ERCOT admits Texas grid faces risk of ‘cascading outages’

From the San Antonio-Express News

The state grid operator is admitting it underestimated how quickly the San Antonio region would grow — a missed forecast that’s left it with transmission issues that “could lead to cascading outages” that put the statewide grid at risk.

The Electric Reliability Council of Texas this week told regulators its analysis missed the need to boost transmission capacity between the southern and northern regions of the state. While CPS Energy has a new line in the works to solve the problem, it won’t be done for three more years.

“We should have been able to see this in 2018,” Chief Operating Officer Woody Rickerson told the Public Utility Commission on Thursday. “If we saw it in 2018, we’d have time for this line to have been built last year.”

Now, ERCOT is preparing to cut off power to keep it from overcrowding lines when demand is high and power supply is uneven between the south and north ends of the existing lines. The action, which would curtail about 250 megawatts systemwide, aims to head off emergency conditions like those reached Sept. 6, when the state grid came closer to blackouts than it’s been since the February 2021 winter storm that left millions of people in the dark for days and more than 200 dead.

Commissioners weren’t thrilled with the idea of keeping power off the market. Rickerson said he wasn’t, either, but that in certain situations, it’s the best option to stave off a more dire scenario.

When there are outages or lower supply from renewables on one end of the line — typically the end opposite San Antonio toward Waco and Dallas — the path to move the extra supply to where it’s needed can become like a crowded highway of speeding cars. The more cars, the more potential for crashes.

Northern deficit

“I know y’all are trying to do what’s right for reliability across the system,” Commissioner Jimmy Glotfelty said. “The way that I think about this from a generator perspective … that when you put the limit on this line, you’re effectively limiting generation in the south’s ability to get to the market in the north.”

Rickerson said the issue comes from the fact there is not enough generation north of the pain point. Meanwhile, there’s sometimes a surplus of power at the opposite end — from CPS Energy or wind farms in Corpus Christi.

He said load growth — the actual amount of power needed — was much “more rapid and concentrated” in San Antonio, the whole of Central Texas, and Dallas than ERCOT anticipated.

“That made the situation worse,” Rickerson said.

Rapid increases in demand for power are being driven by the state’s population boom, hotter temperatures and business growth — including power-hungry data centers and crypto mines.

Another factor in ERCOT’s missed forecast: After 2018, some 6,400 megawatts of generation capacity in northern parts of the state was closed and retired — more than it had expected. In the same period, the southern part of the state rapidly added upward of 4,000 megawatts of wind and solar generation.

Solar, wind and battery storage systems can be constructed more quickly and at less expense than traditional gas-fired power plants. While the time it takes to get new power online has decreased, beefing up transmission lines to handle that power still takes between three and five years.