The 1-MW system will produce both electricity for the bottling lines and hot water for pasteurization. The on-site power system will protect the plant from utility power outages and is expected to pay for itself in energy savings in about two years.

The cogeneration system consists of a natural gas-fired generator and a heat recovery system, to convert waste heat from the electricity generating equipment and exhaust into hot water. The system, which is scheduled for installation in August, will produce approximately 70% of Pokka's electricity and 30% of its hot water requirement.

Once the system is in place, says Northern Power, it will reduce Pokka's annual energy costs by more than $800,000. The system is expected to produce electricity at an average cost of 6 cents per kilowatt-hour, compared to current utility rates of almost 15 cents per kilowatt-hour. By recovering waste heat, the system will also reduce the plant’s boiler gas bill by 25%. In addition, the cogeneration system will help minimize plant downtime and prevent product spoilage resulting from utility power outages.

Due to its waste heat recovery, the system’s overall fuel efficiency will rise to more than 75%, compared to typical efficiencies of 30% to 35% from utility power, Northern Power says. Such increased efficiency will reduce greenhouse gas emissions by up to 45%. These higher fuel efficiencies also qualify Pokka's new system for a $600,000 incentive rebate from the Self-Generation Incentive Program of the California Public Utility Commission (CPUC).

The new system is designed to provide improved power reliability. In the last two years, Pokka has experienced 24 utility power outages and disruptions.

In normal operation, the cogeneration system will run in tandem with the grid. If a power outage occurs, Northern Power’s controls will transfer the plant’s critical operations completely over to the cogeneration system, keeping the facility up and running.

Publication date: 04/29/2002