HIGH-TEMPERATURE WATER PIT STORAGE PROJECTS FOR THE SEASONAL STORAGE OF SOLAR-ENERGY

Central solar heating plants with seasonal storage (CSHPSS) are capabl e of covering more than 75% of the annual heat demand of housing areas if appropriate storage technologies are available. The maximum design temperature should be 90-95 degrees C and the long term cost goal is 100 DM m(-3) for a storage volume larger than IO 000 m(3) water equiva lent. Three pilot projects are presently under construction and planni ng in Germany with 600, 4500 and 12 000 m(3) volume. The storage mediu m in all three cases is water. A first pilot heat storage with about 6 00 m(3) volume is being built in Rottweil. This small scale project wi ll be applied as short term storage in connection with a combined heat and power (CHP) plant. The storage container is made of concrete, wat er tightness is achieved by a stainless steel liner and mineral wool i s used as insulation. The aim of this project is to demonstrate the fe asibility of the technology and to gain practical experience for the c onstruction of larger stores. During 1995/96 two full scale central so lar heating plants with seasonal storage (CSHPSS) of this type will be built in Hamburg, North Germany and Friedrichshafen, South Germany, w ith 4500 and 12 000 m(3) storage volume, respectively. (C) 1997 Elsevi er Science Ltd.