US Power Grids Aren’t Good at Forecasting Cold. That’s a Big Problem

The deadly winter storm that pushed power grids in much of the US to near their limit revealed an uncomfortable fact about the US energy system.

PJM Interconnection underestimated its peak demand by more than 9 gigawatts, or enough power to supply 9 million households in a region that spans from Chicago to Washington. The Electric Reliability Council of Texas saw its expected winter peak forecast shattered by energy use on Thursday, with electricity demand coming in at 6.5 gigawatts above expectations. Operators missed estimates by 10%.

The forecast miss exposes another layer of vulnerability at a time when the power network is aging and undergoing a massive transition. Forecasting by grid operators can leave Americans without power and pay high prices during extreme weather.

Oliver Kerr is the head of US power market analysis for Aurora Energy Research.

The winter storm exposed deep flaws in the US energy system.

Kerr said that power grid operators need to get better at anticipating extreme winter events because they will become more common. He said that there is less historical information available for electricity use during cold weather.

More than 6 million households and businesses lost power during the winter storm according to Power Outage.us.

There are very few examples of the impact of cold weather on electric demand, according to Ercot.

The timing of the storm at the beginning of the holiday period added to the complexity.