Power grids face the summer strain

By Jeremy Beaman

Washington Examiner, Jul 14, 2022


Texas’s primary grid operator asked ratepayers to lighten their load for the first time this summer in what is expected to become an increasingly common occurrence thanks to the looming threat of blackouts.


The Electric Reliability Council of Texas issued its first “conservation appeal” of the season on July 10, a day before reserve capacity conditions were forecast to fall into shortage territory. ERCOT pointed to record high electric demand, driven by triple-digit heat indices across the drought-stricken state, as well as underwhelming wind energy output, in asking residents and businesses to turn up their thermostats and delay the use of pool pumps between 2 p.m. and 8 p.m. on July 11.


Tight supply conditions did not end up bringing any systemwide outages. ERCOT said in a statement that it “continues to monitor forecasts, and will keep Texans updated on conditions as necessary.”


The grid operator declined to identify how frequently it expects to issue such appeals this summer, but it’s unlikely to be the last one. The United States’s nationwide grid overseer said in a May report that ERCOT, which manages 90% of Texas’s electric load, is at an “elevated” risk of having insufficient electricity reserves during peak demand conditions between June and September.


The North American Electric Reliability Corporation released its summer reliability assessment on May 18, analyzing that extreme drought in the state “can produce weather conditions that are favorable to prolonged, wide-area heat events and extreme peak electricity demand.”


NERC noted that ERCOT has added new solar and wind power generation, increasing its capacity, but warned that extreme heat combined with weather patterns that are unfavorable to renewable sources may combine to stress the grid and threaten power shutoffs.


That is in part what led to the conservation appeal, ERCOT said. Wind generation was forecast to operate at 8% capacity during the peak demand period on July 11, which ERCOT said is “significantly less than what it historically generated in this time period.”


By comparison, solar generation was projected to perform at 81% capacity at the tightest demand hour, while dispatchable generation sources, such as coal and natural gas, were projected to perform at 85% capacity.


ERCOT has been under special scrutiny since grid failures and blackouts in February 2021 contributed to more than 246 deaths, but it is by no means alone in facing these stresses.


Other system operators have warned about tight capacity margins during peak demand because of transmission constraints and retirements of legacy generating sources, and NERC’s report put the entire West at elevated risk for reserve shortages.The situation is even direr this summer for parts of the Midwest and South. For Midcontinent Independent System Operator, which oversees grid operations in all or parts of Manitoba and 15 U.S. states from Minnesota down to Louisiana, NERC said the risk of shortages was high.


“More extreme temperatures, higher generation outages, or low wind conditions expose the MISO North and Central areas to higher risk of temporary operator-initiated load shedding to maintain system reliability,” NERC said.


In plain English, that means rising temperatures put customers at risk of power failures.


MISO has already been feeling the strain, having issued multiple pleas to conserve energy since the weather began heating up. Those advisories give specific instructions to generators to look for any equipment testing or maintenance that can be deferred, revoked, or canceled to keep the maximum capacity and transmission online.


California and other Western states are facing their own set of problems threatening reliability. Drought conditions are exacerbating the risk for wildfires, which can lead operators to shut off power. Less water also portends less output from hydroelectric generators, NERC warned.


Originally posted on Washington Examiner.

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