October 9, 2008
WOOD-BURNING POWER PLANTS
By: Paul Frisman, Principal Analyst
You asked about wood-burning power plants.
Wood fuel is included in the larger category of biomass fuels, and is considered a renewable fuel source. According to the California Biomass Energy Alliance website, there were about 80 operating biomass plants operating in 19 states in 2003, representing about 1,676 megawatts (MW) of generating capacity nationally.
There is one small (10 kilowatt) wood-burning plant in Connecticut. Three more have been proposed. The proposed plants would be in Bozrah, Plainfield, and Watertown and generate 29, 37.5, and 30 MW of electricity, respectively. (Conventional power plants typically generate between 500 and 1,000 MW). The three proposed plants have been reviewed by state regulators and are now seeking local approvals.
State law requires electricity providers to obtain a minimum percentage of their power from renewable energy sources, which can include biomass. For information on hydropower, another renewable energy source, please see OLR Reports 2006-R-0566, 2007-R-0429 and 2008-R-0033.
WOOD AS A FUEL SOURCE
Wood fuel, in the form of wood chips, forest waste, land-clearing debris, and construction and demolition (C&D) waste, is the most common form of biomass, or renewable fuel derived from plants. Biomass is a renewable fuel source because new trees or plants can be grown to replace the biomass consumed as fuel.
Wood-burning plants either burn wood to produce steam to power a turbine generator, or use a “gasification” process in which wood is heated at high temperatures to produce a gas which then can be burned to produce electricity.
According to a 2000 study, “Biomass Strategies for Connecticut,” (http://www.ctcleanenergy.com/documents/Biomass_Report_from_J_Gordes.pdf) there is an estimated 100 to 300 MW of electric generation potential available from biomass in Connecticut. Connecticut wood sources include land clearing and C&D debris, and fuel harvested from state forests. According to the above report, a 1990 study found that forest harvesting of 219,000 tons a year could occur on a long-term sustained yield basis in Connecticut.
ELECTRICITY GENERATED FROM BIOMASS
According to the California Biomass Energy Alliance website (http://www.calbiomass.org/), there were about 80 operating biomass plants operating in 19 states in 2003, representing about 1,676 MW of generating capacity. California had the most plants, 29, with generating capacity of 588 MW.
The U.S. Department of Energy (DOE) states that renewable energy sources (excluding hydropower) produced 2.5% of the nation's net electricity generation in 2007. Slightly more than half of this amount (53%) was from biomass. Wood and wood-derived fuel accounted for 38,649 million kilowatt hours (kWh) of the 54,758 million kWh of electricity generated nationwide from biomass in 2006, or about 70%.
According to the Independent System Operator—New England (ISO-NE), responsible for the transmission of electricity in New England, there are about two dozen generating facilities that primarily burn wood in New England, including a 10-kilowatt wood-burning facility that heats greenhouses and produces electricity for Pinchbeck Roses in Guilford. (One thousand kilowatts equal one megawatt).
CONNECTICUT RENEWABLE FUEL REQUIREMENTS AND PROGRAMS
Renewable Portfolio Standard (RPS)
The RPS requires electricity providers to obtain a minimum percentage of their power from renewable energy sources, including biomass. The percentage increases from a total of 10% in 2008 to 27% in 2020 (CGS § 16-245a).
By law, there are three classes of eligible renewable fuel sources, and electricity providers must obtain a certain percentage of their energy from each. Class I includes, among other fuel types, sustainable biomass facilities that meet certain nitrogen oxide emission rates. (Sustainable biomass excludes C&D waste, except in certain instances). Class II sources include certain other biomass facilities (CGS § 16-1 (a) (26), (27) and (45)).
The law required electric distribution companies to enter into minimum 10-year contracts for at least 150 MW of class I renewable power by July 1, 2008 (CGS § 16-244c (j) (2)). According to the Connecticut Clean Energy Fund (CCEF), which promotes investment in, and growth of, renewable energy sources, three wood-burning projects in this program have been reviewed by CCEF and the Department of Public Utility Control, and are now acquiring state and local approvals and permits. The proposed facilities are in Bozrah, Plainfield, and Watertown.
PROPOSED CONNECTICUT WOOD BURNING PLANTS
Clearview Renewable Energy, LLC, is proposing a 29 MW mixed biomass heat and power project to be located on a 31–acre site at the 259-acre Kofkoff Egg Farm in Bozrah. The facility would process 1,112 tons of clean wood waste and 340 tons of poultry manure a day.
Plainfield Renewable Energy, LLC is proposing to build a 37.5 MW wood-burning project on a 27-acre parcel in Plainfield. It would process about 365,000 tons of wood fuel a year. The fuel would be comprised of wood waste, including forest scrap and land clearing waste, other waste wood, and separated C&D waste.
Tamarack Energy, Inc. has proposed a 30 MW biomass project on a 33-acre site in Watertown to convert clean wood chips to electricity. It will sell 15 MW of this capacity to Connecticut Light & Power; the balance to ISO-NE. It would use about 360,000 tons of wood fuel annually from local forest management, land conversion, and wood processing operations.
More information on wood burning plants can be found on the DOE Energy Information Administration website, at http://www.eia.doe.gov/cneaf/solar.renewables/page/biomass/biomass.html and in the DOE's 2008 Renewable Energy Data Book, available at http://www1.eere.energy.gov/maps_data/pdfs/eere_databook_091208.pdf.
A December 2007 University of Massachusetts report on energy from forest biomass is available on-line at http://www.mass.gov/Eoeea/docs/doer/renewables/biomass/bio-eco-impact-biomass.pdf.
A May 2006 report on emissions from wood fuels derived from C&D waste by the Northeast States for Coordinated Air Use Management (NESCAUM) is available on-line at the NESCAUM website (http://www.nescaum.org/).