Environmental and solar groups claimed victory Wednesday over a Southwest power company that tried to push up rates for customers who use rooftop solar panels.

The New Mexico Public Regulation Commission approved a settlement between solar customer advocates and a subsidiary of Minnesota-based utility giant Xcel Energy that would cap the fees the company can charge customers with solar panels.

Under the settlement agreement, Southwestern Public Service Co.'s "solar surcharge" will be stopped or reduced, the environmental groups said.

The solar charge was first imposed in 2011. But in October 2015, the utility proposed to increase it by 31 percent for homeowners and as much as 48 percent for businesses.

"We applaud the commission for today's decision, which will prevent [Southwestern Public Service] from further penalizing solar customers for generating their own electricity, an investment that lowers energy costs, supports local jobs and improves health for families statewide," said Rick Gilliam, program director for the solar advocacy group Vote Solar.

The decision "should send a clear signal to utilities around the country that are attempting to impose similar discriminatory fees that this tactic to curtail rooftop solar is as unconstructive as it is unfair," he said.

Xcel Energy did not respond to a request for comment on Wednesday's decision.

But on its website the company points out that it is ranked by a solar energy trade group as one of the top 10 U.S. utilities for advancing solar energy capacity. It says it has helped more than 31,000 customers install solar panels in New Mexico, Colorado and Minnesota. "We're excited to continue to expand the use of solar power in the most economical way for all customers," it says.

Environmental lawyers with the national group Earthjustice, with consumer advocates and Vote Solar, pushed for the settlement, which they said is illustrative of a national trend by for-profit utilities to make it tougher for home owners and businesses to shift to solar energy. Other big solar states such as Nevada are experiencing similar battles over increased fees for using solar and less money for selling their excess renewable energy onto the utility-owned grid.

"Utilities around the country have tried to restrict the growth of rooftop solar by implementing unreasonable and discriminatory fees, surcharges and other rate changes," the group said Wednesday. "In the [Southwestern Public Service] case, the utility sought a large and unsupported rate hike that would have threatened the sustainable growth of distributed solar and other clean energy resources in Southeastern New Mexico."

The groups said last year the state's two other investor-owned utilities also tried to impose new fees on customers with solar panels, which were defeated.

Earthjustice attorney Sara Gersen said New Mexico is a "sunny" place with the "potential to be a solar energy leader." She is glad that the groups were able to stop charges from rising on clean, local energy.

"We want everyone to have a real opportunity to go solar," she said. "We can't let utility fees put clean energy out of reach."