When Jim Bankston installed solar panels on his Tuscaloosa home, he estimated it would trim his electricity bill, and the savings would eventually offset the cost of the hefty investment. After it was running, he noticed fees on his Alabama Power bill that he didn't understand and learned there was a $5-per-kilowatt capacity charge on customers who use solar panels to produce a portion of their own electricity. I am having to pay them just to use the photons that are hitting my own roof," Bankston said. He had estimated the system would eventually pay for itself in 20 years. With the fees included, he said it could be twice that. "It's discouraging the use of solar," said Keith Johnston, managing attorney for the Southern Environmental Law Center's Birmingham office. "We call it a solar tax." The fee is based on the size of the solar system, so a five kilowatt system would have a monthly fee of $25. The average solar panel setup for a home costs about $10,000, according to the environmental law center. The fees add another $9,000 over the 30-year-lifespan of a system, dramatically increasing a homeowner's cost and reducing any financial benefit they see from solar, the law group said. The issue of fees has arisen in New Mexico, Arizona and other states, causing clashes between renewable energy proponents and utilities. A power company in Iowa unsuccessfully pushed lawmakers to approve a fee that would require a homeowner with an average solar array to pay about $27 a month.