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More demand, less supply: Drought and heat test U.S. power grid

The challenge of meeting energy demand during extreme weather is likely to be compounded as the nation seeks to rely more and more on electricity in its bid to address climate change.

WASHINGTON — The scorching temperatures and the drought pummeling the western United States are creating a perfect storm for the electric grid, exposing how future extreme weather events will increasingly push a thinly stretched power system to the brink.

As Oregon, California, New Mexico and other states grapple with record-setting heat and diminishing water supplies, Americans are relying even more on electricity and water supply systems. Yet the same factors that are driving up demand for power can also limit the ability to generate it.

From generation at power plants to the transmission lines that carry electricity to homes and businesses, just about every part of the power system performs worse in conditions that are intensely hot and dry. That raises significant questions about the nation’s readiness for a future in which, climate scientists say, global warming is expected to make extreme weather events even more common.

“This topic is on top of every utility’s agenda right now,” said Omar Al-Juburi, a digital power grid consultant at Ernst & Young. “We’re going to get to a point where the current infrastructure and the current way of operating is going to continue to be strained by these extreme heat waves.”

A dead fish from Lake Powell in the sand at Lone Rock Beach in Big Water, Utah, on June 23, 2021.Justin Sullivan / Getty Images

In Portland, Oregon, temperatures this month have hit 116 degrees Fahrenheit — an all-time high — just one year after the state saw unprecedented wildfires as early in the year as Labor Day.

“That is scary, because that means you don't know what's happened,” Bob Jenks, executive director of the Oregon Citizens’ Utility Board, said. “That means the past is no longer predictive of the future.”

A Portland-area power company even had to install extra cooling systems to prevent its own equipment from overheating. Those cooling systems themselves use electricity, as do the air conditioners that Oregonians are now buying up in droves. Jenks said that means that the next time the region faces a heat wave, there will be more air conditioners being used demanding even more power and further straining the system.

The severe drought plaguing huge swaths of the West, with lake levels dropping and riverbeds drying up, poses another challenge to keeping the power on for Americans. Fuel-burning power plants such as coal, natural gas and even nuclear plants often rely on water to cool off their systems. 

The less water nearby or available to be pumped from elsewhere, the less power those plants can safely generate, according to energy analysts. 

One of the two Nevada Intake Towers is shown at the Hoover Dam in the Lake Mead National Recreation Area, Nev., on June 15, 2021.Ethan Miller / Getty Images

A water shortage can even take a power plant offline — a scenario that has only occurred rarely and for short periods, such as at Connecticut’s Millstone Nuclear Power Station. But federal regulators are studying how to respond if that problem gets worse or more widespread.

“Researchers have shown that drought threatens coal and nuclear power plant water supplies in the Upper Midwest, and the southeastern U.S., in New England as well as the western U.S.,” Joe Smyth of the Energy and Policy Institute, a watchdog group, said.

When drought sets in, the most acute impact on electricity generation is felt by hydroelectric plants, dams that generate power from nature’s own resources, many of them federally owned and operated. Those plants provide key resilience for the electric grid through their ability to rapidly ramp up or down production to meet demand, sometimes in as little as a few seconds.

In the current drought, a lower level of water in the Colorado River is already affecting power generation and delivery, said Tracey LeBeau, who runs the U.S. Department of Energy’s Western Area Power Administration.

"Less water often results in less water running through turbines and creating electricity,” LeBeau u said. “Right now, in many regions, power is in higher demand because of the higher temperatures. So it's really a double whammy for us.”

The rocky banks of Lake Powell after waters levels dropped approximately 44 feet in the past year, in Page, Ariz., on June 24, 2021.Justin Sullivan / Getty Images

Those effects are especially pronounced at Lake Mead, on the Colorado River. The nation’s largest reservoir by volume, the lake provides the water source for the iconic Hoover Dam, which provides power for Arizona, Nevada and California.

This week, water levels in Lake Mead fell to a record low of less than 1,070 feet — 18 feet lower than it was last year. The federal Bureau of Reclamation has said the lower water levels have already reduced the dam’s electric output by a quarter, and is expected to worsen.

The blistering heat and wildfires that often accompany drought also have ramifications for other parts of the power system. 

A 2012 study from the Energy Department’s Argonne National Laboratory examining drought’s long-term impacts on power systems in the Southwest stated that during heat wave conditions, transmission lines carry power less efficiently. Gas-fired power plants don’t operate as well, and even solar panels produce less electricity under those conditions, the study said.

“Extreme weather is also impacting us with respect to wildfire danger — right now,” LeBeau said. “Throughout the last week, we've had wildfires coming perilously close to our transmission lines carrying that federal hydropower to customers.” 

High voltage transmission towers on Feb. 21, 2021 in Houston.Justin Sullivan / Getty Images file

California offers a harrowing example. In recent years, the state’s largest utility, Pacific Gas and Electric, forced outages pre-emptively because the extreme heat and power lines risked a dangerous combination, particularly during wildfire season.

“As climate change induces extreme weather events more and more frequently, we need to make investments to build a more resilient grid to carry this electricity,” President Joe Biden said Monday during a visit to La Crosse, Wisconsin.

The challenge of meeting energy demand during extreme weather is likely to be compounded as the nation seeks to rely more and more on electricity in its bid to address climate change, a transition known as “electrification.”

Smokestacks at the Jeffrey Energy Center coal-fired power plant billow smoke at sunset, near Emmet, Kan., on Sept. 12, 2020.Charlie Riedel / AP file

Rather than burning carbon dioxide-emitting gas or oil to power vehicles, stoves, and heating, ventilating and air-conditioning systems, the Biden administration is seeking to transition those devices to run on electricity. If the electricity used comes from renewable sources such as hydro, solar or wind, the process can be essentially carbon-neutral, aiding in the fight to limit climate change.

Yet, all that electricity must come from somewhere. When renewable energy sources aren’t enough, energy experts said, the backup tends to be the dirtier options: Old coal and gas power plants, or even oil-burning generators in emergency situations.

Burning those fossil fuels produces even more greenhouse gas emissions, worsening climate change by trapping heat in the atmosphere, and setting off a vicious cycle that may test the U.S. power grid more and more often at the times when Americans rely on it the most.