Before the first customer was served in 1983 District Energy imagined combined heat and power (CHP) in its future plans. CHP is one of the most efficient energy generation technologies in the world. And District Energy has been using this technology to generate both heat and power for over 20 years.
In 1990, the first CHP system was installed to help boost production efficiency at and to generate power for the plant. That was just the beginning. Planning continued for building a biomass-powered CHP, or cogeneration system. The dream was to produce renewable heat for our customers and electricity for export to the grid. In 2003, this dream became a reality when St. Paul Cogeneration came online. Now the majority of the heat delivered to our customers is produced from clean local woody biomass and forest residuals.
Each year we try to push the envelope to use more renewable fuels and less fossil fuel. We reached another system best by frequently cofiring 20% wood chips by volume with coal during this winter season. Cofiring allows us to use existing coal boilers to combust biomass by blending it with coal.
In addition to cofiring, we achieved for a rate of 85% biomass for the fuel used at St. Paul Cogeneration. Eventually, our goal is to become 100% renewable system-wide using a combination of biomass, solar thermal, heat recovery and efficiency, and other renewable resources. Whatever the future holds, District Energy is dedicated to projects that are reliable, effective, and economically feasible to support our customers.
