Finding little interest, ERCOT going back to drawing board for a solution to South Texas chokepoint

From the San Antonio Express-News

It was seeking 500 megawatts for a new conservation program but got less than 10

The state power grid operator is seeking a solution — again — for congestion-prone transmission lines near San Antonio it blames for increasing the risk of statewide blackouts.

Pablo Vegas, CEO of the Electric Reliability Council of Texas, said Tuesday that his plan for a new conservation program failed to draw sufficient commitments to get the job done.

“The contract for capacity that was issued to support summer conditions resulted in a very low submission,” he told the ERCOT board. “It’s clear … we need to modify the approach for developing the next set of demand response capabilities in the ERCOT market.”

In an interview last month, Vegas said he was confident the program would attract enough big users to provide 500 megawatts of on-demand power savings. By the June 13 deadline, though, only three applications for less than 10 megawatts were received. Vegas said he plans to formally cancel requests for proposals later this week.

It’s the second time in recent history that an ERCOT bid for extra seasonal capacity has flopped. Last winter, ERCOT tried to encourage owners of shuttered coal-fired generating plants to reopen them to increase the grid’s supply in case of a winter freeze or storm. That programming also sought what ERCOT calls “demand response,” which asks big users — or a pool of customers under a utility — to cut their power use at times the grid is stressed.

The latest request was focused on seeking power savings, targeting industrial power users that could reduce their power load in the evening hours this summer. Come August, ERCOT faces a heightened risk of rolling outages — about 12%, according to its own modeling — after the sun goes down and while demand is still high in the hour around 8 p.m.

Supply becomes tight in the early evening when demand is still high but the surplus of solar power that carries Texans through the daytime drops fast at sunset.

Adding to the problem is the South Texas transmission line near San Antonio, which runs the risk of getting overcrowded as plentiful power from South Texas wind farms and batteries is needed in North Texas, where capacity hasn’t kept up with increasing demand. This summer’s demand response plan was intended to mitigate those risks by removing local demand from the grid near the chokepoint.

A permanent solution is still at least two years away, as CPS Energy works on construction to grow the lines’ capacity.

Dan Woodfin, ERCOT’s vice president of system operations, said line congestion can keep the grid operator from accessing all available generation even when the market demands it. That’s what happened last September, when the San Antonio lines got overloaded and put the grid closer to rolling blackouts than it had been since the deadly winter storm in February 2021.