Not just for smartphones, but for photovoltaic modules too: The RENEW project marks the launch of research into the repair and reuse of photovoltaic (PV) modules by Germany’s Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) and its partners. The three-year project is being funded by Germany’s Federal Ministry for Economic Affairs and Climate Action (BMWK). Its goal is more effective testing with high throughput of used PV modules and to develop new repair options in order to reduce the amount of discarded PV modules. The project partners are defin-ing new standards for characterising used PV modules, thus opening up a high utilisation potential. Alongside the ZSW, the companies involved are 2nd Life Solar, HaWe Engineering and ELMED Dr. Ing. Mense.
RENEW is the German acronym for the repair (“Reparatur”) and reuse (“Wiederverwendung”) of PV modules. A glimpse into the future reveals that global PV expansion targets will not only require a constant supply of new modules, but also that these be kept in operation for as long as possible, thus increasing sustainability and reducing PV electricity costs.
Thanks to the rapid technological development of module technology in the last decade alone, new modules are attractive to power plant opera-tors for economic reasons due to their higher output over the same sur-face area. Socalled repowering involves dismantling old modules and replacing them with new, more powerful modules, even though these may still be operational. Extensive experience with field-aged modules at ZSW’s Solab solar laboratory reveals that even after more than two decades of operation, the majority of modules exhibit almost no perfor-mance degradation, particularly at sites with a temperate climate as found in Central Europe. According to the experience of project partner 2nd Life Solar, around 70 percent of all discarded modules remain di-rectly operational. In order to improve these numbers even more, the project is assessing a variety of additional repair solutions as well.
Moreover, according to the waste recycling industry company, 2nd Life Solar GmbH, the amount of old modules that are currently being properly discarded does not correspond to their anticipated amounts, thus raising the question of where these modules will eventually end up as unchecked electrical waste. This is why their research team is placing its focus on the circular economy model. Before a module is recycled, its functionality is checked before it is then reused directly.
The longevity of PV modules, as well as their repair and test capacity after years of use, are the building blocks for future use. Because many manufacturers will no longer available to customers at the end of a module’s service life, the project recognises the great need across the nation for improving Germany’s repair and reuse capacities.
The demand for used modules is high
Maximilian Engel, project coordinator of the RENEW project at ZSW, sums it up: “The market for used modules is rapidly expanding because of the ambitious expansion targets for photovoltaics. We therefore need every module – whether new or used – to remain in operation until the end of its service life. Even if I’m happy about the current high rate of expansion, we mustn’t neglect the need for sustainable resource use. We therefore need to qualify used modules efficiently and thus cost-effectively with a high throughput, and repair these if need be in order to keep them operational”. Not only can they be used in smaller, stand-alone systems and as balcony power plants, it is also possible to equip entire PV parks with used modules thanks to the high quantity of avail-able field-aged modules.
Nationwide scaling planned
One project partner that is already conducting quality checks on used photovoltaic modules and reselling field-aged modules after extensive testing is 2nd Life Solar. The company intends to further expand its concept in order to meet growing demand. Such scaling requires robust process standards for mobile and stationary quality tests. By upscaling the processes, the project partners hope to reduce the amount of un-tested electrical waste transported abroad.
In order to optimise tests, the project team is teaming up with ELMED Dr. Ing. ELMED specialises in testing equipment from the coating indus-try and can therefore conduct tests with minimal material stress on the coating. HaWe Engineering GmbH will apply the project results in various PV systems in a field study in order to facilitate qualification of used modules on site.
Basis is a list of criteria for older PV installations
Project coordinator of RENEW is the ZSW. Its Solab solar laboratory boasts extensive experience with field-aged modules. The tests carried out at ZSW involve the degradation of PV modules, backsheet analysis and material analysis. The project team also draws on the results of a preceding project: analyses of damaged backsheets at the end of the project culminated in a comprehensive list of criteria for evaluating module defects. RENEW will enable the ZSW to enhance the quality of testing old modules and make it scalable – and thus make PV module use even more sustainable.
