EnergyHigh Demand and Low Wind Output Spark ERCOT Conservation Appeal, System-Wide Outages Not Expected

Conservation appeals are not uncommon, especially during the summer heat and even more so now that the Electric Reliability Council of Texas (ERCOT) is operating with an abundance of caution after the 2021 blackouts. According to the operator, conservation appeals have been deployed more than four dozen times since 2008.

Such appeals are triggered when reserves are projected to fall below 2,300 megawatts (MW) for 30 minutes or more. During peak hours, one MW can power about 200 homes at once.

ERCOT cited two driving factors for this conservation appeal: record high electricity demand and low wind generation.

Temperatures in much of the state have been, and will continue to be over the next week, in the triple digits. As temperatures rise, so does the deployment of air conditioning throughout the state which means heightened use of electricity. Peak usage time comes generally from the early afternoon through the evening. On Monday, ERCOT projects the peak demand to come just before 5 p.m. and as of this morning, it projects demand to exceed available supply.

But frequently those projections are not borne out as the state works to increase capacity and reduce demand by coordinating with large industrial users to pause operations and take themselves off the grid’s load to make room for the residential pool. This is a function known as demand response and it’s a common tool employed by ERCOT to avoid dipping into its reserve margin.

To help lighten the stress on the grid, ERCOT has asked Texans to turn the thermostat up a degree or two and avoid running any major appliances during the peak hours.

That second factor — wind’s failure to produce substantially when temperatures rise and the grid’s demand peaks — is a consistent theme of Texas’ power grid. The ERCOT grid has about 35,000 MW of installed wind capacity. It tends to produce highest overnight, when the demand on the grid wanes. But it often underperforms solar generation, which has less than one-third of the installed capacity, during the hot summer afternoons. On Sunday, wind production shrunk to less than 3 percent of its installed capacity at one point.

In its conservation appeal, ERCOT stated that the forecasted peak demand on Monday will reach 79,671 MW — which it estimates grid capacity barely being able to meet.

In that forecast, the grid operator projects dispatchable power — thermal generation sources such as natural gas, coal, and nuclear along with battery storage — to produce at 85 percent of its installed capacity.

Solar is projected to produce at 81 percent of its installed capacity while wind is forecasted to produce only 8 percent of its potential.

“While solar power is generally reaching near full generation capacity, wind generation is currently generating significantly less than what it historically generated in this time period,” ERCOT stated in its release.

Back in June when the grid set a new summer demand record, which it has since exceeded multiple times, wind produced fairly well at about two-thirds of its potential. Another scare occurred in May as multiple thermal power plants unexpectedly fell offline.

But the two days prior, wind’s generation was meek. In the coming years, Texas is set to add loads more renewable electricity generation while losing coal and natural gas capacity — a phenomenon driven substantially by the available federal tax breaks for renewable sources. This influx poses hard questions for Texas’ power grid operators, especially their effect on the electricity market.

After the 2021 blackouts, the legislature commanded more caution and a concerted refocus on dispatchability — generation that can be deployed on demand, rather than being reliant on weather conditions. One of the consequences of that is higher electricity costs as ensuring more consistently available generation costs money.

The other consequence is that power plants must run longer and harder than they typically would. But despite multiple points of concern since the 2021 blackouts, the grid has held up. The state’s reserve margin has remained in normal conditions and no emergency alerts have been triggered since the February event last year.

Blackout warnings fell flat this past February and again in those May and June instances, and ERCOT has stressed it does not expect the need for rolling blackouts to reduce demand on the power grid.

Leading into the summer, ERCOT estimated the grid would reach set a new demand record, which has already been eclipsed. But the operator also estimated it’d have available 91,392 MW available to meet that demand at the times of highest stress.