BOSTON — New England’s energy grid has contended with its “most challenging operating conditions since the winter of 2017/2018” over the last two weeks, but officials at ISO New England said they expect conditions will progressively improve as long as power generators can replenish their fuel supplies.
While persistent cold weather fueled a surge in electricity demand and stressed natural gas supplies here, the regional grid operator has been operating since Jan. 25 under an emergency order from the U.S. energy secretary allowing it to tap into the maximum output of certain power generation sources to prevent blackouts, even if it means temporarily exceeding emissions limits or other restrictions.
In an update published Tuesday afternoon, ISO-NE said the grid “has performed well” since then and noted that its three-week forecast projects continued improvements.
“The region is not out of the woods yet, with another cold front expected this weekend into next week. Early forecasts also show below-normal temperatures throughout the month of February. The continued cold weather makes fuel replenishment critical to maintaining system reliability in the coming weeks,” ISO-NE said.
As of 9:30 a.m. Wednesday, demand on the grid was running slightly higher than projected. ISO-NE registered demand for 16,666 megawatts of power compared to a forecast of 16,540 MW. Wednesday’s forecasted peak demand is 18,360 MW and ISO-NE said it expects to have 23,835 MW of available capacity.
As the Jan. 25-26 snowstorm approached, the New England grid began relying more heavily on dirty fuels like oil than usual. As extreme cold set in, oil jumped from being used to generate 0% of the grid’s energy as of late on Jan. 22 to overtaking natural gas as the predominant generation source for the New England grid at about 40% of the total from Jan. 24 and into Jan. 26.
Oil is generally a small part of the New England grid’s resource mix and ISO-NE said the region’s natural gas system is “contracted primarily to serve home and business heating needs first.” So when demand for natural gas for home heating is elevated, as it has been during this cold stretch, the price of gas climbs as well. When natural gas is a more expensive option, some power generators elect to switch to burning cheaper oil.
Since it sought an extension of the emergency order through Feb. 14, ISO-NE has been stressing that grid reliability depends on the ability for power generators to replenish their supplies of fuel oil and liquefied natural gas. Last week, the organization said replenishment of LNG “has been strong” but that fuel oil supplies chains were still under strain from the storm.
The most recently-published 21-day forecast published by ISO-NE showed that the inventory of usable fuel oil at New England power generators that use it for their primary or secondary fuel had declined from 43% of its maximum amount in mid-January to 21% as of this week, the lowest level in at least a year.
The choice to switch to oil leads to greater carbon emissions into the atmosphere, running counter to the state’s mid-century net-zero emissions mandate.
“The ISO did not make these requests lightly and recognizes the importance of environmental permit limits,” the grid operator said in its update. “However, the prolonged nature of this cold weather made the initial request and subsequent extension necessary to ensure adequate generating resources are at hand to keep power flowing in the region.”
The ISO-NE grid resource mix has begun to normalize again. As of 9:30 a.m. Wednesday, the power on New England’s grid came mostly from natural gas (45%), followed by nuclear (20%), imports (14%), oil (10%) and renewables (7%). The renewables categories broke down as 38% wind, 27% wood burning, 20% refuse burning, 14% solar and 2% landfill gas, according to the grid operator.
ISO-NE said carbon dioxide emissions from the grid totaled 81.54 metric tons per minute as of about 9:30 a.m. Wednesday. Natural gas was the top emitter, accounting for 60% of those emissions. Next on the list was oil (26% of emissions) and wood-burning (8%), according to ISO-NE data.
During a frigid stretch between Christmas 2017 and Jan. 9, 2018, Massachusetts power generators burned two million barrels of oil – more than twice the amount of oil they burned during all of 2016 – in order to produce sufficient electricity, Energy and Environment Secretary Matthew Beaton told lawmakers in 2018.
“Economically, this is a disaster for us in New England. Equally as important, environmentally the emissions and the profiles of what occurred in this timeframe is nothing but a disaster,” Beaton said at the time.