Applications

Wastewater

Fuel cell power plants convert municipal waste challenges into ultra-clean energy solutions

Municipal water treatment plants are an ideal application for Direct FuelCell® (DFC®) power plants, which excel at converting waste disposal challenges into value streams of ultra-clean electricity and usable high quality heat.

Many municipalities use anaerobic digesters to efficiently process large volumes of waste water in specialized treatment plants. These municipalities must then dispose of the methane, or biogas, produced by the biomass. A harmful greenhouse gas, methane cannot be released directly into the atmosphere in any significant quantities. The biogas can be flared but the flaring process generates pollutants such as nitric oxide (NOx) and wastes a potential fuel source.

Fuel flexible Direct FuelCell® (DFC®) power plants can utilize renewable biogas from municipal water treatment plants 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 the water treatment plant 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.

1.4 MW fuel cell power plant at a municipal water treatment facility

1.4 MW fuel cell power plant at a water quality control plant in Riverside, California

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 and may offer financial incentives to promote adoption. In addition to being an environmentally friendly method of generating power, fuel cells operating on biogas help municipalities reach their sustainability goals in three ways, by:

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 fuel supply to generate continuous ultra-clean power. Based on our experience, the minimum required daily flow to support the fuel requirements of a megawatt-class fuel cell power plant is 30 million gallons of wastewater.