New England is an established leader in America’s clean energy transition. Its member states have set some of the country’s most aggressive decarbonization targets, with five of six of its member states setting targets of 80% or more emissions reductions by 2050. Achieving these goals while meeting more immediate challenges posed by climate change will require building resources that can contribute to a sustainable electric grid in a reliable, safe, and affordable way.
The challenges to New England are twofold. First, the region requires clean, dispatchable resources that can balance its rapidly growing amount of intermittent renewables coming onto the grid. Such firm resources will be essential for meeting electricity demand when the output from wind and solar is less than expected for multiple hours and days. Second, the New England grid is particularly vulnerable to winter oil and gas supply shortages, as a result of pipeline transport limits coupled with competing fuel demand to keep homes and businesses warm. There is a near-term need in New England for resources that can reliably deliver energy during periods of high grid stress in the winters.
Energy storage technologies that capture and store energy during times of low demand and discharge when energy is most needed will be key to solving many of these challenges. Specifically, multi-day storage (MDS) is a promising class of energy storage technologies that can continuously discharge stored energy for several days, providing clean electricity when and where it is needed over much longer periods than existing short-duration technologies. Form Energy’s Software & Analytics team recently analyzed New England’s energy system using Formware, our grid modeling tool, to understand what mix of energy storage technologies could best meet the region’s decarbonization and winter reliability needs.
The findings from this analysis were recently published in a white paper, Clean, Reliable, Affordable: The Value of Multi-Day Storage in New England, which demonstrates that a diverse portfolio of clean energy resources that includes MDS brings substantial winter reliability benefits in the near-term, while also supporting the cost-effective and sustainable achievement of long-term decarbonization goals. Three of the study’s key findings were :
- Deploying 3 GW of MDS in New England by 2030 could avoid winter energy shortages at a cost that is 74% lower than with short-duration storage alone.
- Pairing sufficient MDS with offshore wind could create a source of firm, zero-carbon energy that would support grid reliability during all times of the year for 80% less cost than could be achieved with short-duration storage alone.
- Adding 23 GW of MDS to the region’s portfolio by 2050 would avoid the need to build nearly 150 GW of new resources – reducing costs of decarbonization by up to 33%, curbing renewable energy curtailment by 83%, and avoiding impacts to more than 300,000 acres of land.

Form Energy’s modeling indicates that MDS could play an essential role in enabling a reliable, affordable, decarbonized energy system in New England. But to realize these opportunities, the region must start deploying these resources as soon as possible. Near-term state policy support will be needed to build the market for these emerging technologies and smooth the transition to a fully decarbonized future. Policies that specifically seek to procure or incentivize development of multi-day storage solutions by 2030 will help expedite commercialization and make these promising new resources a reality for New England.
To learn more about these results and further findings from our analysis, please see the full whitepaper, “Clean, Reliable, Affordable: The Value of Multi-Day Storage in New England,” available at the link here.