Accelerate Product Development for PV in Alpine Installations

Abstract

Numerous ambitious plans for infrastructure-integrated and large-scale alpine photovoltaic (PV) systems - especially in Switzerland - in the next few years show increasing interest in alpine PV systems. This requires the development of PV modules that can withstand the increased loads and extreme weather conditions of this harsh climate. High reliability and sustainability of these emerging systems must be guaranteed so that they can serve as models for electricity generation in the alpine and mountainous regions. Furthermore, PV integrated into buildings and infrastructure is important for the energy supply in the Alps. In addition, it must be taken into account that the fastening and substructure play a very important role in these applications and must therefore be considered during the development process. That´s why an innovative test strategy is now being developed as part of the Austrian-Swiss R&D project PVDetect to accelerate product development for Alpine PV. In addition to analyzing existing alpine facilities, this also includes the development of highly accelerated aging tests that simulate the stressors of alpine conditions as closely as possible. The occurrence of degradations and failures in these artificial aging tests is detected early on using sensitive characterization methods (electrical and material side). This enables a drastic reduction in the required testing time. Figure 1 shows the workflow of the project. Failures in the alpine environment are often associated with strong mechanical stress caused by snow, ice, or wind. Therefore, the focus of artificial aging tests is on combining this strong mechanical stress with low temperature, temperature cycles, and high irradiation. Initial tests on four-cell mini-modules show the formation of cell cracks and resulting electrical degradation through dynamic mechanical load tests after temperature cycles. Therefore, increased work is now being done to optimize the cell encapsulations. Comprehensive thermomechanical material tests are carried out on various encapsulation materials at temperatures between -40 and +50 °C to determine their stiffening at low temperatures. The next steps will be to optimize the module structure and develop the testing strategy.