ABSTRACT

Large-scale solar heating technology is primarily intended for connection to district heating plants, DHW production for hospitals, local district heating plants for housing areas, or similar systems. There are two basic systems: one in which the solar heating system is designed to cover about 10% of the connected heating load (a short-term heat store) and one in which solar heating can cover up to 70% of the connected heat load (seasonal heat storage). In Sweden there are almost 1000 heating plants with yearly heating loads of 1–100 GWh for which solar heating can be a useful supplement. Solar heating plants with short-term storage can be an economic alternative to oil, particularly for local heating plants of between 7 and 32 GWh/year. According to a report published by NUTEK (the Swedish Business Development Agency) there are over 250 heating plants in Sweden with a total oil consumption of 2.7 TWh/year. Smaller local heating plants for housing areas where solar heating can be combined with biofuel via a short-term store are also of interest.