German households are increasingly using self-generated solar power.

Around 17 percent of the solar electricity generated is now used directly on site. This is shown by a new evaluation model developed by the Fraunhofer Institute for Solar Energy Systems ISE. We believe this trend is moving in the right direction, but there is still far greater potential to be unlocked.

For this analysis, researchers at the Fraunhofer Institute developed a method to quantify self-consumption. Installed photovoltaic systems were categorized according to commissioning date, capacity class, and system type. Based on this, they identified 44 different self-consumption groups, from which several key insights can be derived.

Reasons for the increase in self-consumption

The share of self-consumed solar electricity in German households is steadily rising, driven by both economic and technological factors. Two key developments in particular have shaped this trend: on the one hand, the framework conditions for feed-in and self-consumption have changed; on the other hand, new technologies enable more efficient on-site use of solar power.

Declining feed-in tariffs increase self-consumption

Until around 2009, the self-consumption of solar power was still uncommon. The reason was that feed-in tariffs were, on average, higher than the cost of purchasing electricity from the public grid—an apparent paradox. This price relationship has changed significantly over the years. Today, direct consumption of self-generated solar electricity is economically more attractive than feeding it into the grid. With feed-in tariffs now at just a few cents per kilowatt-hour, the gap continues to widen, as consumers pay increasingly more for grid electricity compared to the compensation received for their own PV power.

Sector coupling continues to gain importance

At the same time, so-called sector coupling—the intelligent linking of electricity, heat, and mobility—is becoming increasingly important. It enables more efficient use of self-generated solar power and thus makes a significant contribution to rising self-consumption.

The figures clearly illustrate this trend: while around 3.55 terawatt-hours of solar electricity were self-consumed in 2020, this figure increased to approximately 5.57 terawatt-hours by 2024. Key contributors include charging infrastructure for electric vehicles, battery storage systems, and domestic hot water and thermal storage solutions. Solutions for the solar-electric use of surplus power, such as for water heating, are also playing an increasingly important role. Systems like those from my-PV enable excess photovoltaic electricity to be converted directly into heat and used for domestic hot water or space heating support. In this way, self-consumption can be further increased while feed-in to the public grid is reduced—making it a win-win approach.

Significant increase in the share of self-consumption

Due to changing economic conditions, rising electricity prices, and the growing adoption of sector-coupling technologies, self-consumption has increased significantly in recent years. The share of solar electricity used on site rose from 13 percent in 2023 to 17 percent in 2024. When comparing these self-consumption rates with those of our reference projects, it becomes clear how much untapped potential still exists.

No grid expansion required for rooftop PV systems

Looking at another finding from a study by HTW Berlin, which shows that the expansion of rooftop PV systems does not require additional grid upgrades, it becomes even clearer that increasing self-consumption of one’s own PV power makes sense. Only in this way can households consume enough of their self-generated solar electricity without unnecessarily burdening the public power grid. The study concludes that PV expansion does not cause any additional grid reinforcement beyond what is already required for electrical consumers. All details can be found in this study report.