Skip navigation
Tribal Energy and Environmental Information Clearinghouse
Tribal Energy and Environmental Information Clearinghouse: Environmental resources for tribal energy development
Energy Resources Assessments & Monitoring Laws & Regulations
Energy Resources Assessments & Monitoring Laws & Regulations |  Home  |  News  |  FAQ  |  Glossary
Document Library
Federal and Tribal Contacts

Biomass Energy Operations: Resource Requirements and Impact Sources

Minimal land-disturbing activities are anticipated during the operations phase. Operations would result in impacts to other resources, including air, water, visual resources, and local transportation.

Minimal land-disturbing activities are anticipated during the operations phase, except at an active landfill that is still accepting and burying waste. Routine operations at a biomass power plant include receiving, storing, and processing fuel, and combustion to produce steam for use in manufacturing processes or to produce electricity. A biofuels facility also receives, stores, and processes the biomass for production of ethanol, biodiesel, or biogas via some combination of fermentation, pyrolysis, catalytic conversion, distillation, removal of contaminants, storage, and transport.

The following factors could affect whether an environmental impact could occur at a biomass energy facility and whether it would be considered an adverse effect.

  • Acreage — The footprint of a typical biomass energy production facility ranges from 10 to 100 acres.
  • Emissions — Operation of some biomass plants would result in emissions of criteria air pollutants and hazardous air pollutants from combustion, but these emissions would be managed to meet air quality standards. Dust suppression technologies would be used to manage the risk of dust emissions. Other emissions would include pollutants from the operation of vehicles and the periodic operation of diesel-fueled emergency generators for preventive maintenance purposes; fugitive dust from vehicle travel on unpaved roads or wind erosion from gravel surfaces; and minor release of volatile organic compounds from on-site storage of various chemicals used for operation, maintenance, and cleaning.
  • Waste Generation — Direct combustion of biomass in a biomass power plant would produce ash that would be collected and removed to a landfill or sold for other uses. Ash from a biomass power plant using municipal solid waste as its fuel could contain hazardous constituents (and need to be handled as a hazardous waste) if the municipal waste stream included minor amounts of hazardous materials or wastes.

    At a biofuels plant, all of the biomass received as feedstock would be converted to biofuels and commercially valuable by-products, such as glycerin sold for other industrial uses, solids from fermented mash sold for animal feed, and liquids and fiber from waste digesters sold for use as fertilizer and soil enhancement. Any hazardous waste would be disposed of via an authorized contractor to an approved site. Other wastes generated would include small amounts of gear oil and lubricating oils, transmission and glycol-based coolants and lubricants, and paints or coatings for corrosion control.
  • Water Needs — A biomass power plant would require a cooling water system to condense steam that was produced in the boiler and used to drive a turbine-generator. This is typically the largest consumptive use of water at any thermoelectric power plant (i.e., power plants that generate steam to drive turbines to produce electricity).

    The amount of water needed to support a biomass power plant is determined primarily by the power generating capacity of the plant, the steam requirements, and thermal efficiency of the steam turbines used. Ambient conditions of temperature and humidity also affect the heat removal capacity of cooling systems which, in turn, can also affect the amount of water required to support their operation.

    By far, the greatest amount of water is consumed in the operation of a once-through cooling system and water flows ranging from 400 to 700 gallons per minute are often required for each megawatt of power being produced. Once through systems are not practical except when the power plant is located adjacent to a very large body of water. The great majority of thermoelectric power plants use a closed loop cooling system.

    Evaporative wet cooling systems require continuous additions of a small amount of additional water to replace water lost to evaporation (usually about 2% of the total volume of water in the recirculating system) and to replace water purposely removed from the system (blowdown) discharged (usually another 2% of the total volume); water consumption of these systems can range from 10 to 15 gallons per minute for each megawatt of electricity produced. Dry cooling systems do not require water since the steam condensate is cooled by exchanging its heat with the ambient air flowing over the surface of an air-cooled condenser.

    Up to 400 gallons per minute (gpm) of water could be required for operation of a biofuel facility. Part of this water would be evaporated, part incorporated into the plant by-products, and the rest discharged as wastewater. An algae-based biodiesel facility requires water to support algal growth. The volume of water required is determined by the size of the facility. However, because the water is largely replenished only to replace minor amounts of water lost to evaporation, it is likely that algae biofuel facilities would use less water than other biofuels facilities, should they prove to be commercially viable.

    A biogas waste digester system for municipal waste sludge would typically require about 30,000 gallons per day of water in addition to the more than 100,000 gallons per day contained in the sludge feedstock.

    A biogas digester for animal manure recycles most of the water used and requires very little additional water.

    A landfill biogas facility also would use very little water.

    Small amounts of water would be needed for routine cleaning and periodic replacement of glycol-based coolants.

    Potable water would be required for the operations and maintenance workforce.
  • Workforce — Power-generating plants and other biofuels plants would require on the order of 30 to 235 personal for 24-hour operation. Farm-based or municipal waste biogas plants require few personnel during the operations phase.
  • Utility and Emergency Power Requirements — Biomass power plants would use energy produced at the plant. Ethanol and biodiesel plants would utilize local utilities to meet power requirements. Biogas plants normally use energy produced at the plant. Water would be obtained from a local utility, from groundwater on site, or from a surface water body. A diesel-fueled generator would typically produce emergency power.