Development of an approach to assess the investment decision in high-capacity batteries installed in plus-energy buildings

In recent years it became constantly more attractive for owners of plus-energy buildings to use a greater amount of electricity produced by their photovoltaic system for their own demand. One possibility to raise that share is the installation of high-capacity electricity storages. However, it is assumed that appropriate battery storage systems will be prevalent only in case of an economic advantageous purchase. As part of this paper the Excel tool SWA for an economic solar storage analysis has been developed. Taking into account all relevant parameters and their object-specific manifestations, the programme displays the output of the case-specific most economic storage capacity and associated economic indicators. The aim of this paper is to present the results of comprehensive analyses performed with the SWA tool. The essential finding is that an economic storage operation is currently not an option - but might be in the future, under certain identified circumstances.