Last Updated on May 18, 2023 by Mary Pressler
The Texas Power Grid Is Ready for the Summer Heat
ERCOT publishes four Seasonal Assessments of Resource Adequacy (SARA) each year, where they analyze if the grid is ready for the next season. As you might expect, summer is the most critical season since the grid must be able to power thousands of air conditioners in homes and businesses.
ERCOT published the Summer 2023 Seasonal Assessment on May 3. They concluded that the grid has enough generation capacity to avoid rolling blackouts in June-September 2023, under typical summer weather conditions.
- The report forecasts a record-breaking peak demand of 82,739 MW.
- Adding large flexible loads such as crypto mining facilities (1,105 MW), and subtracting distributed generation (432 MW), the adjusted peak demand forecast is 83,412 MW.
- However, the ERCOT grid has access to 96,988 MW of capacity under normal conditions, and an additional 4,577 MW of emergency resources.
The latest ERCOT report includes 688 MW of fossil fuel generation and 372 MW of solar photovoltaic capacity that are scheduled for July 2023. ERCOT also has access to 3,544 MW of battery storage capacity, and 447 MW are expected to be available for dispatch during peak-load hours.
The ERCOT grid has a reserve margin of 23% in 2023, which represents an improvement from 2021 (15.7%) and 2022 (22.8%). There is a favorable forecast for the next five years, since new power plants scheduled for construction will continue to improve the reserve margin:
| Year | Demand Forecast | Capacity Forecast | Planning Reserve Margin |
| 2024 | 81,643 MW | 109,207 MW | 33.8% (27,564 MW) |
| 2025 | 83,058 MW | 119,593 MW | 44.0% (36,535 MW) |
| 2026 | 84,449 MW | 121,570 MW | 44.0% (37,121 MW) |
| 2027 | 85,836 MW | 121,873 MW | 42.0% (36,037 MW) |
| 2028 | 86,408 MW | 121,873 MW | 41.0% (35,465 MW) |
NOTE: The figures in this table will change with updated forecasts from ERCOT.
In July 2022, power demand in the ERCOT region surpassed 80,000 MW for the first time ever. The 83,412 MW forecast for summer 2023 would represent a new record.
According to the National Oceanic and Atmospheric Administration (NOAA), 2023 had the second-warmest March and fourth-warmest April on record. There is a 93% probability that this year will be among the top five warmest so far. Power grid operators must be ready for a high air conditioning load when the hottest months arrive.
Does ERCOT Have a Rolling Blackout Schedule?
Power grids use rolling blackouts as an emergency measure when they can no longer meet electricity demand. Since these emergencies are unpredictable, ERCOT does not have a rolling blackout schedule.
ERCOT uses the Energy Emergency Alert (EEA) system to report the current state of the grid. Under emergency conditions, the EEA system is also used to decide if rolling blackouts are necessary. The system uses four alert levels of increasing severity:
| ERCOT Grid Status | Alert Color | Description |
| Normal Conditions | Green | The grid is operating normally with a reserve margin of more than 3,000 MW. |
| Conservation Alert | Yellow | The operating margin has dropped below 3,000 and ERCOT asks consumers to conserve energy. |
| Energy Emergency Alert Level 1 (EEA1) | Orange | The operating margin has dropped below 2,300 MW. ERCOT will use all power supplies available, such as interconnections with neighboring grids. |
| Energy Emergency Alert Level 2 (EEA2) | Red | The operating margin has dropped below 1,750 MW. ERCOT will disconnect large consumers who have agreed to be switched off during emergencies, but rolling blackouts are not applied yet. |
| Energy Emergency Alert Level 3 (EEA3) | Black | The operating margin has dropped below 1,000 MW and ERCOT uses rolling blackouts. Transmission companies are given instructions to disconnect loads at their discretion. |
There is a higher risk of energy emergency alerts between 6pm and 8pm, and the maximum risk is at 7pm.
- When the Summer 2023 Seasonal Assessment was published on May 3, ERCOT had not reported the probability of EEA1 events.
- However, the North American Electric Reliability Corporation (NERC) also conducts power grid assessments, and they estimated that ERCOT has a 4% risk of EEA1 in summer 2023.
This represents an improvement from 2021 and 2022, when the risk of energy emergency events was 12% and 6% respectively.
Rolling blackouts are also called rotating outages, and they are controlled electric service interruptions that normally last 10-45 minutes. These power outages are called “rolling” or “rotating” because different parts of the grid are disconnected by turns to reduce consumption.
ERCOT Electric Grid Assessment: Summer 2023 Risk Scenarios
The ERCOT Seasonal Assessment for June-September 2023 considers normal operating conditions and six risk scenarios. According to their forecast, the grid has enough capacity to avoid rolling blackouts in the normal scenario and five of the six risk scenarios.
