The issue
The Energy Policy Act of 2005 defines biomass as non-hazardous cellulosic material from forest-related resources, wood waste materials excluding solid municipal waste, agricultural waste and plants grown for the purpose of producing electricity. These materials are used to generate power either by burning them or by burning methane released during their decomposition.
The use of biomass to generate energy is called biopower. Biopower is classified as renewable energy because the biomass used to generate biopower is replenishable. Biopower is considered to be carbon neutral because the carbon absorbed by the plant source during its life approximately equals the carbon released when the source is converted to biopower. In addition to being carbon neutral, biopower is generated with lower emissions than power generated by burning fossil fuels.
Types of biomass
The Energy Information Administration (EIA) classifies biopower based on four sources of biomass: landfill gas, municipal solid waste, power from wood and wood derived fuels and other biomass. The other biomass classification includes agricultural byproducts and crops grown to produce biopower. According to the EIA, wood and wood derived fuels account for the largest share of biopower generated by electric utilities.
Net Generation from Biomass by Segment
Source: U.S. Energy Information Administration
Generating biopower
The primary way utilities generate biopower is by co-firing biomass with a fossil fuel such as coal to create steam and power a turbine. Biomass can also be burned as a sole fuel source.
Combined heat and power (CHP)
As identified in the chart above, biomass is used by industrial combined heat and power plants more than it is used for utility power generation. Often, the byproducts of industrial and agricultural processes are harvested at the source site for conversion into both heat and electricity.
U.S. Net Generation from Biomass
Source: U.S. Energy Information Administration
Disadvantages
Burning biomass does present some unique disadvantages. The source may not always be available when needed or at a price per BTU that is comparable to a fossil fuel source. In addition, the biomass may contain characteristics that require boiler modifications and/or additional air permits.
AEP position
From 2001 to 2004, AEP tested biomass co-firing at its Picway plant. In February 2010, AEP Ohio initiated a request for proposals in order to obtain a sustainable source of biomass to be used for co-firing purposes at its Picway, Muskingum River and Conesville plants. AEP has additional tests planned in order to meet the renewable requirements in Ohio.
