At first glance, one would hardly believe that a simple water tank could be enough to bring heat from summer into winter. But in fact, a storage tank with a volume of 12 cubic meters or more is enough to supply an apartment with heat and hot water from solar collectors for the entire winter. Because such storage solutions have been relatively expensive up to now, scientists from the universities in Rapperswil and Lucerne have been searching for ways to make the technology more economical in two research projects. Weiterlesen