California Coal Plant Turning To Biomass

On a global scale, coal isn’t going away — the just-released World Energy Outlook 2010 forecasts that China will increase its coal-fired generating capacity by 600 gigawatts over the next quarter-century. But in developed countries reliance on the cheap-but-dirty fossil fuel is expected to decline, and the fate of the Mt. Poso plant 15 miles north of Bakersfield, Calif., tells part of the story of how it’s happening.

DTE Energy Services, after acquiring a “significant interest” in the plant, says it will convert the plant to 100 percent woody biomass, with the fuel derived from “urban wood waste, tree trimmings and agricultural residues.”

Mt. Poso Cogneration Plant, Bakersfield, California

image via Mt. Poso Cogeneration Company

Mt. Poso was opened in 1989 with a coal-fired generating capacity of 49.5 megawatts (MW). The plant currently operates on a blend of coal, petroleum coke and tire-derived fuel. California’s requirement that utilities get an ever-increasing percentage of their power from renewables — by 2020, 33 percent — is now inspiring a complete move away from coal. DTE Energy services said that as a biomass plant, Mt. Posos will produce 44 MW of power, which it will sell to Pacific Gas & Electric.

Utilities like biomass because it qualifies as a renewable, but unlike wind and solar can be produced around the clock. The plants are hardly emissions free, but biomass supporters argue that the carbon it releases is already part of the carbon cycle, so by using it instead of fossil fuels, the carbon in fossil fuels remains locked away. This argument has lost some of its persuasive power after studies have shown that growing biofuels can actually result in the release of additional carbon, both from the soil and from energy inputs. Use of salvaged biomass — such as at Mt. Poso — largely avoids this issue.

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Pete Danko is a writer and editor based in Portland, Oregon. His work has appeared in Breaking Energy, National Geographic's Energy Blog, The New York Times, San Francisco Chronicle and elsewhere.