DWP FINDS IT'S NOT EASY BEING GREEN AUDIT PUSHES DEPARTMENT TOWARD CLEAN-POWER DEAL.

Byline: Kerry Cavanaugh Staff Writer

Hoping to bulk up its meager list of low-polluting, green energy sources, the Los Angeles Department of Water and Power plans to spend $16 million a year to buy electricity from a proposed power plant that turns leaves and yard clippings into energy.

The plant would be the largest of its kind in the country, but Santa Monica-based BioConverter LLC must find a location in the city and get permission to build.

The DWP has agreed to buy power from the BioConverter plant when the facility comes online, expected in 2008. The electricity would serve roughly 40,000 homes. The City Council must approve the agreement.

The utility's Green Power program was chastised in a 2002 audit for spending too much on public relations and not enough on development of clean power. Controller Laura Chick is releasing a new audit of the program in January.

DWP officials said the BioConverter agreement marks a solid increase in green energy and they've locked in a good price for power that is only paid when the electricity is delivered.

``We're highly optimistic the system will work well, but if it doesn't then city and customers aren't affected,'' said Henry Martinez, DWP's chief operating officer for power.

Environmental groups are also enthusiastic about the DWP agreement, calling it a crucial step by the city toward using 20 percent renewable power, such as solar, wind and geothermal sources, by 2017. The city now gets about 2 percent of its power from renewables and 50 percent from high-polluting coal. The DWP hasn't committed to a renewable energy goal yet.

``The idea is a good one,'' said Martin Schlageter, energy advocate with the Coalition for Clean Air. ``It's the kind of renewable energy project that if DWP puts its mind to, we could see a lot more of.''

The BioConverter plant would feed 3,000 tons per day of grass clippings, tree trimmings and leaves into an anaerobic digester - or a chamber where the green materials decompose and give off methane gas. The methane fuels turbines that produce 50 megawatts of electricity. The leftover material is a dark, peat-like compost that can be bagged and sold as fertilizer.

This technology is already common in Europe, where landfill space is scarce and foliage is diverted from most dumps. Anaerobic digesters are becoming more common on California farms to generate gas from animal waste. However, experts said the technology hasn't been used in-state to process green materials.

Green power has traditionally been more expensive than more polluting power sources, but BioConverter chairman Gary Petersen said the plant can offer reasonable electricity rates because the company charges per-tonnage fees for foliage received and has a marketable product at the end.

The city will buy electricity for $48 per megawatt hour. A modern natural gas power plant runs between $35 to $50 per megawatt hour. Wind power costs between $45 and $55 per megawatt hour.

The BioConverter project is the second of three renewable energy projects the DWP is developing. The utility will spend $162 million to install wind-powered turbines near Mojave. The wind-power project will generate power for 100,000 homes.

The DWP is also pursuing geothermal power production, in which underground pockets of hot water or steam are harnessed to fuel turbines and generate electricity.

Kerry Cavanaugh, [phone]

kerry.cavanaugh(at)dailynews.com