Biomass Electric Id Ad 5

Bioresource Technology 46 (1993) 86-9 3 ELECTRICITY FROM BIOMASS IN THE UNITED STATES: STATUS AND FUTURE DIRECTION Richard L . Bai n Industri al Technologies Division, National Renewable Energy Laboratory, 1617 Cole Bird, Golden, Colorado 80401-3393, USA Abstract The biomass power industry in the United States has grown from less than 200 M W in 1979 to more than 6000 M W in 1990, primarily as a result of the Public Utilities Regulatory Policies Act of 1978. The United States Department of Energy (USDOE) is projecting installed capacity will grow to about 22 G W by the year 2010, with environmental considerations (carbon dioxide neutrality, low sulfur dioxide emissions, and low nitrogen oxides emissions) being the primary driving force. The primary conversion technologies being deve- loped in the United States are gasification-combined cycle systems, pyrolysis oil-comb ined cycle systems, and advanced direct combustion systems. The USD OE program has the objective of reducing the risks associated with commercializing new technologies and feed- stocks for power production. The program is divided into two areas: research and development and systems analysis. The major research and development program is in the area of hot-gas cleanup, while the systems analysis area is concentrating on gasifier scale-up and site- specific com mercial feasibility studies. Key words: Alkali deposit, biomass-to-electricity, carbon dioxide, dedicated feedstock supply systems (DFSS), direct-fired turbine, electricity, Energy Policy Act (EPACT) of 1992, gasification, gas turbine, Hawaii biomass gasification facility, hot-gas cleanup, PURPA (Public Utilities Regulatory Policies Act of 1978), pyrolysis, steam turbines, whole tree energy. of capacity (Energy Information Agency, 1989), or about 43% of total generating capacity. The use o f biomass in 1989 was more than 3"5 exajoules (EJ), or about 4"3% of the total USA primary-energy use of about 81 EJ. More than 70% of biomass-based power is produced on a cogeneration basis. Wood-fired systems represent 88% of total capacity, followed by landfill gas at 8%, agricultural wastes at 3%, and anaerobic digesters at 1%. Biomass electric-generating capacity by state is shown in Fig. 1. Biomass power plants use technology that is very similar to that used in coal-fired power plants. For example, biomass plants use similar steam-turbine generators and fuel-delivery systems. However, coal combustion is more mature technology, which is reflected in higher pow er efficiencies. Today's biomass power-plant efficiencies are typically 15-20%, and the best units have efficiencies of about 25%. Electricity costs are in the 6"5-8"5 c/kW h range. The average biomass pow er plant is about 20 megawatts (MW) in size, with a few dedicated wood-fired plants in the 40-50- MW size range. It is estimated that there are nearly 1000 biomass-fired plants in the USA, only a third of which offer electricity for sale. The rest are owned and operated by the paper and wood-products industries for their own use. Meanwhile, mod ern coal-fired pow er plants are larger and have efficiencies of 30-35%. Coal plants achieve higher efficiencies because coal has INTRODUCTION Since 1978, the USA biomass-power industry has installed over 6 gigawatts (GW) (Rader, 1990) of grid- connected generating capacity, much of it associated with the wood and wood-products industry, which obtains more than half of its electricity and thermal energy from biomass. In comparison, coal-fired electric units in the USA account for approximately 297 GW Bioresource Technology 0960-8524/93/S06.00 © 1993 Elsevier Science Publishers Ltd, England. Printed in Great Britain [] 400-1000 MW [] 100-199 MW [ ] 200-399 MW [] Less than 100 MW Fig. 1. Biomass-electric-generation capacity of state, 1989. 86

Biomass Electric Id Ad 5

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