100 percent biomass or bust gains ground

By Anna Austin
Power providers have taken a keen interest in biomass due to its current cost competitiveness with coal and its clean-burning properties. Despite the new-found popularity, not every biomass power project gets the green light. The determining factor for whether a project moves forward or falls between the cracks is the amount of biomass being used-100 percent versus cofired. Lately, the sentiment seems to be all or nothing.

In mid-March, the Georgia Public Service Commission approved Southern Co.'s largest utilities provider Georgia Power's plan to convert its 164-megawatt coal-fired power Plant Mitchell Unit 3, located near Albany, Ga., to a 96-megawatt, 100-percent wood-fired biomass plant. Once completed, it will be the largest operating woody biomass-fired power plant in the U.S.

"Georgia Power has indicated in its filing that conversion of the Plant Mitchell Unit 3 is consistent with the company's renewable expansion plans, adds to fuel diversity and maximizes the life and value of the unit," the GPSC said in a statement. "As part of the 2007 Integrated Resources Plan, the commission found Georgia Power's plan to develop cost-effective renewable resources to be effective."

Under the Integrated Resource Plan statute, new power generation cannot be added to the system nor can significant changes be made to the capacity of an existing facility without a Certificate of Public Convenience and Necessity issued by the GPSC.

The next step in the conversion process is for Georgia Power to obtain an air permit from the state Environmental Protection Division, which could take 15 to 18 months. The company plans to begin the transition in 2011 and bring the plant on line prior to the summer of 2012.

Upon project completion, Georgia Power expects to create 50 to 75 new jobs related to waste wood recovery.

The approval of Plant Mitchell's conversion comes on the heels of the cancellation of Alliant Energy Corp. subsidiary Interstate Power and Light Co.'s proposed 649-megawatt Sutherland Generating Station Unit 4 in Marshalltown, Iowa.

Alliant Energy said it intended to cofire the plant with biomass, such as switchgrass or corn stover. The company estimated it would burn 110,000 tons of biomass annually at the generating station.

A combination of factors led to the cancellation of Alliant Energy's proposal, including the current economic and financial climate, increasing environmental, legislative and regulatory uncertainty regarding regulation of future greenhouse gas emissions, and the terms placed on the proposed power plant by regulators, according to Alliant Energy.

In November, the company's proposal for a similar cofired plant in Cassville, Wis., was shot down by the Public Service Commission of Wisconsin, marking the first time in state history that a coal plant proposal was rejected by state regulators.

Commenting on the cancellation of both Alliant Energy projects, Peter Taglia, staff scientist at Clean Energy Wisconsin, said he thinks it is a great thing to move away from coal and biomass proposals that are not focused on biomass. "In the aftermath of Wisconsin's rejection of the coal plant proposed in Cassville, Xcel Energy has brought forward an application to convert a coal plant in Ashland, Wis., to 100 percent biomass via gasification," he said.

The Bay Front Power Plant project, estimated at $58 million, will require additional biomass receiving and handling facilities at the plant, an external gasifier, minor modifications to the plant's remaining coal-fired boiler and an enhanced air quality control system.

Xcel submitted its application to the PSCW at the end of February. Following all state regulatory approvals, engineering and design work is expected to begin in 2010, and the unit could be operational by late 2012.