Texas regulators questioned CenterPoint Energy executives on Aug. 15 about how they used - or did not use -- about 511 MW of leased mobile generation capacity after Hurricane Beryl cut power for about 2.2 million Houston-area customers upon its July 8 landfall, of which about 10% remained offline a week later.

One of the more contentious issues that arose in the storm's wake was CenterPoint's use of about $800 million from Temporary Emergency Electric Energy Facilities utility rider to lease temporary generators to be used in emergencies. The Texas Legislature allowed this action in 2021 in the wake of a deadly mid-February 2021 winter storm, known as Winter Storm Uri, that cut power to about 4 million Texas customers, some for days.

Jason Ryan, CenterPoint senior vice president and general counsel, said CenterPoint leased small, medium and large generators with these funds. An Aug. 12 filing provides some details:

In all, the least costs total almost $766 million, and mobilization costs add another $25.4 million.

"One of the risks obviously that we mitigate with primarily the large units is load shed," Ryan said. "Again, this legislation came in the aftermath of a Winter Storm Uri where we at Houston had to turn off 5,000 megawatts of customer usage during that event."

Houston is unique in Texas, as it occupies about 3% of Texas but consumes about 25% of the Electric Reliability Council of Texas power, Ryan said.

"We have the largest petrochemical complex on the planet, and we do not rotate outages to those large industrial customers for public safety and other reasons," Ryan continued. "So, when we have to shed 5,000 megawatts of load, that burden falls completely on residential and small commercial customers."

But the large generators require more time and cranes to assemble and begin operating, said Eric Easton, CenterPoint vice president for grid investment strategy.

The smaller units were operated "for about 3,000 hours total during Hurricane Beryl, so they definitely made a difference in the lives of the people that were served by these assets during the event," Ryan said.

"So, what this means in reality is when these extreme events happen, you are not likely to ever use every asset in our fleet of temporary emergency generation during each one, just like you don't use every tool in your toolbox at home to do a project, but you need all of the tools because you might do a different project the next weekend," Ryan said.

But Commissioner Lori Cobos questioned the lack of deployment of the whole fleet in the aftermath of Hurricane Beryl, and Commissioner Jimmy Glotfelty also questioned how the leases were structured.

In testimony before the Texas Legislature passed legislation allowing transmission and distribution utilities to lease temporary generators, Cobos said: "You guys really sold this mobile generation and submitted a lot of testimony here in your distribution cost recovery factor docket talking about how these mobile generation units can be used for hurricanes, and the fact of the matter is, the majority cannot be used for hurricanes."

"Now, we are in a place after Hurricane Bery, where there has been devastating impacts in the service territory," Cobos said. "People died. ... There's a lot of kind of talking out of both sides of your mouth on this issue, doing little dances and pointing at different facts to justify your decision, but the fact of the matter is that we are here, and we want to figure out what we're going to do with this fleet."