopkinton and Milford substations to accommodate the new infrastructure.

Eversource intends not to disrupt normal electric service.

The Hopkinton and Milford work is among other underground cable modernization projects in Massachusetts, including one between Boston and Everett and two projects in Springfield.

'A great place to be': Hopkinton's population jumped by 26% from 2010 to 2020

According to Eversource, the project is being done to anticipate future demand, with both Milford and Hopkinton seeing sizable recent population growth. During the 2020 census, Hopkinton experienced a roughly 26% increase in population, going from 14,925 residents in 2010 to 18,758 in 2020. Milford saw an 8% increase in residents, from 27,999 in 2010 to 30,379 in 2020.

"We’re working every day to upgrade and modernize our electric grid in order to meet the evolving energy needs of our customers, make the system more resilient to extreme weather caused by climate change, and help the Commonwealth achieve its decarbonization and electrification goals," Hinkle said. "Demand for electricity will only continue to increase in the future with continued economic development, as well as the push to electrify the heating and transportation sectors with more customers adopting technologies like heat pumps and electric vehicles."

If the plans are approved by the EFSB, construction would begin in the fall of 2025 and be completed in the spring of 2027.

This article originally appeared on MetroWest Daily News: Eversource to upgrade transmission line in Hopkinton and Milford