Xcel Energy is seeking to change that by proposing a rate increase for solar customers that the state's largest power supplier said pays for providing electricity in case those homes need it.
Xcel is proposing a 2.6 cents per kilowatt hour fee based on the generating capacity of a home's solar panels.
The proposed fee would be along with actual electricity used and a $7 to $8 service fee now charged to cover meter reading and billing.
Current solar customers would be exempt.
The Public Utilities Commission will hold a hearing on Xcel's proposed fee on August 5.
Members of the solar panel industry oppose the fee, saying homeowners installing solar panels allow Xcel to add carbon-free energy while using existing infrastructure, saving the company money on construction and transmission lines.
They say installing panels also helps Xcel meet a state mandate that the company generate 20 percent of its power from renewable sources by 2020.
"It's going to have a tremendously negative effect on the solar industry in Colorado if Xcel's proposal is approved," Blake Jones, president of Namaste Solar in Boulder told the Daily Camera. "Solar-system owners are actually providing a benefit to the utility, to the grid and to other rate payers."
Solar customers are net-metered, which means they receive credit for excess electricity produced by the solar panels that flows into Xcel's power grid.
Jones said Xcel could become the first utility to charge net-metered solar customers a fee for having access to electricity in the grid.
"This is something that's not happening anywhere in the country," Jones said. "This is not a good thing. This is not part of the vision we have for Colorado's new energy economy."
Xcel spokesman Tom Henley defended the proposed hike.
"We have to build the system so the customer can use as much energy as they want," Xcel spokesman Tom Henley said. "Right now, solar customers have this backup to the grid for free."