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Case Study

Revamping your solar PV plant

Setting the scene

Photovoltaic (PV) assets need to be in peak condition to harness the sun’s power efficiently. Aged and outdated systems risk technical and operational issues, which could turn into business downtime and financial losses. This is where revamping comes into play: the replacement of defective or underperforming components such as inverters and/or PV modules with modern components, whilst keeping the original Total Installed Capacity (TIC). However, waiting too long to revamp your solar plant could lead to precarious situations, as several module and inverter companies have already quit the market entirely. 

These thoughts were on the minds of Sonnedix, the owners of the Saint Martin Lalande solar plant in the Aude department in southern France. It was commissioned in 2011, featuring 60,000 PV amorphous-silicon thin-film modules. The TIC of the plant was 5.4 MWp – but with modules already older than ten years suffering from premature degradation, the possibility of failure rates started to become a distinct risk. Furthermore, new technology was available that could make the plant more efficient. Something had to be done, and Sonnedix tasked BayWa r.e. with finding and implementing the optimal revamping solution for their solar plant.

The challenge

First and foremost, our colleagues had to make sure that the plant would still be able to provide output at least partially during the revamping process. This would also mean that they had to work quickly so that the plant could return to its normal output as soon as possible – time was of the essence.

Working on a live site also brought its own set of challenges with it. Our team in France had to carefully consider how to manage necessary equipment and material logistics on top of the plant’s day-to-day traffic. They also needed to constantly keep the workforce and local authorities in the loop about the project. It was clear from the outset that disruption had to be mitigated as much possible. To do this, accurate planning and proper communication would be key.

Finally, there was the question of what to do with the old modules that needed to be disposed of. This would require responsible end-of-life management: a robust yet sustainable disposal process to recycle as much material as possible. Our team had their workload cut out for them.

The result

Accurate site assessment and engineering were carried out and proposal was made to replace the old PV modules, maintain, and adjust the support structures where needed to support the new modules and keep the existing central inverters designing the new PV array to that electrical characteristics would match. Two important factors had yet to be considered: because of the higher efficiency of the new modules, less land would be necessary to host the plant, and at the same time a 10% increase of the TIC was authorized by the authorities. A plant layout that would incorporate the above while optimizing the use of the land was hence engineered.   

In less than six months, our French colleagues replaced 60,000 old thin-film modules with 18,000 new crystalline ones with a much higher efficiency. This happened in several stages, as to always keep the plant operational at least 65% of its usual output. To ensure that the new plant keeps working properly, BayWa r.e. will carry out regular maintenance in the future, supported by drone inspections for high accuracy and consistency.

The old panels, which weighed a total of 1,000 tonnes, were disposed of by PV Cycle, an approved eco-organisation for collection and recycling. Old modules were sent to Envie 2E, a company that specialises in the collection and processing of electrical and electronic waste. Envie 2E separated the aluminium frames from the modules so that PV Cycle could then recycle the unframed modules.

As a result of the sole revamping with new modules the plant is much more efficient than before: based on a one-year measured operation, the average performance ratio (PR) of the plant has increased by 37.1%, while its energy yield improved by 38.1%. The original FIT was maintained, financing the process. Further, since the new modules are more efficient, almost half of the land was freed-up which will be used for a repowering allowing an additional 4MW PV plant to be installed next to the initial. Once completed, the same land area that was initially hosting 5.4MWp will hold a TIC close to 10MWp dramatically improving the plant’s sustainability.

Our French team proved that with the right partner, revamping is less disruptive than commonly thought and ultimately a well-placed investment to not only future proof solar plants, but also to increase their efficiency.

As more and more aging PV assets struggle with low performance ratio, high maintenance costs, and potential health and safety risks, repowering plays an essential role in solar plant maintenance. BayWa r.e. has shown the experience and know-how needed to deliver repowering projects.

Adam Loucks
Vice President, Sonnedix

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