Before 2023, solar modules could only be replaced if they were defective, damaged or stolen and only with the same module output – otherwise, the operator would lose the EEG remuneration for the new modules.
This has changed since 2023. The recent update in section 38b of the Renewable Energy Act (EEG) allows modules to be replaced even if they are not defective, damaged or stolen. The goal is to encourage the use of existing areas with more efficient and powerful modules.
According to a calculation by the German Association of the New Energy Industry, this could potentially increase Germany’s solar expansion from the current 63 GW to 100 GW in a brief period.
In addition, by using new components, the warranty period and the operational lifetime of the park are extended. This may allow the park to continue operating beyond the EEG subsidy period or to be sold at a higher price.
There are three scenarios to consider: replacing the modules without increasing the total output of the park, replacing the modules and increasing the total output, and completely replacing all components and significantly increasing the output.
In this scenario, the old modules are replaced with more powerful modules, but the total output remains the same. Less space is required.
No new building permit is necessary. Only in exceptional cases does the operator have to apply for a change in the building permit if the number of photovoltaic modules is specified in the building permit.
The new modules are no longer considered a new installation under the law. With the same overall electricity production, they can still benefit from the previously higher EEG tariff. The new modules are given the commissioning date of the old modules and the right to the subsidy is automatically transferred to the new modules.
To boost the total output, the old modules are replaced with more powerful ones. However, unlike the first scenario, the entire surface area is now covered by new modules. The inverters typically do not need to be replaced, as many inverters can operate at a higher generating capacity.
An amendment to the permit may only be necessary if the permit specifies the number of modules or the maximum power to be attained.
However, not all of the output can be compensated at the old EEG tariff. The EEG tariff only applies up to the capacity previously installed. According to section 38b, subsection 2, sentence 3 EEG, the electricity fed into the grid is only eligible for payment based on the proportion of the originally installed capacity (compared to the new total capacity).
Any excess power not covered by the feed-in tariff must be sold in some other way. Section 21b of the Renewable Energy Sources Act requires a clear allocation to the respective forms of sale and a verifiable percentage breakdown of the different forms of sale at all times. If the electricity is sold directly via a power purchase agreement, the total feed-in must be measured and balanced every quarter of an hour.
In this scenario, all components are replaced – modules, inverters and substations. Due to the higher DC and AC output, the absolute yield of the solar park can in some cases be increased by 3.5 times.
A modification permit and a nature conservation assessment will likely be required. In addition, it may be necessary to adjust the plant certificate, extend the grid connection and redesign the cable route. The existing lease, insurance, and operation and maintenance contracts may require extension as well.
Large parks that usually require an environmental impact assessment as part of the modification permit may qualify for an exemption under European law. Until mid-2024, repowering measures that do not occupy a larger area than the original installation are exempt from a comprehensive environmental impact assessment. Moreover, the entire permitting process is limited to six months (Art. 5 of the EU Emergency Regulation 2022/2577).
Up to the previously installed capacity, entitlement to the feed-in tariff payment remains unchanged. Beyond that, the energy needs to be marketed in different forms, as in the second scenario.
If the old modules are still working, it may be worthwhile to sell them to individuals or companies. However, the vendor is in principle liable if the modules are faulty.
Limiting liability towards private buyers is difficult.
There is greater flexibility towards businesses. However, general exclusions of liability for various sales are subject to German laws on standard terms and conditions. Therefore, limitations of liability are only partially feasible (for example, reducing the limitation period to one year).
Alternatively, disposal of the outdated modules is an option. Under the Electrical and Electronic Equipment Act (ElektroG), manufacturers are generally responsible for collecting their old modules. They must provide reasonable return options and they must bear the costs of disposal (section 19 ElektroG). Nonetheless, the take-back obligation does not apply to modules put on the market before 24 October 2015.
With the assistance of our colleague Johanna Malavé Malavé