Tanks with high storage capacity and reduced losses are key to an increased solar heat share in households. Austrian research institute AEE INTEC has recently inaugurated a pilot research facility which promises exactly that: greater storage capacity than water and almost zero energy losses even in seasonal mode. The heart of the test facility are two low-pressure vessels filled with 750 kg of zeolite beads or spheres each. “Our first measurements since the beginning of October were very promising,” confirms Wim van Helden, head of the research project at AEE INTEC. “We reached a storage density of 180 kWh/m³, which has never been achieved before in a device of this size.” The research is part of an EU-funded project called COMTES – Combined Development of Compact Thermal Energy Storage Technologies and was co-financed by the Austrian Climate and Energy Fund. Theresia Vogel (second from left), Managing Director of said fund, joined the official starting ceremony on 11 November 2015.