Operational experiences of a solar cooling plant
"The synchronous occurrence of solar irradiation and cold demand and its causality led to the development of solar cooling facilities. Previously, a number of prototypes and demonstration plants have been erected world wide. Several techniques and concepts are discussed currently and there is still a high necessity for research and development. But there are also first operational experiences gathered by the existing plants. For the further development of solar cooling and the implementation of these systems into the market, it is important to evaluate and to interpret the available experiences. Since 2002 Fraunhofer UMSICHT has operated a solar cooling plant on its premises in Oberhausen, Germany. The plant target cold capacity is 58 kWth for space cooling. Most of the motive heat energy is provided by a solar tube collectors field while the backup heat source is the heating system of the institute. The plant also provides solar surplus heat to the institute heating system in spring and in autumn. Furthermore, the plant concept allows the operating mode "free cooling", which means that the cold capacity is exclusively provided by the recooling unit when the ambient air temperature is low enough. The proposed paper describes the solar cooling plant and its integration in an existing energy supply network. In addition, it summarises and analyses the operating experiences of the years 2002 to 2007."