Solar Thermal

Central Solar Hot Water Systems Design GuideRead more about solar thermal in the Central Solar Hot Water Systems Design Guide.

District Energy St. Paul was the first in the United States to integrate solar thermal into a district heating system.  This technology has been integrated in international systems where district heating systems are more commonly utilized.  The 23,000 square foot system is comprised of 144 flat-plate collectors that can reach temperatures over 200°F.  This allows the system to reach thermal peaks above 1.2 Megawatt and generate approximately 1000 Megawatt-hours of heat each year.  The heat generated is utilized primarily by the host building, the Saint Paul RiverCentre.  Due to fluctuations in the building’s need for space heating and hot water, the solar heat collected can be exported to District Energy’s thermal grid when excess heat is available.  This feature allows the Saint Paul RiverCentre and other District Energy customers to share the solar energy produced by the system and maximize the distribution of energy collected.

How it Works
The solar collectors absorb energy from the sun into a heat transfer fluid (glycol) which is piped to a mechanical room where heat exchangers and pumps distribute the energy for the building’s consumption and export into the district energy loop.

• Reduces fossil fuel inputs
• Improves air quality
• Lowers the carbon footprint of the district heating system
• Promotes the use of solar hot water in new commercial sectors
• Advances the environmental goals of the public and private sector

District Energy St. Paul is operated and managed by Ever-Green Energy.