Battery Energy Storage System (BESS)

On November 7, 2024, Wellesley flipped the switch on a new battery energy storage system (BESS) project that will significantly help our community meet rigorous climate action goals set by Town officials and the Commonwealth. 

The Wellesley Municipal Light Plant (WMLP) is partnering with Citizens Energy, a nonprofit energy corporation,on the BESS project. Located adjacent to a WMLP substation, the BESS is a 4.99 megawatt system that will provide electricity cost savings to residents during peak demand periods and provide emergency backup power to essential Town services in the event of a power outage.

The BESS has six 20-foot battery containers and six inverter containers. It has the capacity to charge and store more than 20 megawatt-hours of energy during low-cost periods of low energy demand and discharge that energy during higher-cost periods of peak energy demand.

Over a twenty-year period, this project is expected to yield more than $8 million in savings for WMLP ratepayers by reducing reliance on expensive peak power. By reducing the Town's peak demand that would otherwise be supplied from fossil fuel based generation, this project also directly aligns with Wellesley's Climate Action Plan goal to achieve net zero greenhouse gas emissions by 2050.