Falling costs for battery storages increase the economic value of facade photovoltaic systems integrated into a building energy system in Europe

Photovoltaics (PV) is a key technology in the transformation of the energy system with a large share being installed on rooftops. In addition to rooftops, facade surfaces also offer a significant potential, but their widespread use is hampered by higher costs and lower annual yields. We model the energy system of a free-standing building and show that the inclusion of a battery storage results in a pronounced increase of the economic value of PV on south-facing facade surfaces. This is because the battery as a short-term storage and the seasonally favorable generation profile of facade PV complements each other.