Fortifying Energy Reliability
To address the increasing reliability risk, prevent extended power outages throughout Hingham, and meet current industry reliability standards, HMLP considered an extensive range of potential solutions, including several alternative tap points for a third transmission line to Hingham in surrounding towns in addition to Weymouth, conservation efforts, interruption of firm and non-firm load, wind resources, solar power paired with battery storage, and emergency generation.
After an exhaustive study of all potential solutions, the project team determined that the most effective, most cost efficient, and least environmentally intrusive solution is the construction of a new, underground 115 kV transmission line that will run from a new Eversource tap station off Broad Street in Weymouth, approximately 3.2 miles, to connect to a new Hobart II Substation to be located at the Hingham Transfer Station site off Old Hobart Street.
This new underground transmission line and new substation would be constructed, owned, and operated by HMLP. The new tap station in Weymouth would be owned and operated by Eversource.
The estimated length of the underground transmission line is 3.2 miles -- 2.1 miles in Weymouth and 1.1 miles in Hingham. The preferred route would travel underground from the new substation at the Hingham Transfer Station, run west on Hobart Street, turn south on French Street, then turn west on High Street and continue west into Weymouth, where it becomes Broad Street and Commercial Street. Broad Street will then be followed for approximately 9300 feet until the line ends at the proposed new Tap Station site at the Eversource transmission corridor in Weymouth.
With the new underground 115 kV transmission line and second substation in place, HMLP’s system will address its growing reliability challenges and be in conformance with industry reliability standards, protecting Hingham customers from the growing risk of extended outages.
Although it is not needed for capacity purposes at this time, in the longer term, the new transmission line will also support the Town of Hingham’s Climate Action Plan and State electrification goals. Consistent with these goals, HMLP has selected a substation site in Hingham that is large enough to accommodate an additional transformer, which can be added at a later date when HMLP’s load exceeds approximately 80 MW.
