Power Plant Retirements

With the transition to a power system made up of more resources with limited energy inventories (natural gas, wind, solar, battery storage), the region is losing traditional generators that have substantial on-site fuels (nuclear, oil, or coal) and can sustain extended operations during cold weather conditions for days and even weeks on end. Since 2013, more than 7,000 MW of mostly coal, oil, and nuclear generation have retired or have announced plans for retirements in the coming years.


See Status of Nonprice Retirement Requests and Retirement De-List Bids for the most current list of future and historical resource retirements in New England.

The Economics of Retirement

Several factors are challenging coal-fired, oil-fired, and nuclear power generators’ ability to recover the cost of capital investments to maintain their older plants.

  • Fuel and environmental-mitigation costs make them too expensive to effectively compete against:
      • Newer, faster natural-gas-fired generators that typically have lower fuel costs and use less fuel
      • Growing levels of renewable-energy resources that have no fuel costs, low operational costs, and government incentives designed to lower their initial capital investments
  • These older oil and coal plants can require up to 24 hours to reach full power production, making it difficult for ISO operators to rely on them when system conditions are tight. Their age and lack of regular operation can also sometimes lead to mechanical problems.
  • Oil-fired power plants tend to keep limited fuel supplies on site to avoid the expense of purchasing oil that they may not use. So, even when called to run, they often can’t run for very long.
  • Low wholesale electricity prices over recent years, largely a result of typically low natural gas prices, have also reduced revenues for these resources when they run.

For many, the only option is to retire. These resources are likely to be replaced by intermittent clean energy resources.

Generators closed or retiring in New England

Retirement of Resources with On-Site Fuel that Can Sustain Operation during Cold Weather

On days when natural-gas-fired generators have unconstrained access to low-cost pipeline gas, they usually produce the majority of New England’s electricity. However, natural gas delivery constraints in winter caused by high demand for this fuel from both the heating and electric power sectors can prevent these resources from filling this need during cold weather. Wind output is also especially variable during winter. During the 2017–2018 cold spell, ISO system operators observed variable generation from wind turbines, as wind speeds fluctuated throughout the 16-day period. At times, transmission congestion also required curtailments of some wind farms.

Very few coal plants remain and oil-fired plants, which typically don’t run often, become critical on cold winter days when the fuel for natural-gas-fired generators is limited and expensive.

Oil Generation if High During Extreme Winter Cold

Nuclear power supplied 20% of the grid electricity New Englanders used in 2023, and our analyses show that the region would be more vulnerable to controlled outages, higher prices, and increased emissions should we lose New England’s two remaining nuclear stations. Regional emissions rose when Vermont Yankee closed in 2014, for example. The remaining nuclear facilities (Millstone and Seabrook, which have a combined capacity of 3,300 MW) will be critical components of the hybrid grid because they are carbon-free and have a dependable, on-site fuel supply, but how they can remain financially viable is still unclear.