Cold-caused power grid problems start to level off

Power usage on the New England grid leveled off a bit Wednesday as temperatures began to slowly rise. But prices were still running high – more than $300 a megawatt hour at times – as the Independent System Operator that manages the grid, ISO New England, continued to use more expensive oil- and coal-fired generation.

Their use, beginning with the first cold snap late last week and again Tuesday, has been the result of the lack of gas lines in the region. They are at capacity so when the weather is cold, more of that gas goes for heating. That leaves less for power generation, so the ISO turns to coal and oil plants.

Coal and oil together typically account for less than 4 percent of the fuel mix the ISO has on the grid. On Wednesday, they again accounted for about 30 percent. Natural gas, usually more than 50 percent of the mix, was at less than 30 percent.

Peak demand today was predicted to be 21,060 megawatts. Yesterday’s peak demand had been predicted to hit 20,700 megawatts, but actual demand far exceeded that.