Georgia Power to convert 96MW coal plant to biomass

Georgia Power has initiated a process to ask the Georgia Public Service Commission (PSC) for approval to convert its coal-fueled Plant Mitchell to renewable wood biomass. Upon conversion, the plant would be capable of producing 96 megawatts of renewable energy, enough electricity to power 60,000 homes.

The fuel switch would result in lower emissions, and would make the plant into one of the largest wood biomass power projects in the United States. It would also have lower fuel and operating costs when compared to continued operation using coal, thereby making the plant more cost-effective for customers.

Surplus wood fuel for Plant Mitchell would come from suppliers operating within an approximately 100-mile (160km) radius of the plant.

By converting Plant Mitchell to biomass, we hope to not only help grow the renewable resource base in Georgia but also to expand the market for renewable energy credits, which ultimately will foster additional renewable energy development. - Mike Garrett, Georgia Power president and CEO

Renewable energy credits are created when a renewable energy facility generates electricity or uses renewable fuel. The PSC is expected to rule on the proposal to convert Plant Mitchell to biomass by spring of 2009. Retrofit construction would begin by spring of 2011 and the biomass plant would likely begin operations in June 2012:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: fuel-switching :: coal :: co-firing :: torrefaction ::

Georgia Power is the largest subsidiary of Southern Company, one of the nation's largest generators of electricity. The company is an investor-owned, tax-paying utility with rates well below the national average. Georgia Power serves 2.3 million customers in all but four of Georgia's 159 counties.

Co-firing and torrefaction
Turning a coal plant into a biomass plant requires a relatively large investment, because key components of the facility will have to be replaced and retrofitted.

However, a new trend in Europe is to make the conversion easier by investing in the transformation of the biomass fuels themselves. Currently, raw biomass can be co-fired with coal, at rates of maximum 10 to 15%. But when the biomass is first torrefied, coal can be entirely substituted with biomass, for the full 100%, and used in the existing plant.

Torrefied biomass has many advantages over raw biomass: the fuel is hydrophobic, is easy to grind, and has a higher energy density meaning it can be transported over much longer distances. These advantages imply that all existing coal infrastructures - logistical and storage facilities, milling and firing infrastructures - can be used as is.

Torrefaction is a relatively new technology in the biomass sector. So far, there is only one large plant in operation. This facility, operated by Topell, is located in Rotterdam, The Netherlands, and produces several hundred thousands of tonnes of torrefied biomass per annum, for use in existing coal plants.

References:
Georgia Power: Georgia Power Seeks Approval for Coal Plant Conversion to Biomass - August 22, 2008.

Biopact: Torrefaction gives biomass a 20% energy boost, makes logistics far more efficient - July 25, 2008

Biopact: Dutch partners agree to build commercial scale biomass torrefaction plant - November 12, 2007

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