1.7.2 District Energy Systems
Maximize efficiencies in energy generation, use and distribution: a district energy system takes steam, hot water, or chilled water from one or more sources and distributes that thermal energy to multiple customers through a network of buried, insulated pipes.
Three basic components: a source of thermal energy, a piping network to distribute that energy, and a mechanism for utilizing that energy in buildings.
The district energy from a combined heat and power plant offers even greater environmental benefits when the source energy is renewable or low-impact, as is the case with high-temperature geothermal, wood chips, or landfill gas.
Up to 60 percent of the energy content of fuels used for producing electricity is lost the moment the electricity is generated, expelled via cooling towers as waste heat. District energy systems that derive their heat from combined heat and power (CHP) plants—also known as cogeneration—significantly boost efficiency. These systems distribute heat directly to homes, offices and institutions. Cost: District energy systems are expensive with payback periods ranging from 20 to 40 years.