Las Gallinas Valley Biogas Energy Recovery System (BERS) Project
Demonstrating a bioenergy system that converts biogas into renewable heat, power, and vehicle fuel.
Las Gallinas Valley Sanitary District
Recipient
San Rafael, CA
Recipient Location
2nd
Senate District
12th
Assembly District
$999,070
Amount Spent
Completed
Project Status
Project Result
Construction of the Biogas Energy Recovery System is complete, and includes installation of the gas cleanup system, microturbines, hydronic boiler, and refueling station. Initial system startup was delayed due to required digester upgrades at the wastewater treatment facility. The gas cleanup system and microturbines commenced operation in December 2017, while the hydronic boiler and refueling station commenced operation in the summer of 2018. Data collection occurred until the end of 2018 and resulted in nearly $70,000 savings from displaced electricity purchases and reductions of more than 8 tons of NOx annually.
The Issue
Wastewater treatment facilities are energy-intensive to operate and produce greenhouse gas emissions and residuals that are costly to manage. The potential to generate renewable energy for the mesophilic anaerobic digestion of wastewater sludge at facilities is significant. However, due to barriers – mainly cost – most facilities flare the gas produced from daily operations and do not utilize it as a source of renewable energy.
Project Innovation
This project installed and operated a pre-commercial biogas energy recovery system (BERS) that converted biogas from a wastewater treatment plant into conditioned digester gas for combined heat and power generation and renewable compressed natural gas for use as transportation fuel.
Project Benefits
The BERS is a first-of-its-kind demonstration of combined heat and power and vehicle refueling at a wastewater treatment plant, and serves as a reference demonstration for the industry. In addition, the Las Gallinas Valley Sanitary District is a small wastewater treatment plant, where economics are often less favorable due to scale dependency of the equipment. Demonstrating economical operation at small-scale proves that wastewater treatment plants small and large could install a similar system. In addition, the BERS provides local benefits to the community and environment by leveraging a renewable fuel stream to produce power and vehicle fuel while reducing local pollutants and greenhouse gas emissions.
Affordability
This project reduces operating costs for the wastewater treatment facility while also reducing the demand on non-renewable natural gas supplies. Conservative operational cost savings are over $100,000 per year.
Environmental Sustainability
The BERS and natural gas fueled vehicles significantly reduce emissions compared to the out-of-compliance internal combustion engine and diesel fueled vehicles which were replaced. For example, estimated NOx reductions are over 1400 grams per megawatt-hour.
Reliability
The BERS converts 30 standard cubic feet per minute of biogas into approximately 130 kW of renewable electricity, 145,000 BTU/hr of heat, and 10,000 diesel gallons equivalent per year of fuel. The wastewater treatment plant provides all biogas required to operate the BERS. By eliminating the need for external natural gas supplies, the project provides energy stability to the wastewater treatment plant and reduces the load and demand from the grid leading to greater grid reliability.
Key Project Members
Michael Cortez
Subrecipients
Western Water Constructors, Inc
Cornerstone Environmental Group, LLC
Match Partners
Las Gallinas Valley Sanitary District
