Solar Thermal Energy Storage for the Typical European Dwelling; Available Resources, Storage Requirements and Demand
Abstract
Thermochemical energy storage materials store heat at higher energy storage densities via reversible endothermic chemical reactions at ambient temperatures with lower thermal losses than sensible or latent energy storage systems. This research undertaken as part of the MERITS project, provides an estimation of the main requirements for domestic thermal energy storage from solar thermal collectors to meet thermal energy requirements (heating, cooling and hot water) for the mean European domestic dwelling (Floor area 98m2) built to the regulations specified in 1999, 2012 and 2020, assuming that thermochemical energy storage systems could be effectively developed for seasonal storage of solar energy with a round trip efficiency of 75% from laboratory test results reported in the literature. The thermal energy demands of the mean European dwelling was calculated for three different climatic zones across Europe; Atlantic (Belfast UK), Continental (Berlin, DE) and Mediterranean (Murcia, ES) using the Meteonorm data set for a Typical Metrological Year (TMY). Solar collector performance was derived from proprietary designs of vacuum tube collectors assuming a mean system efficiency of 50%. It was estimated that currently only in Spain can a seasonal thermal energy store meet all the thermal energy demands of a dwelling (heating, cooling and hot water). However with a super insulated dwelling, using standards close to that of a Passivhaus (<15kWhm- 2yr-1) thermal energy loads can be met with a reasonable area of solar thermal collector and storage volume for Atlantic and Continental climates.