Energy Central Professional

 

So far so good for power grid, but more tests lurk


Bob Sechler  

 

    In a news conference last month, utility commission Chairman Peter Lake said he has "absolute confidence" that "the lights will stay on this summer," meaning there won't be any systemic grid failures causing power outages. The comments by Lake, who was appointed to his post by Gov. Greg Abbott in April 2021, echoed assertions both he and Abbott made in advance of the winter.

    If you view the recent bout of triple-digit temperatures and record statewide electricity demand as a test for the Texas power grid, it's been more akin to a pop quiz than a full-fledged exam.

    That's because greater challenges are on the way, experts say.

    "It's not even officially summer yet" until June 21, said Beth Garza, a former Austin Energy manager and independent market monitor for the Electric Reliability Council of Texas, which operates the power grid.

    "The forecasts that I have seen are for it to be very hot and very dry (throughout the summer), and that is going to put more stress on the grid" because of high consumer demand and continuous strain on power generators, Garza said. "That means the bigger risks are ahead of us."

    Still, the good news for ERCOT — and for the 90% of Texas electricity customers who get their power from the grid it manages — is that the June heat wave doesn't appear to have caused major difficulty so far.

    Renewed questions about the grid's ability to handle unusual stress arose little more than a month ago, when ERCOT issued a call for consumers to turn the thermostats on their air conditioners up to 78 degrees or warmer and otherwise conserve electricity heading into an unseasonably hot weekend in mid-May.

    Coming in the wake of the February 2021 grid disaster — when prolonged blackouts during a severe winter freeze contributed to hundreds of deaths and billions of dollars in property damage — the springtime request for conservation sparked jitters about the power system's reliability with the hottest months of the year around the corner.

    Over the past couple of weeks, however, the grid has been delivering huge amounts of electricity without obvious hitches, aside from ERCOT's request at one point this month that power generators defer maintenance and stay online. Electricity usage has notched a series of all-time highs, resulting from the extremely hot temperatures for June and the impact of booming statewide population growth.

    Peak demand on the ERCOT grid hit 75,124 megawatts Thursday, surpassing a record 74,917-megawatt peak set just days earlier on June 12, and new records could be set over the coming week. One megawatt of electricity is enough to power about 200 homes on a hot day.

    Prior to the current record-breaking stretch, the previous all-time high for peak demand was 74,820 megawatts on Aug. 12, 2019.

    Grid likely to need 'every resource available'

    The grid's success in coping with the big demand so far in June has been aided by strong generation from wind farms and solar arrays — and by the fact that there have been no major problems reported by generators that have affected the overall system.

    ERCOT's request in May for conservation came after six natural gas-fueled power plants unexpectedly tripped offline amid the hot weather. Officials who oversee the grid have characterized the subsequent call for conservation as merely precautionary and said system conditions never reached emergency status.

    But it remains to be seen if that will hold true throughout the summer.

    "If we are already hitting records (for peak electricity demand) now, we know we are going to hit even more records in the next few months" when temperatures climb even higher, said Dave Tuttle, an Energy Institute research associate and lecturer at the University of Texas. "Will that track record of being able to handle new records continue?"

    Tuttle considers the most likely answer to be yes — but he said it's not a certainty. "We are probably going to need every resource available come August," he said.

    With the high temperatures driving the demand for electricity, National Weather Service meteorologist Nick Hampshire said it's too early to tell if the weather over the next few months will be even worse than the sweltering heat wave that plagued Texas during the summer of 2011, which shattered previous benchmarks and is the hottest on record.

    But there are already similarities to that scorcher, and Hampshire said it's "highly likely we will be above normal" for the rest of this summer.

    For instance, there have been 10 days through June 14 in which temperatures at Camp Mabry in West Austin have hit 100 degrees or higher, identical to the number recorded during the same stretch of 2011, he said.

    Austin also had its first 100-degree day on May 21 this year — about six weeks before the average date of July 4 for the area's first 100-degree day.

    Still, top officials of ERCOT and the Texas Public Utility Commission, which oversees ERCOT, have consistently said they expect sufficient generation capacity to be available to serve demand this summer.

    ERCOT officials express confidence

    ERCOT has forecast peak demand at 77,317 megawatts — which is even higher than the recent record-breaking figures — and said 91,392 megawatts of generation capacity should be available to handle it, providing the system with an ample reserve cushion under most scenarios it has modeled.

    In a news conference last month, utility commission Chairman Peter Lake said he has "absolute confidence" that "the lights will stay on this summer," meaning there won't be any systemic grid failures causing power outages. The comments by Lake, who was appointed to his post by Gov. Greg Abbott in April 2021, echoed assertions both he and Abbott made in advance of the winter.

    Lake has said his conviction is based on reforms made to the grid since the February 2021 disaster and on ERCOT's ongoing effort to manage the system more conservatively.

    Among those moves, ERCOT has been purchasing additional backup power reserves, with the tab totaling about $380 million from June 2021 through early May this year. Ratepayers are picking up the cost, but Lake said the sum equates to just $1 a month per household in the ERCOT system.

    "So, Texans, for $1 per month, are receiving a vastly more reliable grid to ensure that the lights stay on," he said.

    Numerous outside experts have questioned such certitude regarding the grid's reliability, however, noting that ERCOT has consistently underestimated monthly peak demand and that some of the agency's own models for this summer indicate generation capacity could fall short if certain extreme circumstances occur that it considers improbable.

    More stress coming for grid

    Utility commission and ERCOT officials "are in no position to make a guarantee about the performance of generators," said Ed Hirs, a University of Houston energy economics professor.

    "We saw that on Friday the 13th," he said, referring to the Friday in May when ERCOT issued its call for consumers to cut back on electricity usage after the six power plants unexpectedly tripped offline.

    Hirs said he thinks Texans "should be concerned about the grid holding up through the summer," noting that ERCOT's requests for generators to defer maintenance and stay online at certain points this month and in May "catches up with equipment that is stressed."

    The grid "hasn't been stressed as much as it's going to be in August," when temperatures probably will be even hotter, he said. "We will not know if (the grid) holds up until the system is tested" by the weather to come.

    Garza, a senior fellow at think tank R Street Institute, said sustained hot temperatures have a cumulative negative impact on generation infrastructure, such as by heating up the surface water that some power plants use for cooling. She also said the late summer typically isn't as windy as June, meaning there might be less output available from wind turbines over the coming months.

    Still, she pegged the chance of a systemic grid failure that triggers rotating blackouts at less than 50%. She stopped short of guaranteeing it won't happen, however.

    "That is certainly not a pledge I would be comfortable making," Garza said. "The risks of having a major system issue will only increase the longer we have these extremely hot temperatures."

    In a news conference last month, utility commission Chairman Peter Lake said he has "absolute confidence" that "the lights will stay on this summer," meaning there won't be any systemic grid failures causing power outages. The comments by Lake, who was appointed to his post by Gov. Greg Abbott in April 2021, echoed assertions both he and Abbott made in advance of the winter.

TOP


Copyright © 1996-2022 by CyberTech, Inc. All rights reserved.
Energy Central® and Energy Central Professional® are registered trademarks of CyberTech, Incorporated. Data and information is provided for informational purposes only, and is not intended for trading purposes. CyberTech does not warrant that the information or services of Energy Central will meet any specific requirements; nor will it be error free or uninterrupted; nor shall CyberTech be liable for any indirect, incidental or consequential damages (including lost data, information or profits) sustained or incurred in connection with the use of, operation of, or inability to use Energy Central. Other terms of use may apply. Membership information is confidential and subject to our privacy agreement.