New England, the region leading the way in energy efficiency and adoption of renewable sources, nevertheless faces the likelihood of rolling blackouts by winter 2024-2025 if fuel constraints to its power system are not resolved.

ISO New England, operator of the region’s six-state power system, developed 23 scenarios in its recently released “Operational Fuel-Security Analysis” to depict a wide range of possible power system conditions in the mid-2020s. Load shedding—rolling blackouts or controlled outages that affect blocks of customers sequentially—were projected in 19 of those scenarios.

ISO did not offer recommendations but noted that it would discuss the study’s results with regulators, policymakers and stakeholders throughout 2018 to find a way forward.

“A key question to be addressed will be the level of fuel-security risk the ISO, the region and its policymakers and regulators would be willing to tolerate,” said the study.

At its heart, the study examines the result of the region’s greater reliance on natural gas for power generation. ISO considered five key variables:

  • Coal- and oil-fired power generators and nuclear plants: These facilities, which have fuel stored on site and are essential for system reliability when natural gas is not available, will retire between now and the mid-2020s;
  • LNG: Most of these imports are from Trinidad and Tobago and are typically contracted months in advance of winter—in a cold snap, arrival of a tanker is at least five days away (weather allowing);
  • Dual-fuel generators: Many are retiring, and building new facilities that can run on both oil and gas presents problems—tighter state emissions requirements would limit the time that generators could run on oil and obtaining permits to build new plants has become more difficult;
  • Imports of electricity: Winter demand that places a stress on neighboring power systems could put additional supplies to the region in doubt; and
  • Renewable resources: Growth in wind and solar power generation is likely to drive retirements of most costly, aging coal- and oil-fired plants but higher imports of LNG will be needed to counteract the loss of stored fuels.

Increased usage of natural gas is being met with an expanded natural gas supply infrastructure, but the amount of infrastructure is not increasing at the same pace, hence the winter supply constraints.

“When pipeline supply constraints occur, all or almost all the available natural gas goes to heating customers,” said the study. When those power plants can secure the gas they need, the region relies on coal, oil, nuclear power plants and imports from neighboring power systems with adequate infrastructure.

However, more than 10% of the region’s generators that use fuels other than natural gas are expected to retire by 2021. Renewable resources, backed by state and federal financial incentives, offer low costs but the lack of storage capability presents its own challenges during peak winter demand after sundown. Onshore wind facilities, for the most part, are proposed for remote areas of northern New England and are not designed to carry large amounts of generation that is needed in southern New England.

How bad could it get? Assuming a severe winter in 2024-2025, the region could be exposed to rolling blackouts for as much as 14 hours spread over six days in the reference case. Even the maximum available supply of 1 billion cubic feet per day of LNG would not preclude those six days of load shedding.

The New England power system is acutely vulnerable to the loss of any one of several energy facilities, the study said. And the risks are increasing.

“Current trends,” the study said, “are pushing the New England power system on a path toward greater fuel-security risks.”

Joseph Markman can be reached at jmarkman@hartenergy.com and @JHMarkman.