"Potential for Combined Heat and Power and District Heating and Cooling from Waste- to-Energy Facilities in the U.S. - Learning from the Danish Experience"

Executive Summary In District Heating (DH), a large number of buildings are heated from a central source by conveying steam or hot water through a network of insulated pipes. Waste-to-Energy (WTE) signifies the controlled combustion of municipal solid wastes (MSW) to generate electrical and thermal energy in a power plant. Both technologies have been developed simultaneously and are used widely in Europe. In the United States, however, WTE is used for the generation of electricity. The advantages of district heating using WTE plants are: overall fuel conservation, by increasing the thermal efficiency of WTE, and overall reduction of carbon dioxide emissions to the atmosphere. District heating in the United States is mainly based on the use of steam, such as the Con Edison Steam DH system in New York City and the Citizens Thermal Energy district heating and cooling system in Indianapolis. However, there are few U.S. hot water district heating systems presently, such as: Coop City in Bronx, NY, and St. Paul, MN. The United States has an estimated 5,800 district heating and cooling systems, providing 320 million MWh of thermal energy. Currently, 28 of the 88 U.S. WTE plants sell steam as an energy product. Twenty one of these WTEs co-generate approximately 470 MW of heat (1.6 million lbs of steam per hour) and 272 MW of electricity. Also, there are seven WTE plants that generate 273 MW of heat (929,000 lbs of steam per hour) exclusively. Hot water district heating systems are used widespread in Europe and gaining in popularity in the U.S. because of: cogeneration of heat and power at the power plant is achieved with a higher thermal efficiency, hot water allows the transmission of heat over long distances, with relatively low heat loss, less than 10%, the central control system for the heat supply from the power plant is more economic, the interconnection of the space heating and hot water customers to the district network is simplified, less corrosion problems, and the hot water network may provide heat storage capacity. Scandinavian countries have been very successful in promoting and increasing their hot water district heating networks. For example, Danish district heating supplies 60% of the heated floor, and 75% of the heat generation is generated in Combined Heat and Power (CHP) or cogeneration plants. In addition, European Parliament established the promotion of cogeneration based on useful heat demand in the internal energy market to …