Texas Power Grid Is Ready for the Summer Heat

ERCOT releases four Seasonal Assessments of Resource Adequacy (SARA) annually, in which they evaluate the grid’s preparedness for upcoming seasons. Unsurprisingly, the summer assessment holds utmost importance as the grid needs to meet the demands of numerous air conditioners running in households and commercial establishments.

ERCOT published the Summer 2023 Seasonal Assessment on May 3. Based on their analysis, ERCOT has determined that the grid possesses an adequate generation capacity to prevent the occurrence of rolling blackouts during the period of June to September 2023, assuming the presence of 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.

According to the most recent ERCOT report, there are plans to add 688 MW of fossil fuel generation and 372 MW of solar photovoltaic capacity to the grid by July 2023. Additionally, ERCOT has access to 3,544 MW of battery storage capacity, out of which it anticipates 447 MW to be available for deployment 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 2023, the ERCOT grid boasts a reserve margin of 23%, indicating a significant improvement compared to the figures of 15.7% in 2021 and 22.8% in 2022. The outlook for the next five years appears promising as new power plants scheduled for construction will further enhance the reserve margin, ensuring a more favorable balance between generation capacity and demand.

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

According to the ERCOT Seasonal Assessment for June-September 2023, which takes into account normal operating conditions and six risk scenarios, the grid is projected to have sufficient capacity to prevent rolling blackouts in the normal scenario as well as in five out of the six risk scenarios. This forecast indicates a strong readiness of the grid to meet electricity demand during the specified period, thereby ensuring a reliable power supply without the need for rolling blackouts in most scenarios.

Rolling blackouts would only be required in the most pessimistic scenario, which is characterized by a very low probability of occurrence. This scenario involves the convergence of multiple factors, including an extreme heat wave that results in exceptionally high electricity demand, simultaneous plant outages, and reduced productivity from wind turbines. While the chances of such a scenario materializing are minimal, ERCOT acknowledges the importance of considering and planning for even the most unlikely events to ensure grid reliability and resilience.

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 SCENARIOForecasted Peak LoadTypical Unplanned OutagesTypical Wind and Solar	5,034 MW	Lower than 13,576 MWERCOT grid operates normally
2) High Peak LoadTypical Unplanned OutagesTypical Wind and Solar	8,423 MW	Lower than 13,576 MWERCOT grid operates normally
3) Forecasted Peak LoadHigh Unplanned OutagesTypical Wind and Solar	8,423 MW	Lower than 13,576 MWERCOT grid operates normally
4) Forecasted Peak LoadTypical Unplanned OutagesLow 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 LoadTypical Unplanned OutagesTypical Wind and Solar	10,148 MW	Lower than 13,576 MWERCOT grid operates normally
6) Extreme Peak LoadExtreme Unplanned OutagesTypical 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 LoadExtreme Unplanned OutagesExtreme 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

If the Lone Star State experiences an extended drought or an extreme heat wave, the chances of an unfavorable scenario occurring are higher. The increased use of air conditioners during hot weather intensifies the demand for electricity, while simultaneously raising the risk of power plant failures. This unfortunate combination of circumstances arises precisely at a time when the grid requires additional power capacity.

The NERC summer assessments for 2022 and 2023 have shown significant improvements compared to the challenging conditions experienced in 2021. Following the impact of Winter Storm Uri in February 2021, which caused major blackouts across Texas, NERC expressed concerns about a similar scenario occurring during the summer months. However, subsequent assessments have demonstrated a more favorable outlook for grid reliability and resource adequacy in Texas during the summer period. These positive assessments indicate that significant efforts have been made to enhance the preparedness and resilience of the power grid in the state, mitigating the risks and potential impacts of extreme weather events.

Will Texas Have Rolling Blackouts in Summer 2023?

Both NERC (North American Electric Reliability Corporation) and ERCOT (Electric Reliability Council of Texas) have reached a consensus that Texas possesses an ample generation capacity to meet the anticipated demand during summer 2023. With a reserve margin of 23%, the grid is well-positioned to handle normal summer conditions and most of the risk scenarios evaluated. Consequently, the projections indicate that there should be no occurrence of rolling blackouts in Texas during this period.

Indeed, NERC and ERCOT’s recognition of the potential risks associated with extreme heat waves and low wind conditions is crucial. These factors have the potential to place significant strain on the power grid and elevate the probability of power outages. The analysis of data from the US Department of Energy, as examined by Climate Central, revealing a 67% increase in weather-related power outages between 2000 and 2020, further emphasizes the importance of understanding and addressing the potential impact of extreme weather events on the reliability of the power infrastructure. Such insights underscore the need for proactive measures and planning to enhance grid resilience and mitigate potential disruptions caused by severe weather conditions.

Implementing energy efficiency measures is an essential strategy for reducing the electrical load and promoting grid stability. Both homeowners and businesses can make a significant impact by adopting energy-saving practices. One effective measure is adjusting the thermostat by setting it back by 7-10°F, which not only leads to cost savings but also reduces the demand for air conditioning. When energy efficiency practices are adopted on a larger scale, the cumulative effect can alleviate the workload on the grid and help mitigate the risk of blackouts. By actively participating in energy-saving initiatives, individuals and organizations contribute to the overall stability and resilience of the power grid.