At the Repowering of PV systems older photovoltaic systems are being upgraded with modern, more powerful components in order to increase the Yield and the Efficiency to increase. This can include measures such as replacing old modules with new, more efficient models, renewing inverters or optimizing the cabling and substructure. The aim is to improve the performance of the system, reduce downtimes and increase profitability in the long term.
When is repowering PV systems worthwhile?
Repowering is particularly worthwhile for photovoltaic systems that 20 to 25 years are old or whose components no longer work efficiently due to ageing, wear or defects. As a clear cost-benefit calculation is always individual, it is recommended that systems older than ten years are to repeatedly carry out new calculations. Particularly in the case of a long Remaining term of the feed-in tariff a renewal can make economic sense. Even with a Performance Ratio from only 70 to 75 % repowering should be considered, as this indicates a significant loss of efficiency. Another reason for modernization may be a planned roof renovation, which requires dismantling and reassessment of the solar system anyway.
Laut International Technology Roadmap for Photovoltaic (ITRPV) ist nämlich der durchschnittliche Modulwirkungsgrad im Zeitraum 2011 bis 2021 jährlich um etwa 0,56 % gestiegen. Setzt sich dieser Trend fort, könnten in den nächsten 10 bis 15 Jahren Wirkungsgrade von 26 bis 30 % für Standardmodule erreichbar sein. Demnach lassen sich durch einem Austausch älterer Module und Wechselrichter heute weitaus höhere PV-Erträge pro Quadratmeter erwirtschaften. Hier ein grober Überblick:
| Zeitraum | Ø Wirkungsgrad (%) | Leistung pro m² (Wp) |
| 2000 | 12-15 | 120-150 |
| 2010 | 15-18 | 150-180 |
| 2020 | 18-21 | 180-210 |
| 2024/2025 | 20-24 (Standrad) | 200-240 |
| 2025-2030 (Prognose) | 24-28 | 240-280 |
Advantages of repowering PV systems
Repowering solar systems offers numerous advantages. Through the use of modern, more powerful modules and Inverter energy production is significantly increased. While modules with a maximum of 350 W were standard around ten years ago, today's stand-alone modules achieve around 450 W. For even older systems, the differences are even greater. In recent years in particular, the Efficiency of solar cells developed enormously. The latest generation of inverters also works much more efficiently. In addition, the repowering of commercial PV systems usually involves the installation of a modern Energy management system integrated. This not only monitors the entire solar system, but can also control and optimize a company's entire energy consumption.
These technical improvements reduce also the Maintenance and operating costs through the Higher reliability of the new components. The result is a significant increase in the cost-effectiveness of the system and an extension of its service life. Another advantage lies in the increase in efficiency: higher yields can be achieved on the same surface area, or individual modules that are permanently shaded can be omitted without affecting the overall yield. This leads to higher savings, increased yields and a further increase in the value of the property. Repowering also makes an important contribution to climate protection. The more efficient generation of energy supports the expansion of renewable energies, conserves fossil fuels and reduces energy consumption. reduces CO₂ emissions. In this way, you not only benefit economically, but also contribute to the energy transition and a more sustainable future.
Legal framework
The repowering of photovoltaic systems was supported by the Solar package 1which has been in force since May 2024. With the aim of accelerating the expansion of solar energy, the 2023 amendment to the EEG provides for simplified approval procedures and financial incentives. The key points of the legal changes are
- Retention of the EEG remuneration claim when replacing modules: The previous EEG remuneration model remains in place, even if individual modules in the system are replaced. The prerequisite is that the new output remains within the originally registered capacity. The remuneration continues to be paid on a pro rata basis for the remaining term.
- Additional remuneration for extra work: If the total output of the system is increased through the use of new, more powerful modules, the additional output share is considered a new system. This is entitled to the current EEG remuneration for 20 years plus the year of commissioning. This makes repowering particularly attractive, as modern modules are often not only more efficient, but also more cost-effective.
- Elimination of proof of damage: Previously, it was necessary to prove a defect, damage or theft when replacing components in order to retain entitlement to the subsidy. This hurdle will be completely removed with the 2023 amendment to the EEG, which will make it much easier to renovate existing systems.
- Direct marketing and joint billing: The regulations on direct marketing have also been simplified for repowering projects. Even if additional output is treated as a new installation, joint billing is possible, which minimizes the administrative burden.
These legal innovations not only promote the economic incentive to modernize existing PV systems, but also support the long-term use of rooftop and ground-mounted systems in terms of the energy transition.
Increasing efficiency by repowering PV systems
Repowering PV systems offers an ideal opportunity to make older solar systems more efficient and economical. In addition to technical optimization through modern modules, inverters and energy management systems, the simplification of the legal framework through Solar Package 1 also makes a significant contribution to maximizing the potential of existing systems. The combination of higher yields, reduced operating costs and extended remuneration periods not only makes repowering financially attractive, but also makes an important contribution to climate protection and the energy transition. This makes repowering a forward-looking option that benefits both turbine operators and society.