In the district energy field, District Energy St. Paul is considered the most notable in the United States for its use of renewable energy sources and implementation of energy conservation measures.
Launched as a demonstration project in 1983, District Energy was Saint Paul’s response to the energy crises of the 1970s. The venture was a public-private partnership between the City of Saint Paul, State of Minnesota, U.S. Department of Energy, and the downtown business community, all of whom believed in the viability of a hot water district heating system to alleviate the pinch of the energy crisis.
District Energy St. Paul was built from the vision of Saint Paul Mayor George Latimer. Led by Mayor Latimer, the City lobbied state and federal governments for assistance in adopting a technology, developed in Europe, that could solve the heating problems of the city. Using the expertise of Hans Nyman, District Energy’s first president, the system was successfully designed to be energy efficient, fuel flexible, and result in stable rates for its customers.
In 1993, ten years after the successful startup of the district heating system, District Energy began offering cooling service to downtown building owners. Ten years later, in 2003, District Energy became a green energy service provider following construction of an affiliated combined heat and power (CHP) plant that is fueled by a renewable resource—clean, urban wood residuals. Using renewable fuel, the CHP plant simultaneously produces about 65 megawatts of thermal energy for District Energy and 25 megawatts of electricity for Xcel Energy. It is the largest wood-fired CHP plant serving a district energy system in the nation.
In 2011, the system was advanced further with the installation of the Midwest’s largest solar installation. It is one of the country’s largest hot water solar projects and the first in the United States to be integrated into a district heating system. The system peaks over 1.2 MW (thermal equivalent) and provides hot water and space heating to the Saint Paul RiverCentre, as well as exporting to serve other District Energy customers.