Strained by the Heat, But Not Powerless


Strained by the Heat, But Not Powerless
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It used to be news when the electric power failed.

But in today’s topsy-turvy world of energy, Southwest Power Pool of Little Rock put out a news release July 8 trumpeting the fact that it kept the lights on.

With extreme summer heat oppressing the central United States over the Independence Day holiday week, the regional electricity transmission organization “partnered with its member utilities to keep the power on for millions of people over several days of record-setting electricity use and high temperatures.”

Bravo, you might respond ironically, but the fact is keeping the juice flowing when demand is greatest has always required coordinating excess capacity in generation and transmission, and threading the needle of data and reaction has become harder as we settle into the era of climate change and its frequent extreme weather.

July 5 was as hot as the Fourth of July, and at 4:30 that afternoon SPP’s 17-state grid operation hit a new all-time peak load of 51,090 megawatts, topping the 51,036 MW load set last July 28. 

Renewable energy was part of the rescue, officials said.

“At the time of the new record, SPP relied on a mix of energy sources including traditional fossil fuels, renewables, nuclear power and other types of generation,” the not-for-profit grid operator said. Electricity-use timing known as demand response added 1.1 megawatts to the fuel mix, SPP said.

Demand response programs sign up customers willing to cut their power use at their utility’s request, during peak demand spikes or other times when there’s not enough power to go around. These customers get money back for doing things like turning off lights and air conditioning, or waiting till after dark to wash or dry clothes.

The power savings in each example are small, but when thousands of power users participate, their adjustability can be just enough to save the grid in a pinch.

SPP anticipated the hellish spell, declaring a conservative operations advisory on July 1, effective at noon July 6 and running through 10 p.m. July 8. The alert advised member utilities to operate the regional grid with extra care, suggesting things like postponing maintenance on critical facilities, increasing reserve requirements and more. The grid operator and its members maintained reliability through two of the hottest days of the year on July 6 and 7; the regional load peaked those days at 49,972 megawatts and 50,230 megawatts, respectively.

SPP Senior Vice President of Operations Bruce Rew noted how essential electricity is when air conditioning is literally a lifesaver. “At the same time,” he said, “preventing service interruptions has become a more and more complex challenge.”

Periods like the week of the Fourth “underscore how much value there is in regional collaboration,” Rew added. “We’re proud of the job we do coordinating among our member utilities to keep the lights on through careful reliability coordination, thoughtful and thorough system planning, and administration of a stakeholder process that ensures mutually beneficial decisions are made.”

SPP is licensed by the Federal Energy Regulatory Commission to keep the regional supply of electricity in balance across 14 states of the U.S. heartland from the Canadian border in North Dakota to the Texas Panhandle. It monitors and forecasts minute-by-minute electricity use and dispatches power from more than 900 utility-owned generating units to meet demand, the company said in a news release.

Meanwhile, the heat is back on SPP’s grid-operating neighbor to the west, the inaptly named Energy Reliability Council of Texas.

ERCOT played the villain with its unreliability in the February 2021 deep freeze and snowstorm that crippled Texas’ grid and contributed to the deaths of more than 200 people. Some froze to death in their homes; others died of carbon fumes in cars, or from lack of power to their medical devices.

So last week, while SPP was on its mini-victory lap, ERCOT was warning Texans to either conserve power or face the prospect of sweating in the dark. It issued a “conservation watch” on July 11 as extreme heat drove record power demand across the state. “Turn down your thermostat to 78 degrees,” the reminder said, and apparently it worked.

Energy demand plunged between 1:56 and 2 p.m. as the conservation appeal drove action. Demand fell by about 500 megawatts, enough electricity to power 10,000 homes, enough to take the edge off a peak of 78,264 megawatts, another daily record.

The ERCOT grid got back to normal conditions Monday, July 11, but more extreme heat is in the late-July forecast.