Introduction to the San Bernardino Fuel Cell Facility
In July 2021, the San Bernardino Municipal Water Department (SBMWD) commenced operation of a fuel cell facility at the San Bernardino Water Reclamation Plant (WRP) site. The fuel cell allows SBMWD to continue to beneficially consume methane produced from wastewater treatment digesters (“digester gas”) to produce electricity for the WRP.
Historically, the Department used digester gas beneficially to fuel engines that operated generators, aeration blowers, and pumps that were part of the wastewater treatment process. SBMWD must meet several stringent regulations to ensure the health and safety of the community it serves and to protect the environment. This includes new and revised air quality standards for operation of wastewater plants such as the WRP.
The facility was conceived as part of the SBMWD’s ongoing response to the new and revised regulations and supports the SBMWD’s plans to improve operations and continue to beneficially utilize biogas generated from the WRP digesters. The fuel cell facility was developed in a public/private partnership between SBMWD and FuelCell Energy, Inc. (FCEL), a leading US manufacturer of fuel cell power plants with several facilities at wastewater treatment plants in California. FCEL was responsible for construction, installation, commissioning of the entire facility and will also provide long-term operation, maintenance, and service.
As a result of the fuel cell, SBMWD will balance the need to maintain compliance with South Coast Air Quality Management District (SCAQMD) regulations, perform the wastewater treatment function at the most reasonable cost available, and contribute to cleaner air for the region.
The facility is located on the east side of the WRP facility at 399 Chandler Place
The facility employs FCEL’s SureSource® 1500 fuel cell power platform, a certified compliance technology under SCAQMD rules. The facility is designed to receive and process WRP’s digester gas and convert the methane in that gas to 1.4 megawatts of electricity, a quantity sufficient to meet approximately 55% of the anticipated WRP site electricity needs. That electricity is then purchased by the SBMWD at a rate lower than the rate through which the SBMWD can purchase the electricity from the local electric utility agency. The fuel cell also produces heat which is converted to hot water and used by WRP to improve the efficiency of the wastewater treatment digesters.
Fuel Cell Operation on Biogas – Efficient Production of Renewable Electricity
The fuel cell operation at the WRP is outlined in the general diagram below. Wastewater received at the WRP from the City of San Bernardino and surrounding areas is fully treated in compliance with all regulatory permit requirements before discharge to the Santa Ana River. A by-product of the treatment process is the creation of methane gas from decomposing waste. This methane-filled biogas (or digester gas) is generated in the WRP’s anaerobic digesters. WRP sends the biogas (digester gas) to the fuel cell facility via plant piping where FCEL filters the gas, removing impurities, and delivers the biogas (digester gas) to the fuel cell plant. The fuel cell converts the biogas (digester gas) to ultra-clean renewable power and delivers heat back to the digesters to maintain the warm temperature required for proper operation and treatment.
The use of renewable fuel to generate the 1.4 megawatts of electricity at the WRP continues to allow the SBMWD to reduce emissions of carbon dioxide greenhouse gases (GHG) annually to the environment if the digester gas was legally flared to the atmosphere and the necessary purchased power was produced in a natural gas power plant.
Fuel Cell Technology – Clean Energy Without Combustion
A fuel cell electrochemically converts fuel directly to electricity. Each individual fuel cell consists of two electrodes—a negative electrode (or anode) and a positive electrode (or cathode)—sandwiched around an electrolyte. Fuel and water are fed to the anode and air is fed to the cathode. A catalyst at the anode separates hydrogen molecules into protons and electrons, creating a flow of electricity between cathode and anode. The chemical reaction also produces water and heat.
The net result is a direct conversion of fuel energy to electricity without combustion or the harmful pollutants associated with burning fuel. A diagram of a FCEL carbonate fuel cell is provided below.