Winter cold snap a case study for energy grid limitations

BOSTON — Fuel security is the biggest reliability risk factor for a New England energy grid that depends on a variety of fuel sources, a conclusion that was exemplified by the midwinter cold spell, a recent ISO New England study concluded.

The study, which began in 2016, modeled several hypothetical scenarios for the winter of 2024-25. The goal was to understand the risk of relying on different types of fuel to provide the region’s energy.

But when ISO New England CEO Gordon van Welie discussed the report in a recent briefing, he described a real scenario.

“That cold spell underscored some of the very real challenges to reliability posed by fuel-security risks,” van Welie said, referring to the low temperatures earlier this winter. “During the two weeks of Arctic cold, New England generators burned through about 2 million barrels of oil. That’s about 84 million gallons. That’s more than twice as much as all the oil used by New England power plants during the entire year of 2016.”

A little over 2 percent of the grid’s fuel source was from coal or oil in the early weeks of December 2017, according to van Welie. That went up to around 33 percent during the cold snap.

Part of van Welie’s concern is that the amount of oil burned in just the first week of 2018, the second week of the cold snap, pushed near the states’ emissions limits. If the region experiences another high energy use period — whether from extreme cold or heat — options to fuel the grid may be artificially limited. Van Welie said he hopes that states would waive the emissions limits for such a scenario.

“This illustrates something I said earlier — that coal and oil power plants rarely run most of the year, but they are still needed during extreme weather events. Nuclear power is also a key contributor,” he said.

In addition to uncertainty around energy demands due to weather, there is also uncertainty about what normal demand will look like in the future. According to van Welie, the adoption of some new technologies, such as electric vehicles, may result in an increase in demand for energy from the grid.

“Some New England states are pursuing policies to reduce carbon emissions from other sectors, which has the potential to reverse declining demand for electricity. As the use of fossil fuels for transportation and heating declines, more electricity will be needed to keep all those electric vehicles charged and heat pumps going.”

While use of renewable resources to fuel the grid is growing, the report found, sources like wind farms and solar panels are weather-dependent and the grid does not yet have sufficient storage or transmission infrastructure to rely on them during times of high energy demand.

“All these renewable and clean-energy resources are growing rapidly, but it will be many years before New England can rely on these sources for all its power needs,” said van Welie.