Yesterday, much of California faced level-3 energy emergency alerts as the lingering heat wave led residents to increase their electric energy usage, often in the form of air conditioning. In a level-3 alert, rolling blackouts are imminent; however, they were narrowly avoided as energy consumers reduced their usage during peak load hours, thanks to a successful texting campaign from the State Office of Emergency Services.
The risk of more intense, frequent heatwaves and other severe weather is increasing as climate change worsens. Still, the use of rolling blackouts to prevent electric energy shortages is an outdated solution. Other potential solutions include:
Reacting to energy shortfalls after they occur by relying on underfrequency relaying schemes. These are currently installed throughout the grid and shed load after frequency drops below 59.2 hertz.
Improving today’s rolling blackouts to reduce prolonged outages and exempt critical infrastructure.
Installing load sequencing panels, a burgeoning technology that selectively reduces electric load.
In this post, we’ll take a closer look at each of these potential solutions. First, let’s take a brief journey through the history of rolling blackouts. You can also learn more about how rolling blackouts work in our previous article, Rolling Blackouts are Not the Solution for Grid Deficiencies.
A 1960s Solution to a 2022 Problem
During the late 1960s and early 1970s, the demand for electricity was growing at a rapid rate each year, and there was a very real possibility that customer load could exceed generating capacity. On peak load days, customer voltage would be lowered to reduce customer load. Then, when necessary, 15-minute rolling blackouts would be initiated, manually, by switchmen. The 15-minute criteria were chosen to minimize the possibility of food spoilage.
During the twenty first century, experience has shown that rolling blackouts are an ineffective way to address energy shortfalls. After the Fukushima earthquake, rolling blackouts severely reduced industrial production until blackouts were eliminated in industrial areas. During the cold snap in Texas in 2021, rolling blackouts exacerbated the situation when power was interrupted to natural gas pressurizing facilities, water treatment plants and wastewater treatment facilities.
California’s Energy Generating Capacity Today
It's important to remember that rolling blackouts are initiated when generating capacity shortfalls are predicted, that is, before shortfalls actually occur. In California, electric energy demand is usually 38,000 MW. The state has the ability to produce 80,000 MW when all generating capacity is available, including more than 1,500 power plants utilizing a broad array of technologies. In practice, all 80,000 MW of generating capacity cannot be loaded onto the grid at the same time as grid congestion limits power flow in some areas.
Yesterday, peak demand in California reached 52,061 MW, a new record. Though this does not exceed generating capacity in the state, officials feared that customer load would exceed energy generation because of the potential for grid congestion and the concern that some generating facilities, such as solar panels, would stop producing energy during peak load hours. Instead of initiating rolling blackouts, Prescient recommends several other options to address energy shortfalls.
1. When Energy Shortfalls Occur, React
Rather than proactively initiate rolling blackouts to avoid underfrequency events, Prescient recommends that transmission system operators (TSOs) react to energy shortfalls when they occur. To do this, electric utilities should utilize underfrequency relaying schemes, which are routinely installed throughout their systems, to shed load during underfrequency events (energy shortfalls). Underfrequency relaying schemes, which are already integrated into the existing electric power grid, can eliminate proactive rolling blackouts.
Power system operators use computer models of grid infrastructure that continuously identify worst case failures and corrective actions that can be implemented. Often, the corrective action is to increase power output from higher cost generating plants, especially when solar energy production decreases after sunset. These computer models should be enhanced to include underfrequency events.
2. Improve Today’s Rolling Blackouts
Electric utilities must re-evaluate and improve the use of rolling blackouts if they choose to continue to use them as a proactive response to anticipated energy shortfalls. Utilities should ensure that outages last no longer than 15 minutes on a rotating basis, and impact only certain categories of load, such as residential areas.
Critical infrastructure, such as hospitals, water and sewage treatments plants, and police stations, should be exempt from rolling blackouts. Some industries, such as those whose recovery time is eight hours when a 15-minute outage occurs, should also be exempt.
We’ve discussed these improvements in more details in our prior article, Rolling Blackouts are Not the Solution for Grid Deficiencies. Check it out to learn more.
3. Install Load Sequencing Panels
Load sequencing panels (LSPs) should be installed in residential buildings at the circuit breaker panel to control individual circuits via an app. When an energy shortfall is predicted, LSPs can open a circuit breaker to non-essential circuits throughout a residence, such as to the clothes washer/dryer or water heater. Essential appliances, such as refrigerators or freezers, would continue to have power.
Load sequencing panels can also be installed in businesses with similar applications. They can shut off power to circuits that control air conditioning, lights, or other non-essential loads, or shut off all power after business hours.
By using LSPs to disable specific circuits, electric energy consumption can be curtailed without the need for rolling blackouts. Learn more about load sequencing panels in our other articles, including:
Rolling Blackouts are Unnecessary in the 4Ge Grid
As we move towards the 4th generation (4Ge) electric power grid, rolling blackouts will be recognized as an outdated and unnecessary response to anticipated energy shortfalls. For many Californians, last night’s looming threat of rolling blackouts may have resulted in decreased confidence in the reliability of the electric power grid, and, by extension, electric utilities. Instead, electric utilities should implement any of the three solutions outlined above.
This article was written in collaboration with Prescient's Lead Editor Alyssa Sleva-Horine.