Rolling blackouts would only be needed in the most pessimistic scenario, which has a very low chance of happening: getting an extreme heat wave that produces high demand for electricity, combined with multiple plant outages and low productivity from wind turbines.
The table below summarizes the seven scenarios considered in the Summer 2023 SARA Report, and the reserve capacity needed in each case.
- The reserve capacity available under normal conditions is 13,576 MW.
- ERCOT can deploy an additional 4,577 MW for emergency conditions.
- Adding normal and emergency reserves, ERCOT can access 18,153 MW.
| Risk Scenario Grid Conditions | Reserve Capacity Required | ERCOT Risk Assessment |
| 1) BASE SCENARIO
Forecasted Peak Load Typical Unplanned Outages Typical Wind and Solar |
5,034 MW | Lower than 13,576 MW
ERCOT grid operates normally |
| 2) High Peak Load
Typical Unplanned Outages Typical Wind and Solar |
8,423 MW | Lower than 13,576 MW
ERCOT grid operates normally |
| 3) Forecasted Peak Load
High Unplanned Outages Typical Wind and Solar |
8,423 MW | Lower than 13,576 MW
ERCOT grid operates normally |
| 4) Forecasted Peak Load
Typical Unplanned Outages Low Wind and Solar |
15,940 MW | Exceeds 13,576 MW (normal reserve)
Lower than 18,153 MW (emergency reserve) Risk of EEA Level 1 but no blackouts yet |
| 5) Extreme Peak Load
Typical Unplanned Outages Typical Wind and Solar |
10,148 MW | Lower than 13,576 MW
ERCOT grid operates normally |
| 6) Extreme Peak Load
Extreme Unplanned Outages Typical Wind and Solar |
16,321 MW | Exceeds 13,576 MW (normal reserve)
Lower than 18,153 MW (emergency reserve) Risk of EEA Level 1 but no blackouts yet |
| 7) High Peak Load
Extreme Unplanned Outages Extreme Low Wind |
24,962 MW | Exceeds 18,153 MW (emergency reserve)
Risk of EEA Level 3 and rolling blackouts |
There is only one scenario where Texas would suffer rolling blackouts (EEA3), and it only happens with a combination of extreme conditions:
- High peak load
- Extreme unplanned outages
- Extreme low wind
This scenario has a very low risk of happening, since it would require an extreme heat wave combined with low winds.
There are two scenarios where ERCOT reaches Energy Emergency Level 1, but blackouts can be prevented by using the emergency capacity of 4,577 MW.
NERC Reliability Assessment for Summer 2023: ERCOT Region
NERC also publishes seasonal power grid assessments, which cover the US and Canada. NERC assessments of the Texas power grid are normally less optimistic than those published by ERCOT. However, NERC agrees that ERCOT has improved its reliability in 2023.
NERC also reported a reserve margin of 23% for the ERCOT region, which is much higher than their minimum recommendation of 13.75%. Their report also identifies two major improvements that are helping the Texas grid:
- Adding over 4,000 MW of solar photovoltaic capacity since summer 2022.
- 3,380 MW of cumulative load reduction with demand response programs.
In spite of their positive assessment, NERC identifies risk factors that can bring the grid to its limit if they are combined:
- Extreme peak demand during heat waves
- Low winds
- High outage rates at thermal power plants
An unfavorable scenario is more likely if the Lone Star State suffers an extended drought or an extreme heat wave. Hot weather increases the electricity usage of air conditioners, but also the risk of power plant failures – exactly when the grid needs more power!
NERC summer assessments in 2022 and 2023 have been much more favorable compared with 2021. Texas had been hit by Winter Storm Uri in February 2021, and there were major blackouts throughout the state. Back then, NERC was concerned about a similar scenario in summer.
Conclusion: Will Texas Have Rolling Blackouts in Summer 2023?
NERC and ERCOT agree that Texas has enough generation capacity to cover demand in summer 2023, with a reserve margin of 23%. Under normal summer conditions and in most of the risk scenarios considered, there should be no rolling blackouts in Texas.
However, NERC and ERCOT also agree that extreme heat waves are a risk factor that should not be ignored, especially if combined with low winds. Using data from the US Department of Energy, Climate Central determined that weather-related power outages increased by 67% between 2000 and 2020.
Homeowners and businesses can use energy efficiency measures to reduce their electrical load. At large scale, energy efficiency can reduce the grid workload and lower the risk of blackouts. Setting back your thermostat by 7-10°F is a simple and effective measure: you can save up to 10% in air conditioning costs!