Fuel cell power plants transform agricultural waste disposal challenges into economical, environmentally friendly energy solutions
Agriculture operations generate biomass that must be disposed of in an environmentally friendly and economical manner. Anaerobic digesters can reduce the scale of the biomass by a factor of ten, significantly reducing tipping or disposal fees; however, the digestion process generates methane, or biogas, a harmful greenhouse gas. The biogas can be flared but the flaring process generates pollutants such as nitric oxide (NOx), which creates smog, and flaring wastes a potential fuel source.
Fuel flexible Direct FuelCell® (DFC®) power plants can utilize renewable biogas from agriculture operations to generate power on-site in an economical, highly efficient and sustainable cycle, or “loop.” Methane produced in the anaerobic digester is utilized by the fuel cell to generate electrical power for agriculture operations or other uses. Concurrently, high quality heat from the fuel cell power plant heats the sludge in the digester to facilitate the anaerobic digestion process, which in turn produces the methane utilized by the power plant.
Referred to as combined heat and power (CHP) applications, processes like these can result in system efficiencies of up to 90 percent, depending on the specific application.
Because biogas is a renewable energy source, most jurisdictions and governments classify power generation from biogas as carbon-neutral. In addition to being an environmentally friendly method of generating power, fuel cells operating on biogas help agriculture operations reach their sustainability goals in three ways, by:
- Generating power that is virtually absent of pollutants
- Producing electricity in an environmentally responsible manner classified as carbon-neutral power generation
- Generating both power and heat from the same unit of fuel, which reduces or even eliminates the need to generate heat from a combustion-based boiler
Megawatt-class stationary fuel cell power plants require a 300 – 500 scfm1 daily flow of digester gas. Generating this minimum level of digester gas output requires either large agriculture operations such as expansive farms, or ranches with about 3,000 head of cattle, for example; or the aggregation of biomass from multiple farms or ranches in a central location.
The volume of the digester gas produced can vary during the day and seasonally. FuelCell Energy has expertise with automatically blending the digester gas with natural gas as needed, ensuring a consistent and reliable supply of power.
The baseload requirement of 1.4 megawatts for a DFC1500 are about 11 million kilowatt hours (kWh) annually. Smaller agriculture operations may not be able to utilize the full output of the power plant, , necessitating some type of Feed-in Tariff or Net Metering structure with the local electric utility, to achieve optimum system economics.
FuelCell Energy’s executives and engineers work closely with officials at the local, state and national level on environmental and energy policy. We can provide guidance for those interested in utilizing our ultra-clean and efficient fuel cell power plant technology in their individual applications and regions.
For further information, we recommend you contact a FuelCell Energy Sales professional to discuss your operation’s individual energy requirements and environmental objectives.
1 Standard cubic feet per minute