Renewable energy is under fire amid rolling blackouts in California this week. Some question whether the state’s reliance on clean energy for a significant portion of its power has made it vulnerable to power losses when people need it most, such as the current heat wave. Yet clean energy is a vital component of reducing greenhouse gases to achieve climate goals.

As temperatures reached 107F today in Davis, we asked UC Davis energy economics professor James Bushnell what we need to do to get to reliable clean energy.

(Courtesy James Bushnell)

Do you think our recent blackouts are due partly to California’s reliance on solar and renewable energy?

It’s not a coincidence the blackouts are happening at sunset. There have been warnings that this is an issue, but there have been some overly optimistic assumptions about what we can do with batteries and renewables in general that make achieving 100 percent renewables, on the surface, seem less costly.

In the old days, you’d build a bunch of power plants with more capacity than we need, and if there’s an outage, you’d get the full output from the plant. When renewables came along, it added a more complicated element. Like you might have maximum output, but it’s at noon or 1 pm.

We’ve struggled with how to convert that nominal maximum into a number you can use in a planning process that you can rely on in an emergency. We need to more properly account for that and require other backup generation to handle those periods of high demand. But that raises the cost of renewables.

Do you think large-scale, reliable clean energy is achievable?

If the state is really committed to a high renewable penetration, they can make it happen, but they have to be transparent and realistic about what the costs are. I’m sure plenty of people in California would say yes, it’s worth the cost. At the same time, there are people really angry about interruptions.

I think we can improve how we cut power when there are severe events. In 2003, the eastern seaboard up to Ontario was out for up to a week during a cascading blackout. That’s the kind of Armageddon that California ISO [Independent System Operator] is trying to prevent. Instead, they instruct utilities to identify neighborhoods to rotate reductions through. This way, at least we know they’re coming, we can warn people about it, and if managed correctly, it creates like an hour of outage for people and then moves on to the next group of people.

Economists talk about real-time pricing where, in an event like this, you would see a rise in your electricity price—everything you consume between 4-8pm would cost five to 10 times more than it would. Maybe you’d decide to turn up your thermostat then or not, but people in trials do respond. The problem with blackouts is there’s no nuance—your thermostat is off. It’s not a choice between setting it to 82 or 72. Pricing can do that. Instead, we put a blunt hammer, where the entire house gets shut off.

If we want clean, reliable energy, what do you think we should do?

We don’t know all the answers. With my work, we want to design an environmental policy flexible enough to move toward the best solutions as they become apparent.

The tech du jour is batteries, which are still extremely expensive. The two obvious ways to do it is either you have a lot of batteries, which gets you through a few hours, but not two weeks of storms. The other way is to have natural gas capacity sitting around that would be used relatively infrequently. If you’re not using it much, it’s not a bad tradeoff. That’s where rigid mandates like 100-percent renewables run into problems. Trading off 90 percent renewables while natural gas meets evening needs might cost a modest fraction compared to using 100 percent renewables.

Are you suggesting we consider lowering our renewable percentage mandate?

Personally, I think it’s more important that we be more transparent of the costs of the renewable energy goals we’re trying to achieve.

Getting to 100 percent renewables isn’t impossible, but we should figure out what the right tradeoff is. We’ve gotten to the point where we’re obsessed with the electric system to the extent we might be undermining our overall climate goals.

Most plans say: “Step one: Get all carbon out of electricity. Step two: Convert everything to electric.” The problem with that is the more we put into step one, the more we increase the cost of electricity and the harder it is to attract people away from gas-powered vehicles and furnaces into electricity. There’s some kind of balance we need to do.

So you don’t think “reliable clean energy” is an oxymoron.

It’s not an oxymoron. “Reliable, super cheap clean energy” may be. But reliable clean energy we can do. It’s recognizing the cost, and also, what we should be doing now is getting more people out of regular cars and into electric cars. That’s a bigger climate benefit than squeezing more carbon out of the electric system. We can do both.

We know the importance of renewable energy. But what do you say to people reading about our blackouts and energy portfolio and thinking “Oh, crazy California?”

Something like this can give ammunition to those critics. This does show the risk of an overly optimistic climate policy. But if you go in with realistic assumptions and communicate to people about the true cost and benefits, I’m pretty sure California will still support an aggressive climate policy. But we don’t want to pretend it’s win-win-win across every portion of the economy. That can come back to bite us when one of those “wins” turns out not to be a win.