Energy Labeling and Advanced Insulation for Thermal Energy Storages in Solar Applications

In order to reduce CO2 emissions related to heating purposes within the European Union, the EU-Commission is currently preparing ecodesign and energy-labeling requirements for water heaters, storage tanks, and space and combination heaters. Especially this also applies for solar assisted space heating and hot water preparation systems. In particular, there will be a new energy efficiency classification for solar hot water storage tanks, which will be rated (A+, A, B, C, ..., G) according to their standing losses. We present a test set-up and procedure that is capable of determining the standing losses conform to the EU-directive and show various measurements of some state-of-the-art storage configurations. The results reveal the need for better insulation in order to achieve an A+/A-rating for stateof- the-art storage tanks. We compare the effects of employing an better insulated storage tank compared to state-ofthe- art technology for a solar thermal systems by performing annual system simulations via TRNSYS. The system comprises of a 100% renewable space heating and domestic hot water pellet-solar combi-system suitable for residential buildings.