Long-term storage systems

Seasonal storage tanks, which for example are to cover the heat supply of a housing estate and are fed by solar thermal systems, must be dimensioned according to other system-specific criteria. The individual consumers are connected to these storage tanks via the local heating network (underground insulated pipes).

Underground energy storage is also possible. One example is geothermal probe heat storage systems, which tap the surface soil or rock layers at depths of 20 to 100 metres as a storage medium. (Lenz et al. 2010)

Another promising way for long term-storage is the so-called “Bauteilaktivierung” (activation of building parts), e.g. an insulated concrete basement or the insulated earth under the house is heated up during summer and gives back the thermal energy in the colder times. One example by TB Käferhaus GmbH can be seen here (PDF, German): http://www.kaeferhaus.at/images/veroeffentlichungen/02_13_bauteilaktivierung_wohnbau