Switching from a black hat to a green hat

By Lisa Gibson
The paradigm shift in converting a coal power plant to biomass is riddled with permitting hurdles, along with technology and logistics issues.

"Going from a black hat to a green hat is hard to do," said Mike Hawkins, president and CEO of Ohio-based Red Hawk Energy LLC, who participated in the Pacific West Biomass Conference & Expo in Sacramento. The company's 52-megawatt coal plant is transitioning to biomass power and should be fully operational with 100 percent biomass in the second quarter of 2011, he said.

In converting, economics of size matter, he said, reiterating the point made by fellow presenter Peter Flynn, a professor in the mechanical engineering department at Canada's University of Alberta. Optimal plant size varies with biomass feedstock availability and processing technology, but is much larger than conventional wisdom suggests, Flynn said. Although larger plants may have longer transportation routes, efficiency in larger plants comes out on top. "Capitol efficiency trumps transportation costs," he said.

In large power plants, coal costs about $4,500 per kilowatt hour, with biomass at about $4,000, Hawkins said. Biomass for a converted coal plant, however, costs only $1,000 per kilowatt hour.

Conversion is challenging and should not be underestimated, Hawkins said. Operating issues include fuel quality, erosion and corrosion, the capacity factor, operations training and fuel handling. Technology issues include a boiler study, unit de-rating, boiler and fuel feed modifications, and fuel receiving and storage. Companies can opt for a basic dump truck and storage system, or take the route Red Hawk Energy took: a state-of-the-art storage facility with dust and fire suppression, Hawkins said.

The plant is currently cofiring 20 percent biomass. Hawkins recommends plants considering conversion perform a detailed fuel study, and analyze the reliability of suppliers and fuel contracts.

He also discussed power purchase agreements, emphasizing the importance of obtaining the terms needed.
Other issues companies will face include lender issues, and development and construction costs. The entire process from start to finish probably will take about three years, Hawkins said.

-Lisa Gibson