STEVE INSKEEP, HOST:
Let's get a picture of a carbon-neutral future. The U.S. is trying to change its electricity sources to produce fewer of the gases that contribute to climate change. The fight over the climate has been a partisan issue, but beyond that, it's simply a practical problem. How do you get power from cleaner sources? In earlier days on this program, we've heard about nuclear power and wind power. The next question is how to store energy from renewable sources, like wind and solar. George Crabtree is the director of the Joint Center for Energy Storage Research and an expert on batteries.
GEORGE CRABTREE: The lithium-ion battery that we have now can discharge at full power for about four hours. And that's great for intraday needs - passing clouds, gusty winds - even for extending, let's say, solar power past sunset by a few hours, and that's when there's a huge demand peak. But it cannot do, let's say, consecutive days that are overcast or that are calm. So you need a different battery for that. It won't be lithium ion. That's one of the technological breakthroughs that we're looking for, often called long-duration storage.
INSKEEP: And even aside from the duration, there's the sheer number. I'm imagining you must need, like, giant warehouses full of batteries, millions of batteries.
CRABTREE: The warehouse of batteries is exactly what is deployed next to every solar farm. And if you see them, it looks like a huge parking garage. It really takes up space. Luckily for the electricity grid, they don't have to be located in cities. They can be out where the solar farm or the wind farm is. And that's a huge advantage. So the fact that it takes up a lot of space isn't really the biggest challenge.
INSKEEP: Are there things other than batteries that can be used to store energy?
CRABTREE: There are. So things like hydrogen, which is getting a lot of play now. You could burn hydrogen in a gas turbine to produce electricity. You could use hydrogen in fuel cells that produce electricity without combustion, still a chemical reaction. Or you could simply use hydrogen to create ammonia, NH3, which is another liquid, as opposed to gaseous, chemical storage medium that people talk about.
INSKEEP: I've heard people talk about using gravity as a storage device. Would you explain how that would work?
CRABTREE: Sure. So the gravity storage, it's sometimes called, is just another form of hydroelectric storage. So you pump water uphill when you've got extra electricity. You let it flow downhill through a generator when you need the electricity. And that is actually incredibly versatile. Most of the storage we have on the grid now is pumped hydro. So although there's plenty of hydro out there now, it's not considered to be viable for the many, many storage applications on the grid that are to come.
INSKEEP: Is there some other form of gravity storage that would make sense that doesn't involve water?
CRABTREE: Sure. So you can - it works with anything that has weight. So you can lift concrete blocks with a big crane that might be half as tall as a skyscraper. And when you have extra electricity, you turn a generator, which lifts the concrete block up. When you want it back, you let the concrete block down slowly and generate electricity.
INSKEEP: I'm enjoying that because in junior high school science class, I learned about potential energy and kinetic energy. That pile of concrete blocks is potential energy sitting there, right?
CRABTREE: Exactly. And thanks for bringing it up. That's the way we talk about it.
INSKEEP: Let me ask, though, if you think that these various solutions for energy storage could be done on such a massive scale that we could do without fossil fuels for our basic electricity generation, the stuff that comes into my house.
CRABTREE: Yeah, great question. So the experts say that we could probably convert the grid 80% to renewable - that's wind and solar - without having to deal with this long-duration storage problem. We'd still use gas peaker plants for that. But that would only be for 20% of the electricity that we need. If you want to do the other 20%, you're going to have to solve that problem of storage, you know, long-term storage for the grid, days in a row. And you could do that with gravity storage. You could do that with a chemical energy carrier. It's done with methane now. So we got to get rid of the methane. But you could have hydrogen or ammonia or another chemical energy medium which is yet to be discovered. That's the challenge. We can get to 80%, but we can't get to 100%.
INSKEEP: Wow. Well, that leads to another question. People who are anxious about adaptation to climate change will ask, am I going to be forced to change my life in some way, to consume less, to use less electricity? Would people, in your imagination at least, have to change their lives in some way to get to a carbon-neutral electric grid?
CRABTREE: Yeah. And I think it's - you used the word have to change. It may be that it's not a choice. We're going to go to EVs, for example, and the vision is that we'll have 100% EVs by some date - 2035, 2050. And that will change the way that we drive. Our driving habits will not be the same. We haven't gotten serious about those cultural changes and lifestyle changes yet. We haven't had to. But I think they will come, for sure.
INSKEEP: When you see reports that say we need to make dramatic progress in terms of carbon emissions in the next 10 to 20 years, are you at all optimistic?
CRABTREE: Well, that's a good question. I think you hear a lot of pessimism in the country, and the pessimism is growing simply because the severe weather is growing. It's pretty hard to miss. But the place where the pessimism is maybe the strongest is the younger generations, the Gen Zs and the millennials, who will inherit the world, the climate change world that we older folks are leaving to them. And they're not happy about it. The young people are going to take it much more seriously, I think, than the older generations, and they're going to demand action. So in that sense, I would say there's optimism. I think you were asking, though, about - can we do it in 10 years?
INSKEEP: Yeah.
CRABTREE: We're not on track. That's clear. The United States has, through the bipartisan infrastructure bill and the Inflation Reduction Act, have put some money on the table to change that, at least in the United States. It's a bit controversial. But I would say for the first time, the government is taking it seriously. And that can be a dramatic, let's say, influence on the rest of the world. It's a global problem, for sure. It cannot be solved in any one country. All the countries have to get together to make the commitment. And maybe we're making some progress to that. Clearly, we're not there yet.
INSKEEP: George Crabtree of the Argonne National Laboratory and the Joint Center for Energy Storage Research. Thanks so much.
CRABTREE: Thank you.
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INSKEEP: We're storing up some knowledge here, and we'll continue our talks on America's energy transition tomorrow. Transcript provided by NPR, Copyright NPR.