Northfield Mountain pumped storage project. Image credit First Hydro

A new study has suggested there could be significant benefits for the US state of Massachusetts and the New England regional power grid by increasing the use of the Northfield Mountain pumped storage facility.

The economic study by international energy consulting firm Energyzt Advisors LLC found that Massachusetts electric ratepayers could save $220 million from 2022-30 – while eliminating 21,000 cars’ worth of carbon-dioxide emissions every year – through policies that increase use of the state’s biggest energy storage facility.

The report, which builds on two 2019 reports about the economic and environmental value of large-scale energy storage to maximize the benefits of Massachusetts’ multi-billion-dollar investment in offshore wind generation, was commissioned by FirstLight Power, owner-operator of the 1168MW Northfield Mountain facility, which is located on the Connecticut River in Erving and Northfield.

Last year, the University of Massachusetts at Lowell and the Massachusetts Department of Energy Resources/Levitan & Associates published landmark reports highlighting the critical value of large-scale energy storage – such as increased utilization of Northfield Mountain or the Bear Swamp pumped-storage facility on the Deerfield River in Florida and Rowe, Massachusetts  – in order to maximize the economic and environmental benefits of offshore wind projects being developed off Massachusetts and Rhode Island in the next decade.

By capturing surplus wind power during periods of peak generation and returning it to the electric grid when wholesale prices are highest, the UMass-Lowell and DOER/Levitan studies reported, Northfield Mountain and other energy-storage assets would deliver enormous environmental and economic benefits, while also improving reliability during times renewable energy is unavailable.

Energyzt, at FirstLight’s request, moved those two studies another major step forward by quantifying potential benefits of increase utilization of assets like Northfield Mountain and their cost-effectiveness, using Energy Exemplar’s authoritative PLEXOS market model and published projections by Independent System Operator-New England and the U.S. Energy Information Administration about future energy demand, prices, generation sources, energy efficiency, use of electric vehicles and heat pumps, and other market factors.

Energyzt noted that for several years, Northfield Mountain, which was constructed by predecessor companies of Eversource Energy and opened in 1972, has been operated at less than 30% of its capacity. That reason for that underutilization is that its carbon-reduction benefits are not priced into the New England wholesale market system.

The comprehensive modeling exercise showed that if two of Northfield Mountain’s four hydroelectric units were contracted at market-competitive prices to operate for 5 hours a day during periods of highest-price electricity, they would:

  • Reduce electric costs for Massachusetts ratepayers by $220 million from 2022 to 2030.
  • Remove more than 875,000 metric tonnes of CO2 emissions during that time, the equivalent according to US Environmental Protection Agency calculators of taking 21,000 cars off the road or precluding the burning of 4,817 rail cars’ worth of coal.
  • Achieve as much C02 reduction as the entire Massachusetts Clean Peak Standard program is projected to deliver, and at far lower cost.

“Northfield operations can shave peak prices and reduce carbon emissions, resulting in a net benefit that effectively pays for itself,’’ the report states. “If Northfield were operated with the objective of reducing carbon emissions or cost to load, Massachusetts state environmental objectives could be realized at a competitive cost for Massachusetts residents” with “significant carbon emissions reductions at a reduced cost to load.”