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How Our Hydropower System Is Impacting The Drought Gripping The American West

SCOTT DETROW, HOST:

A severe drought is gripping much of the American West, from Washington to Arizona. Now, we know climate change, soaring temperatures and these droughts affect our ecosystem, but what impact did they have on our nation's hydropower system? With us to discuss this is Jordan Kern, a professor at the Department of Forestry and Environmental Resources at North Carolina State University. Hey, thanks for joining us.

JORDAN KERN: Thanks, Scott.

DETROW: So let's start big picture here. What are the factors we need to think about when we think about the connection between drought, water levels and the power system in the West?

KERN: Yeah. The first direct impact the drought can have on the grid in the western United States is to reduce stream flow, which reduces the available fuel for producing hydropower. And when the Western grid loses hydropower, it has to be replaced by something. And almost always, that replacement is electricity from natural gas power plants, which are both more expensive and more polluting.

DETROW: How bad are water levels at the big hydro dams right now? How much of a drop are we already seeing?

KERN: You know, I think if you compare what the current drought to what happened in the previous really large drought that affected California, at least, from 2012 to 2016, they are probably comparable. One of the interesting things that right now on the West Coast, water levels at dams in the Pacific Northwest are not as low as they could be. And that makes a big difference because California actually imports a lot of electricity from the Pacific Northwest.

DETROW: You know, it seems like this kind of creates a cycle here - right? - where hydropower is down. That means more natural gas power is needed. And this is coming at a time when it's going to get hotter and hotter throughout the summer, and people are going to be demanding more electricity.

KERN: Yeah, that's right. The timing associated with hydropower production along the West Coast tends to coincide with the period of high snowmelt, which means April to July. And so that means that usually in the summertime, there's a reasonable amount of hydropower to help cover those increased demands for electricity that we see during the summer because people are using more electricity for air conditioning. The issue really is what happens after August, when the snowmelt is really low anyway. The real challenge will be if this drought is associated with a heat wave during those months that are dry usually. That's what really contributed to the blackouts we saw in California last year.

DETROW: You're talking about California and the northern Pacific Northwest as two different levels right now in terms of the severity of the drought and how it's affecting water supply. How much of a gap is there? How long are we looking at before Washington and Oregon are in the same bad place as California and Nevada and everywhere else?

KERN: Well, that's hard to predict, I think. You know, when you talk about the interconnection between those systems and the fact that the Pacific Northwest does deliver a lot of extra hydropower down into California and the dependency that California has on that delivered power every year, you know, I think there's a limit to the extent to which California can really rely on that. And that's a risk for them moving forward.

DETROW: You have studied the relationship between drought in California and the cost of power. Can you give us an explanation of what you have found? What specifically is there at the time?

KERN: Yeah, so drought impacts the cost of operating the grid and delivering electricity to customers in a couple of different ways. The first, of course, is a lack of water, which means you have to replace hydropower, which is essentially free to produce with something that's much more expensive, which would be replacement power from natural gas power plants. The other issue is wildfire. So the cost of wildfire does represent a pretty substantial financial vulnerability for electric power utilities. It has in recent years and is the reason that California's largest utility, PG&E, went bankrupt.

DETROW: A lot of the Western states we're talking about here have been on the leading edge of making the shift toward more and more clean energy - solar, wind, things like that. Any sense how that ongoing transition affects the system we're talking about here in terms of both cost and reliability in a situation where hydropower is dropping?

KERN: All the evidence we have suggests that, you know, a grid of the future that's presumably a lot more reliant on variable renewable energy like wind and solar will be just as susceptible to drought. For as long as the West Coast is reliant on hydropower, drought will represent a vulnerability. And the reason is because when there's a drought, you have to send more of something to California to make up for that loss of hydropower. And you can't send more wind speed or more irradiance from the sun. What you can send is more natural gas.

DETROW: What are the fixes for the cycle that we're talking about here? Because, you know, right now in Congress, we're debating an infrastructure bill. That is taking months and months. And if something is signed into law, these projects would take years and years and years to even get started and be put into place. What can grids and states do to try and be more resilient in this drought situation?

KERN: Oftentimes, the solution to reliability issues is redundancy. So you can build backup capacity, more natural gas generators, energy storage that would help get you through shorter-term events. So if you build extra natural gas power plants, it doesn't necessarily mean you have to use them all the time. You could just build them in case you have a drought. And the advantage of doing that would be that the rest of the time when you're not in a drought, you'd be using hydropower instead of that natural gas generation. But that would represent a cost to consumers. Imagine building a big power plant just to use it every once in a while during sort of rare, extreme events where you need something to turn on in an emergency. You still have to pay the mortgage on that power plant, and ultimately, that bill would fall to consumers.

DETROW: Jordan Kern, professor at the Department of Forestry and Environmental Resources at North Carolina State University, thanks for talking to us.

KERN: Thanks, Scott. Transcript provided by NPR, Copyright NPR.

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