A young woman of 23 is helping to turn pizza crusts, leftover lasagna, and other food waste into methane gas to fuel electric generators at an alternative energy start-up that is transforming the way North America manages organic materials.

At its Waltham plant, Harvest Power uses airtight reactors to allow plant and animal wastes to decompose and produce biogas and other useful products, such as fertilizer.

"We are basically creating a facility where bacteria happily feed on waste and produce lots of useful bioproducts,' said Molly Bales who also researches and develops composting facilities for municipalities, colleges, military bases, stores, and even theme parks.

Harvest Power owns and operates facilities that produce renewable energy, soil and mulch products from organic materials across North America in British Columbia, Ontario, California and throughout the Mid-Atlantic, Midwest and Northeastern states.

The company is building North America's first commercial-scale high solids anaerobic digestion facility at its site in the Metro Vancouver region of British Columbia.

(READ Molly's story in the Boston Globe)