Germany’s first ground-mounted PV plant has been prequalified for automatic frequency restoration reserve (aFRR) services.
The industry first, a collaboration between Enerparc subsidiary Sunnic Lighthouse, Entelios and transmission system operator 50Hertz, demonstrates the potential for PV systems to provide grid stability services alongside renewable energy generation.
Try Premium for just $1
- Full premium access for the first month at only $1
- Converts to an annual rate after 30 days unless cancelled
- Cancel anytime during the trial period
Premium Benefits
- Expert industry analysis and interviews
- Digital access to PV Tech Power journal
- Exclusive event discounts
Or get the full Premium subscription right away
Or continue reading this article for free
The 37.4MWp Enerparc facility in Schkölen began commercial participation in the aFRR market on 11 November, marking a key step forward in how solar assets can contribute to grid stability. The achievement demonstrates that variable renewable energy sources can provide essential system services traditionally dominated by conventional power plants.
The project’s significance lies in its bidirectional aFRR capability. During periods of high solar generation, the system can rapidly curtail output to address grid oversupply, reducing reliance on fossil fuel plants for negative control energy. Conversely, previously curtailed capacity can be rapidly restored during power shortfalls, providing positive aFRR services even during periods of negative electricity prices.
This flexibility addresses a critical challenge in renewable energy integration: transforming solar from a variable generation source into an active grid stability asset. The capability becomes increasingly valuable as Germany’s renewable penetration continues to expand.
Successful aFRR prequalification demanded sophisticated technological solutions. The partners implemented comprehensive measurement systems, advanced data management protocols, and AI-supported forecasting models to meet stringent regulatory and technical requirements. The forecasting accuracy and rapid response capabilities required for aFRR participation represent significant technological achievements for solar applications.
Entelios contributed flexibility service expertise developed across Germany’s energy markets, while Sunnic provided solar generation profiling knowledge gained from parent company ENERPARC’s extensive European portfolio operations.
Market implications
The successful prequalification establishes a transferable model for expanding solar participation in ancillary services markets. Additional Sunnic portfolio plants are expected to follow pending prequalification, potentially creating a new revenue stream for solar operators while enhancing grid stability services.
Arved von Harpe, managing director of Sunnic Lighthouse, highlighted the significance of the development for PV’s future ability to provide grid-stabilising services.
“The successful integration of our PV plant into the aFRR market is a paradigm shift – not only for Sunnic and our industry, but also for the entire energy system,” von Harpe said. “Together with Entelios, we were able to implement a forward-looking concept that shows that even volatile renewable generation plants such as photovoltaics are capable of helping to stabilise our power grid in the event of fluctuations.”
Fabian Becker, CEO of Entelios, added: “This project is a real milestone—and proof of what is possible when technological innovation meets partnership-based collaboration. For us at Entelios, it is a central goal to break new ground in flexibility marketing and to actively shape the energy transition together with strong partners.”
