Texas came uncomfortably close to another round of continuous blackouts past night because network operators misjudged the weather.
The Texas Electrical Reliability Council, which manages most of the state’s grid, had anticipated a soft cold front that would sweep across the state and reduce energy demand. It did not happen. As a result, demand on the grid was approximately 3,000 megawatts higher than anticipated, or the equivalent of 600,000 homes.
The forecast error, given that 25 percent of power generation was offline for seasonal repairs, was another grim reminder of the vulnerability of the Texas grid. Two months ago, a severe winter frost wiped out nearly half of the state’s generating capacity, leaving millions of people in the dark for days. But the weather on Tuesday was not extreme, and the shutdown has raised questions about whether the grid operator, known as Ercot, can prevent a repeat of February’s energy crisis.
“It’s a shame for a power grid in modern times to struggle to keep the lights on during a mild day,” said Daniel Cohan, associate professor of environmental engineering at Rice University. “We will be in trouble when a summer heatwave hits and demand is one and a half times higher than yesterday.”
Weather generally doesn’t have a big impact on electricity demand in spring and fall. Those are the so-called in-between seasons when customers are not turning on their heaters or turning off their air conditioners. On Tuesday, temperatures in Dallas, Brownsville and Houston were moderately higher than normal, reaching or exceeding 80 degrees Fahrenheit (27 degrees Celsius). That, combined with the shortage of generations, led Ercot to request conservation efforts for nearly four hours.
Next weekend may become another test for network operators. Temperatures are projected to dip to 40s in Dallas, Fort Worth and Austin and to drop to 50s in Houston and San Antonio. While it’s not the cold readings that triggered the Texas winter meltdown in February, that could boost demand for heating that is primarily powered by electricity in the state. “That’s cold for them by the end of April and could invoke a bit of heat demand overnight,” Rogers commented.