Solar power station for home in Germany

To date, most battery storage systems in the German electricity system have been used exclusively to optimize self-consumption. Consequently, an exponentially growing number of homeowners and companies store solar power for times when solar generation is low.

Household photovoltaic systems are a mainstay in achieving the German Federal Government's declared objective of significantly expanding photovoltaics. So far, only a small percentage of Germany's roof surfaces is equipped with photovoltaics. Recently, however, a significant increase in the installation of such systems has been observed.

Sustained growth is forecasted in the market for new PV capacity for years to come. Concurrently, battery systems are expected to reach a capacity of at least 100 GWh by 2030, reflecting a transformative shift within the German energy system towards renewable energy integration.

Household rooftop photovoltaics, which accounted for more than half of all systems installed in Germany in 2023, play an important role here. But not all regions in Germany are equally suitable for their installation. The purpose of this study is to identify regions which still have a particularly high potential for new installations.

In 2019, 46% of all commissioned residential rooftop PV systems had already been paired with battery storage systems. Remarkably, this share surged to 77% in 2023, indicating a significant upward trajectory of the trend toward combining PV residential rooftop systems with battery storage in Germany.

Most installations are located in the south of Germany, where some regions already boast one in five dwellings with photovoltaics. Global radiation as a measure of incident solar energy determines how much electricity a photovoltaic system can generate.