St. Paul Cogeneration is a biomass-fired combined heat and power (CHP) plant that has increased the fuel efficiency and effectiveness of the District Energy St. Paul’s hot water district energy system and provided an environmentally sound energy source to the local electric provider as well as the heating customers. Ever-Green Energy co-owns this facility with DTE Thermal, and serves as the operator and manager. Ever-Green Energy oversaw the design and construction of the facility, completed in 2003. The plant simultaneously produces up to 65 megawatts of heat and approximately 33 megawatts of electricity. Up to 25 megawatts of this renewable electricity and 153,000 megawatt-hours are supplied to the local electric utility, enough electric supply for up to 20,000 homes. The excess thermal energy supplies enough hot water for approximately 65% of District Energy’s heating needs for its 31.8 million square feet of customer service territory.
Urban wood waste is the primary biomass source for the CHP plant with approximately 1,000 tons of wood chips delivered each day, averaging 250,000 tons annually. Natural gas is mixed with the wood chips in the boiler to increase the combustion temperature and add stability. The biomass is processed by Ever-Green Energy company affiliate Environmental Wood Supply, also co-owned by DTE Energy Resources through its subsidiary DTE St. Paul, LLC. The wood waste comes with storm-damaged or compromised trees, tree trimming, residential waste, habitat restoration, and other processing that leaves behind a low-grade wood by-product. Using biomass and CHP together significantly cuts air emissions and reduces greenhouse gases.
- 2003 system start-up
Technologies implemented: Combined heat and power, biomass
- Heat 65 MW
- Electricity 33 MW
- Provided to local electric utility 25 MW
- Utilizes 250,000 tons of biomass annual supplied by Environmental Wood Supply
- Enables District Energy St. Paul to avoid 100,000 tons of carbon each year