Holyoke Gas and Electric: Largest Utility-Scale Energy Storage Installation in Massachusetts
What the Judges Said…
“Storage has not usually been part of the grid management so this could be game changing. It’s an exceptional step being taken by Holyoke Gas and Electric that others can learn from and emulate.”
Engie company Green Charge and Holyoke Gas & Electric (HG&E) plan to install the largest utility-scale energy storage installation in Massachusetts. Green Charge designed and will operate the 3 MW/6 MWh-AC battery-based energy storage system at Mt. Tom Solar. The system will be used to optimize intermittent solar energy and reduce utility capacity costs for HG&E while reducing stress on the HG&E distribution system.
The partners expect this project to contribute to rate stabilization over 20 years, and for customers to benefit from improved power quality and reliability. Electricity produced from the Mt. Tom 5.76 MW-DC solar farm will be stored in the energy storage system isolated from but interconnected to HG&E’s electricity grid. This stored power will be called upon during local and regional peak load periods to cost-effectively satisfy demand while reducing utility costs and demand charges for customers. Demand charges are incurred for electricity and capacity taken from the power grid and used during peak demand periods.
Originally the plant ran on coal until 1971 and then was converted to oil. In 1981 it was converted from oil back to coal. The coal plant was shut down in 2014 and decommissioned. The location for the energy storage system is adjacent to the Mt. Tom Solar Farm, and located on the property. The project will take approximate 200 days complete. Steps include permitting, design, engineering, and construction. Construction covers concrete footings and steel pylons, wiring, and interconnecting the energy storage system with the solar array and power grid.
Other unique aspects of the energy storage system include keeping electric rates stable by reducing rising capacity charges for utilities and demand charges for consumers, increasing the power quality by maintaining nominal voltage and frequency values, increasing the use of clean energy sources, and reducing the peak load burden on an electrical distribution system that can, in turn, increase the useful life of the distribution assets.
HG&E can use the battery energy storage system to reduce its exposure to extreme peak energy prices. About 8% of the utility’s energy costs are from the top 1% of the hours of energy use, so by using the battery’s energy rather than the grid’s energy during those high-cost hours, the utility can save its end customers even more money, according to Green Charge. Massachusetts Governor Charlie Baker says the project will strengthen the state’s innovation economy and provide a roadmap for securing its energy future.