Residents in Orange County are learning how citrus peels, lawn clippings — even chicken bones — have a second life as a clean energy source.

Six months ago, the sanitary district serving Costa Mesa started asking residents to separate kitchen scraps and yard waste so the materials could help make fuel.

The Orange County Register newspaper reports (http://tinyurl.com/gv673nv ) that it's the first such program in Southern California, and the response has been strong.

So far, more than 7 million pounds of material that otherwise would have gone to a landfill has been recycled. It's trucked to a compost pile and, starting next month will be fed into a machine that turns it into clean-burning biogas.

That gas will be used to power the trucks that hauled the waste.