In 2020, California became the first state to require solar power on all new homes. The mandate is important not just for the Golden State, but because it’s seen as a prototype other states will copy. Now, activists are pursuing mandatory rooftop solar in at least ten more states. So we set off to California to find out how it’s going to so far.
Severin Borenstein: We are now seeing a lot of solar going to new houses, but the majority of solar is still going on existing houses.
Professor Severin Borenstein is from the University of California Berkeley's Haas School of Business, and studies energy policies.
Sharyl: What is your assessment of how that law has worked out so far?
Borenstein: Well, I think that it probably makes more sense to put solar on new houses, but it's still not cost-effective, compared to doing large solar farms and wind farms, where we can produce renewable energy at far lower costs.
Sharyl: As far as you know, have most new houses that have been built complied with this law —
Sharyl: And put in solar?
Borenstein: Almost all houses have. There are a few cases where you can get an exemption, but they are very narrow cases.
We first reported on California’s groundbreaking solar mandate in 2019, where some solar advocates like architect Vitus Matare were skeptical.
Sharyl: What is the problem or the challenge?
Virus Matare: Picking a panel that will have longevity and that is not a particularly wasteful process that's involved in making the panels.
Sharyl: But to be clear, you are a solar power advocate.
Matare: Yes. I just don't like the quality of the panels that we're getting and the fact that no one bothers to differentiate between crummy panels and not quite so crummy panels.
Adding to the waste issue— Matare says many of today’s solar panels don’t last very long. He showed us where he removed solar panels from his own house after less than three years.
Sharyl: You mean this spot?
Matare: This spot right here, yes. And this has happened not just here, but on a few other houses that I designed, and the owners installed panels that did not last.
Today, we get an update on implementation of California’s solar mandate for new houses more than two years in.
Sharyl: Have there been any impacts that you can tell so far?
Borenstein: Well, it does save money for homeowners, but that's because our electric prices are paying for a lot of things other than the electricity. So we have very high electricity prices in California.
Sharyl: Can you explain that? How that trade-off happens?
Borenstein: Well, what we're doing is we're subsidizing those rooftop solar by giving them a lot of credit for the amount of power they put into the grid. Much more credit than that power is actually worth, for instance, the wholesale price of electricity. And, we have to pay for that somehow. And the way we pay for it is by raising prices on all the other customers. And those other customers are the people who aren't putting in solar, who either don't own a home or can't afford to put in solar. And those people are, on average, poorer. So, those people are doing the subsidizing, and the buyers of new houses and some existing houses are getting the subsidy.
Sharyl: What are you thinking about where California is and where they're going?
Borenstein: So, what California should be doing is focusing on how can we help drive down costs, not just for California, not just for the United States, but particularly for the developing world, where most of the greenhouse gas emissions will be coming from over the next 50 years. Rooftop solar is not really a cost-effective way to do that, and it is unlikely to be a cost-effective way to do that in India and Bangladesh and China and other places. So, pursuing rooftop solar as a major part of the strategy is not a good idea. Pursuing large-scale solar — that has gotten incredibly cheap. Part of what we have to do now is figure out how to integrate a lot of that into the grid. California is way ahead of almost any other location on doing that, but there's still some challenges, particularly, at the end of the day, when the sun is setting, particularly in the summer, when there's a lot of air conditioning demand. So suddenly, you lose a lot of solar production, and you got to ramp up something else. Right now, we're doing it mostly by ramping up natural gas generation. We’re increasingly using batteries, and battery technologies have gotten a lot better and are improving every year. But we're going to have to find a combination of battery technology and other storage, trading with other locations, because the sun sets in different parts at different times, and other technologies, in order to smooth those ups and downs of renewables.
Sharyl (on-camera): California has expanded its solar panel mandate. Starting in 2023, the state will require solar panels and battery storage in new commercial buildings.