What customers may not know is that there’s a dirtier side.

While solar is a far less polluting energy source than coal or natural gas, many panel makers are nevertheless grappling with a hazardous waste problem.

State records obtained by The Associated Press show that 17 companies with 44 manufacturing facilities in California produced 46.5 million pounds of hazardous waste from 2007 through the first half of 2011.

Roughly 97 percent of it was taken to in-state waste facilities, but more than 1.4 million pounds was transported out of state, as far away as Rhode Island.