District Energy systems provide thermal energy from a central plant in the form of steam, hot water, and/or chilled water through a network of pipes to meet the space conditioning or process heat needs of connected residential, commercial and industrial users. District steam can also run absorption chillers or turbine-driven centrifugal chillers in individual buildings. When electricity is cogenerated, District Energy systems squeeze more energy out of each unit of fuel consumed, and can raise the efficiency of power plants from about 30% to more than 90%.As a developed and reliable technology, District Energy can provide heat, cooling and electricity at prices that are often more competitive than conventional energy services, while offering other benefits, as well:
- Fuel Efficiency and Flexibility. Proven and reliable District Energy technologies can:
- Improve conversion efficiencies for conventional fuels
- Use a wide variety of relatively inexpensive alternative fuels
- Reduce the need for smaller, less efficient in-building boilers.
- Environmental Quality. State-of-the-art systems can improve air quality through:
- High conversion efficiencies that allow less fuel to be burned
- Better emissions controls than many individual building boilers
- The ability to provide cooling without the use of CFC's
- Electric Power Management. As much more than just a heat delivery mechanism, District Energy can:
- Operate with both alternative supply and demand management capabilities
- Support load management strategies that extend current generating plant capacity
- Augment the nation's pool of stable, decentralized electric power
- Customer Cost Savings. By eliminating the need for individual building boilers, District Energy:
- Reduces a building owner's capital, operating, and maintenance costs
- Increases revenue-producing space
- Improves the quality, efficiency and reliability of heating and cooling services
- Economic Development. District Energy can help revitalize declining urban cores by:
- Providing low-cost, long term energy as an attractive incentive for business location
- Keeping more energy dollars spent within the community
- Creating jobs for system construction or expansion
Despite the advantages of District Energy, operating systems currently supply less than five percent of the heating and cooling load in the United States - a penetration that is well below the full market potential for District Energy. Analyses by Argonne National Laboratory and the International District Energy Association (IDEA) estimate that District Energy could provide up to 30% of the nation's thermal energy needs by the end of the next decade. New and expanded markets include urban areas, universities and colleges, military installations, and other campus or institutional settings. There is a significant growth opportunity for the decade ahead.In contrast to the current U.S. situation, cogenerating district systems are used extensively in other industrialized countries. Denmark fills nearly 50 percent of its space conditioning requirements through district systems, and Sweden has positioned District Energy in the forefront of its national energy picture. Japan's aggressive approach to district systems has resulted in a four-fold growth over the last decade, and Great Britain recently singled out efficient cogeneration as its major strategy for reducing CO2 emissions to address the issue of global warming.