Power grids in the western U.S. are forced to handle rising temperatures

Transcript

ROB SCHMITZ, HOST:

Scorching heat broke records across the Western United States last week, and while the weekend brought some relief, excessive heat warnings are still posted for parts of states like California and Nevada. Record-setting temperatures stress people and the power grid, and they threaten power outages and health risks for those who can't escape the heat. So let's talk about how heat affects the utilities that power our lives.

Michael Webber is a professor of Mechanical Engineering at the University of Texas at Austin, who focuses on energy issues. Good morning.

MICHAEL WEBBER: Good morning.

SCHMITZ: So, Michael, how are power grids handling these dangerously high temperatures?

WEBBER: Well, it's tough on the grid, frankly, because when it's hot outside, we increase our demand for electricity significantly to run our air conditioners to keep our homes and buildings cool. So the demand goes a lot - up a lot and that really puts a strain on the grid.

But at the same time, those air conditioners and the power plants and the transmission and power lines all work less efficiently. So they actually have to work harder than normal on a hot day. And so it puts a lot of strain on the system, and it raises the risk of outages, frankly. So that's a risk that most grid planners try to plan for and design around, but as it gets hotter, it gets a little harder to do so.

SCHMITZ: Right, and I want to go into the specifics of this. Why does a power grid fail in extreme heat?

WEBBER: There are a couple things that can happen. Think of, like, you and I. If we went and ran a marathon, it'd be a lot harder to do that if it's hot outside than if it's cool outside. Our bodies just have to work harder to do the marathon and keep ourselves cool, and the same is true for the power plants. If it's hot outside, it's easier for equipment to fail at the power plant, to trip the power plant offline, and it's also easier for the power lines to fail or your air conditioner to fail. So there can be failures up and down the system.

But when it's really hot outside, you worry more about the bulk grid, about the power plants themselves failing, and it's happened historically. There have been power outages at different points over the decades during the heat waves. It's just harder for them to work when it's hot outside.

SCHMITZ: So last month, federal regulations changed the way America's electric grids are planned and funded. Are these changes going to help?

WEBBER: I think so. I think anything we can do to expand and modernize the grid is a good sign. So first of all, we need to build some more power plants. We have increasing demand as it gets hotter, but also we have increasing demand for things like electric vehicles, in the winter for heat pumps, or for data centers for artificial intelligence. So the demand for power is going up in general, and this is a good thing because that brings with it economic opportunity and helps us clean up the energy system.

So we need to build more power plants, but we also need to modernize. More sensors, more controls, more voltage support - there's a lot of things we can do, and the policies coming out of the federal government and some state governments generally are helpful in that direction, making it easier for us to expand and modernize the grid.

SCHMITZ: So more power plants - anything else that we - that needs to happen for energy systems to sort of keep up with the impact from climate change?

WEBBER: Yeah. The big low-hanging fruit in the United States is to improve our efficiency. We lag Europe, for example, in how efficient our air conditioners and our homes are. So improving, for example, the types of windows we have or the insulation at our houses will help reduce how much additional demand we need if it's hot outside, so keeping our homes cooler with less energy - that efficiency will help a lot.

We can also do things like solar panels on our rooftops and battery storage systems at our homes - that will reduce the strain on the grid and require us to install fewer power plants farther away - and then anything we can do to diversify and expand the fuel mix and not relying on the same old power plants we've always used.

Adding more wind and solar and things like that will help because the coal and natural gas and nuclear power plants that we've used for a long time - they don't work as well when it's hot outside. They - the water they use for cooling doesn't cool as well when the water is hot. So diversifying the fuel mix will help in addition to the efficiency and battery storage and that kind of thing.

SCHMITZ: So some parts of the U.S. have sort of always had to deal with summer heat waves. You know, what's different now?

WEBBER: Yeah. I'm here in Austin, Texas, and we've had heat waves since I was a kid in the '70s, so that's not new. What's different now is the heat waves start sooner. So they're starting in early May now instead of, say, July or August, and they last longer, so it's not just in September. We're now having heat waves in, like, October and early November. So the summer season is much longer. It's four or five months as opposed to three or four months. And they are at higher temperatures, these heat waves.

The other thing that's happening is it doesn't cool down at night. We had this heat dome last summer in Austin. It never got below 80 degrees for weeks on end, and so we could never turn off the power plants or air conditioners. And the whole system didn't ever cool down, and that adds additional strain when it's hot for a hundred days in a row rather than just hot for a few days.

SCHMITZ: That's Michael Webber at the University of Texas at Austin. Thanks, Michael.

WEBBER: Thank you so much for having me. Transcript provided by NPR, Copyright NPR.