Noblehurst Green Energy owns an anaerobic digester system adjacent to the Noblehurst Farms dairy complex. The complete mix digester system is designed by EnviTec Biogas, a Germany-based provider of on-farm biogas systems. The Noblehurst digester is the second EnviTec installation in the U.S., the first being a system at Lawnhurst Farms in Stanley, New York.
The system is designed to receive three different types of substrates. It all starts with manure from the Noblehurst dairy cows, which serves as the base volume of material to the tune of approximately 40,000 gallons per day. Adjacent to the digester is a 42,000 gallon holding tank for liquid food waste. Substrates are conveyed directly from an adjacent dairy processing plant and trucked in from local food manufacturing customers. Also built into the system is a storage pad and conveyor for food scraps and other pre-consumer organics. That material is brought in by Natural Upcycling five days per week. All of the substrates are received and conveyed into the EnviTec pre-mixing system, which consists of a fully instrumented indoor agitation tank that feeds a specific recipe/mixture into the digester.
The digester itself is a circular vessel that is sized to continuously stir 1.33 million gallons of material at a mesophilic design temperature of approximately 100-104 degrees. The microorganisms in the digester break down the substrates anaerobically (in the absence of oxygen), a process which creates biogas. The biogas is then conveyed to combined heat and power (CHP) system designed by Martin Machinery. The CHP is powered by a Guascor HGM 240 engine, and will be intertwined with a generator head that will be capable of producing up to 440 kW. The system is interconnected with the utility provider’s (National Grid) power line infrastructure that runs in front of the complex. This power will be “net-metered”, such that each kWh of electricity produced by the CHP can be offset by each kWh of electricity consumption on-site. At maximum output, the total electricity output is projected to be enough to power the equivalent of more than 300 homes.
By re-investing in the conversion of methane gas to renewable energy, Noblehurst Green Energy is further strengthening Noblehurst Farms’ commitment to agricultural resource stewardship.