The Bergen County Utilities Authority (“BCUA”) is a secondary biological wastewater treatment plant with a current process design capacity of 109 MGD located in Little Ferry, New Jersey. The facility has five (5) anaerobic digesters for the primary and secondary sludge.  These digesters produce one (1) million scfd of biogas (digester gas). In addition to the digesters, there is a sludge storage tank, which produces approximately 127,000 scfd of additional biogas. 

Metro Energy Solutions evaluated a number of different options for a cogeneration installation for the plant utilizing excess biogas to generate electricity to offset some of the power that is currently purchased to operate the facility.  Electric power usage at the facility currently averages about 3200 kW.  Based on the electric and thermal loads at the site and the amount of biogas available, Metro Energy recommended the installation of two engine generator sets, each rated at 1500 kW, to offset most of the electric usage.  The engines will be operated primarily on biogas, but natural gas will also be used as a supplementary fuel since the supply of biogas is insufficient to meet all of the needs of the plant.  Maximum recovery will be made of the waste heat from the engines. The new gas engine generators will operate in parallel with the local utility source, therefore, the new generator switchgear will provide a highly reliable source of power, having both the utility and the engine generator connected to it.

Based on the Metro Energy feasibility study the new cogeneration plant will save approximately $26 million over the course of running the plant for 25 years. In addition Metro Energy has applied for incentives and grants under the NJ CleanEnergy program for $1 million to offset the costs of building the plant.