Solar energy advocates blasted Xcel Energy's plan to change the way users pay for electricity at a Public Utilities Commission hearing in Denver on Thursday.

The plan would include a sizable fee increase for solar customers of the state's biggest utility.

Xcel Energy says it needs to separate out the cost of distributing electricity as more solar customers come on to the grid. A grid charge for customers would range from $3 to $45 a month, depending on use.

Company spokesman Mark Stutz said right now, non-solar users are subsidizing the grid costs of solar customers when they’re pushing energy onto the grid and drawing energy when the sun isn’t shining.

“For non-rooftop solar customers, you will basically not see any significant difference to your bill," Stutz said. 

Solar customers say they’re being unfairly singled out. 

“Xcel’s proposals seem designed to limit competition and customer choice,” said Chris Hoffman, an Xcel Energy customer in Boulder who owns solar panels.

Industry members said the change would confuse ratepayers about the benefits of solar. 

"It is likely going to cause enough fear, uncertainty and doubt to prevent them from going solar," Erik Bruner, with the solar company Sunrun, said at a state Capitol rally before the hearing.

The proposal is supported by many business groups, including the Denver Metro Chamber of Commerce. A final decision is expected by the end of the year.