Too Much Solar? How California Found Itself Facing an Unexpected Energy Challenge

SACRAMENTO, Calif. — It’s a common sight across the state: rows of suburban homes with solar panels atop them.

But as California works toward its ambitious clean-energy vision, an almost counterintuitive challenge has emerged: The state is sometimes generating more solar power than it can handle. It’s gotten to the point where a lot of clean energy is being wasted.

The phenomenon, which other states are likely to encounter as they ramp up their own solar production, has been dubbed the “duck curve.” The duck’s belly is the time of day when solar production can exceed demand. Because solar energy relies on the sun, the curve is often most visible on sunny days in the spring, when fewer people use electricity and turn on their air conditioning.

“There are times of the year, especially in the spring, when demand for electricity is not as high, and there is enough solar generation that in some circumstances we have more than California can actually use,” said Elliot Mainzer, CEO of California’s Independent System Operator, which manages 80% of the state’s electricity flow.

“In that environment, we’re taking advantage of a significant amount of transmission connectivity that we have with other parts of the West, and we’re exporting a lot of that power to other utilities in the Western United States,” he said.

“In certain extreme conditions we have to limit and completely disable this function,” he added.

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The amount of renewable energy that has been curtailed or wasted has skyrocketed in recent years, according to the Independent System Operator, both because of oversupply and because of so-called congestion, when there’s more electricity than transmission lines in some areas can handle. This year, the state has lost nearly 2.6 million megawatt-hours of renewable energy — most of it from the sun — more than enough to power all the homes in San Francisco for a year.

Mainzer said adding transmission lines would help increase the flow of electricity across the state and he favors authorizing reform to accomplish that goal.

“When you build a new solar project or a new battery or a new wind project or a new geothermal resource, if you don’t have the transmission lines available to access it and get it to customers, that generation is essentially an island. It’s trapped,” he said.

Gov. Gavin Newsom’s administration has also pushed to add more batteries to store excess energy for use during peak demand. And state regulators at the California Public Utilities Commission have taken a more controversial approach: drastically cutting financial incentives for homeowners who want to install solar panels.

The move has outraged many in the rooftop solar industry, including Ed Murray, president of the California Solar and Storage Association, which runs Aztec Solar outside Sacramento. The changes, he said, have been devastating for his company. He said he has laid off 10 workers in the past year.

“Sales were down because nobody wanted it anymore,” Murray said. “It wasn’t productive or profitable to be in solar, so we had to figure out what to do next.”

According to the California Solar and Storage Association, residential solar installations fell 66% in the first quarter of 2024 compared with the same period in 2022. The industry group estimates that 17,000 green jobs have been lost statewide since the state changed its incentive structure, known as net metering.

To make the new state incentives worthwhile, homeowners must now install batteries in addition to solar panels, but that can cost an additional $10,000 to $20,000 or more.

“It’s an easy fix, but it’s expensive,” Murray said. “Because people don’t want or can’t afford batteries, unfortunately.”

Newsom defended the state’s policy in his statement, saying there have been nearly 100 days this year where clean energy met 100% of demand during some part of the day.

“No other state in America comes close to California’s solar production,” he said. “We’re generating nearly 20 times more solar energy than we did a decade ago, powering millions of homes with clean energy. And now we’re adding more batteries faster than ever to help capture that energy for use at night.”

Supporters of the state’s incentive changes also point to equity concerns, arguing that switching to solar could raise the cost of energy for those who don’t have it or can’t afford it.

In announcing the decision in 2022, John Reynolds, a member of the Public Utilities Commission, said net metering “has done an incredible job and has brought solar power to hundreds of thousands of Californians, but it is also incredibly costly to non-solar customers and needed to be reformed.”

Murray disagrees with that argument, saying most of his clients make between $50,000 and $60,000 a year, often taking out loans at a time when interest rates have risen sharply.

Murray believes that given California’s position as a leader in solar energy, other states are watching the situation and may follow suit.

“I’m hearing from Florida, Arizona, Minnesota, Massachusetts, that they’re thinking about copying the rules, that they’re going to change the rules of the game,” he said. “They’re nervous because it’s going to hurt across the board.”

“As we grow, California grows, and typically the rest of the country grows with it,” he added.

It’s an example of how, as California embarks on a historic transition to clean energy — with a goal of achieving 100 percent clean energy by 2045 — new challenges are casting doubt on the path to a renewables-based future.

“There’s no way we’re going to get there without solar panels on roofs,” Murray said. “Electric vehicles, heat pumps, electric cookers — that’s not going to happen without solar panels. Period.”

This article was originally published on NBCNews.com