European collaboration on development of solar heating storages for combined heating and power systems

A report was completed in summer 2007. The report was successfully presented at the PREHEAT seminar, which took place at the Intersolar exhibition in Freiburg, June 21-22 2007. A PowerPoint presentation was elaborated. At the seminar were around 60 participants from European countries. The presentation resulted in several contacts to European companies interested in the subject. The report gives information on the work carried out and the results obtained in Denmark on storages for large solar heating plants in district heating networks. Especially in Denmark the share of district heating has increased to a large percentage. In 1981 around 33% of all dwellings in DK were connected to a district heating network, while the percentage in 2006 was about 60% (in total 1.5 mio. dwellings). In the report storage types for short term storage and long term storages are described. Short term, storages are done as steel tanks and is well established technology widely used in district heating networks. Long term storages are experimental and used in connection with solar heating. A number of solar heating plants have been established with either short term or long term storages showing economy competitive with normal energy sources. Since, in the majority of the Danish district heating networks the heat is produced in co-generation plants, i.e. plants producing both electricity and heat for network, special attention has been put on the use of solar energy in combination with co-generation. Part of this report describes that in the liberalized electricity market central solar heating plants can also be advantageous in combination with co-generation plants. The report gives information on the companies involved in the development. A detailed list of literature (mostly in Danish) and a list of projects carried out is given as a separate annex to the final report. The report and its annex are downloadable at www.elle-kilde.dk and will also be available from the Preheat website www.preheat.org. The report is presented at meetings in countries participating in the Preheat project and is used in the further Preheat work.