ERCOT sees adequate resources to meet record-setting summer electricity demand


The Electric Reliability Council of Texas (ERCOT) said it expects record-breaking electric demand this summer due to hot and dry conditions and continued economic and population growth.

As part of its forecasting effort, ERCOT identified in its summer assessment low-probability, high-impact situations similar to the February winter event. The grid, which serves about 90% of the state’s electricity load, nearly collapsed when a winter storm knocked thousands of megawatts of generating capacity off line for days.

The grid operator also announced plans to visit selected power plants to review summer weatherization plans. It said that plant visits have occurred in the past for winter weatherization, but this is the first time officials will visit plants for summer.

Rooftop solar offsets

ERCOT said it anticipates a summer 2021 peak demand of 77,144 MW. The total includes load reductions based on rooftop solar capacity forecast. Even with the help of rooftop solar, this would be a new system-wide peak demand record for the region, ERCOT said. The outlook includes a high peak demand forecast of 80,178 MW based on 2011 summer weather conditions.

Solar is on track to make up the largest share of new capacity additions in Texas between 2020 and 2022. Almost 50% of the additions during this time period will be solar, surpassing wind (35%) and natural gas (13%) additions, according to the Energy Department’s Energy Information Administration (EIA).

In April, EIA said that California currently has the most installed utility-scale solar capacity of any state. But Texas is expected to add 10 GW of utility-scale solar capacity by the end of 2022, compared with 3.2 GW in California. One-third of the utility-scale solar capacity planned to come online in the United States in the next two years (30 GW) will be in the Lone Star State.

ERCOT said it anticipates 86,862 MW of resource capacity to be available during summer peak demand hours.

Image: ERCOT

In the mix

ERCOT said it anticipates 86,862 MW of resource capacity to be available during summer peak demand hours. The mix which includes 4,808 MW of planned utility-scale solar, gas-fired, and wind capacity. ERCOT also said it expects to have 853 MW of operational battery storage resources, including 618 MW of planned additions.

ERCOT counted 4,325.5 MW of operational solar capacity that it expects to be available this summer. It gave those resources a peak average capacity factor of 80%. It also counted 234.6 MW of currently available storage capacity.

It also counted more than 25,000 MW of wind capacity. It pegged average capacity percentages at 61% for wind turbines sited in coastal counties, 29% for capacity in West Texas Panhandle counties, and 19% for other locations.

Tallying the toll

More evidence of the severity of the February winter storm came from the Energy Department’s Energy Information Administration (EIA), which said that U.S. natural gas production averaged 104.8 billion cubic feet per day (Bcf/d), an 8.1 Bcf/d (7%) drop from January, and the largest monthly decline on record.

ERCOT counted 4,325.5 MW of operational solar capacity that it expects to be available this summer, and gave those resources a peak average capacity factor of 80%.

Image: NREL/Dennis Schroeder

A drop natural gas production in Texas accounted for most of the overall decline, EIA said. Texas natural gas production fell by a record 4.3 Bcf/d (15%) to 21.5 Bcf/d during February.

Meanwhile, NRG Energy reported a first quarter loss of $967 million due to effects of the storm. The company said that over time that loss could be trimmed to between $500 to $700 million. It said offsets could include customer bad debt mitigation, counter-party default recovery, ERCOT default and uplift regulatory securitization, and one-time cost savings.

Outage forecast

The ERCOT summer outlook included a thermal and hydro outage forecast of 3,642 MW based on historical outage data from the past three summer seasons (starting with 2018). The high outage forecast assumes a 2,601 MW increase in forced outages, resulting in total outages of 6,243 MW.

Including load reduction resources that can be deployed during Energy Emergency events, the 2021 summer planning reserve margin is 15.7%.

Risk factors

ERCOT said that tight grid conditions have historically been limited to the hours of highest electric consumption. The grid operator said that it now sees the potential for tight conditions during low wind conditions, or during the early evening hours when solar resources come offline. It said that as the capacity of battery storage increases, these resources are expected to help mitigate some of the risk.

ERCOT said it is also monitoring current drought conditions across the state. After consulting with generators on their risk mitigation plans, the grid operator said it “does not believe the drought poses a significant risk at this time.”

Between mid-May and the end of June ERCOT officials will visit power plants to assess their readiness for the summer demand season. ERCOT said it will generally give priority to those sites that had one or more thermal generation resources experience some form of outage during summer conditions within the past few years. It said is will also randomly select a number of other thermal generation sites for inspection.

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