District heating in greater Stockholm

The Stockholm municipality and the Swedish State Power Board have entered into a collaboration on a nuclear combined district heating power station (NHPS) in Greater Stockholm. These municipalities and the state have jointly studied the future heat supply for Greater Stockholm and, in particular, the alternative based on heat from an NHPS. The investigations embrace an NHPS located in Greater Stockholm or at the Forsmark nuclear plant (future units 3, 4, and/or 5) and various alternatives in which Greater Stockholm is supplied with heat by expansion of oil-fired plants. Different technical solutions were taken into account--type of turbine, method of transporting hot water, various outgoing temperatures, etc.--and the alternatives have been evaluated on different assumptions regarding fuel prices, investment costs, energy forecasts, and continued nuclear power expansion. The investigations show that district heating and combined district heating power stations will expand in the region. If the relation of costs between nuclear and oil power continues, the investigations indicate lower total annual costs of oil-based systems than systems based on an NHPS. This conclusion is valid even if the oil price should increase approximately 50%, provided that the number of nuclear power units is independent of whether or not they are used for district heating. But if the heat extracted from the station implies that the number of nuclear power units may be increased, the best nuclear alternative will be more economical than the best oil-fired alternative