While a regulatory battle over energy policy rages in Washington, D.C., the solar industry is raising alarms that the outcome has the potential to cripple rooftop solar in California and around the country.

A secretive, New Hampshire-based nonprofit called the New England Ratepayers Association petitioned the Federal Energy Regulatory Commission in April to reevaluate the core tenets of net metering, a billing method that’s foundational to rooftop solar. While NERA argues the policy that many states have adopted unfairly benefits people who can afford solar panels, the solar industry claims NERA is simply hell-bent on wiping out competition to utilities.

“It feels very simple to me. This is just a complete, existential attack on solar,” said Dave Rosenfeld, executive director of the Solar Rights Alliance, which advocates for solar users in California. “And in just one fell swoop, it would devastate solar.”

For years, FERC has maintained that states have jurisdiction over net metering and that it would not take control. In its petition, NERA is asking the federal agency to do just that.

FERC is accepting public comments until June 15.

How net metering works

Here’s how net metering works. If you have solar panels installed on your house, you likely use less electricity during the day than the panels generate. Those excess electrons are pushed onto the grid, and you receive a credit that counts against your bill for the power you’ll need to purchase from the local utility at other times, like at night, during cloudy days or during hours of peak demand.

The policy is a big reason why California celebrated hitting 1 million homes with solar panels last year.

But if the predetermined value of that electricity pushed onto the grid changes by a few cents per kilowatt hour, it could mean the difference between a homeowner being able to afford rooftop solar and avoiding it altogether. One of NERA’s asks is that the rate be changed, potentially making the credits that solar users earn three- to five-times smaller, by its own estimate.

“For people who have solar, it pulls the rug out from under them and ruins their investment,” Rosenfeld said.

What the move could mean

Solar advocates argue that if FERC approves the petition, trends in new rooftop solar installations would would mirror what happened in the Imperial Irrigation District’s service area. In 2016, the district — the third largest public power provider in California — moved away from net metering in favor of a system similar to what NERA proposes.

IID says its pricing setup, called “net billing,” is fairer than net metering and points to the district’s consistently low electricity rates.

But IID data analyzed…