SAN ANTONIO — The Electric Reliability Council of Texas (ERCOT) relied heavily on emergency supplies to avoid rolling blackouts Monday, as Texans again approached a record for electricity demand.
To stabilize the strained grid, ERCOT employed a rare combination of tools for an unusually long time. The council also asked Texans to conserve power for seven hours Monday.
Still, there was almost no buffer between supply and demand during the afternoon. Spare electricity became so scarce that the commodity's market value reached its cap of $5,000 per megawatt hour.
"In recent history, this one is up there in terms of severity," said Doug Lewin, president of the Stoic Energy consulting firm.
Poor weather conditions Monday hampered renewable energy production, which has spared Texas from power deficits throughout the summer. Clouds covered solar panels in the western part of the state during periods of mild wind on the coast.
But Lewin called unexpected outages at coal and gas-fired plants the grid's "number-one issue" Monday.
In its appeal for conservation, ERCOT indicated fossil-fuel and nuclear generators would produce about 84 percent of their maximum capacity Monday.
Federal data indicates all four of Texas's nuclear plants would at full power Monday, meaning ERCOT projected fossil-fuel plants would underperform by 13,000 megawatts. One megawatt can power roughly 200 Texas homes on a hot summer day.
"There's a lot of thermal power plants out and we're not getting any explanation from the public utility commission about why that's happening," he said.
Those producers could be experiencing problems because they delayed routine maintenance in May, when the state asked generators to stay online to accommodate an early heat wave.
Lewin emphasized that some plants are currently operating at record levels during record heat, using equipment in need of tender, loving care.
"Things tend to break down more when it's 100 degrees outside," Lewin said. "Your car is more likely to break down. Your air conditioning is more likely to break down. Your power plants are more likely to break down."
"August is extremely concerning," he added.
Texans are already paying high electricity bills, largely due to high natural gas prices. Consistent, record-breaking demand will eventually prompt higher charges.
"The higher, on average, that wholesale market prices are - generally that does eventually make it down to rates," said Dr. Joshua Rhodes, an energy researcher at the University of Texas.
"It's going to stay hot and energy use is going to stay elevated," he added. "We haven't even hit August."