Fresh impetus for photovoltaic research on Mont-Soleil

The solar power plant – standing at an altitude of 1270 m on Mont-Soleil in the Bernese Jura – has been in operation for over 30 years. There are very few large plants of this age in the world. The plant’s main aim is to conduct research on and demonstrate the potential of photovoltaics for contributing to the energy supply system. BFH’s Laboratory for Photovoltaic Systems – a scientific partner in the project – measures and evaluates the operational parameters of the plant whose degradation has been very low to date, at 0.13 percent per year. This means it has far exceeded all expectations in terms of lifespan and energy output. Despite some minor defects and visual signs of ageing on the PV modules, there is nothing to indicate the plant will need to be urgently decommissioned any time soon. But at the same time, it clearly cannot continue to operate forever either. As part of a pilot project, a concept is now being tested where the most relevant PV modules from Switzerland, Europe and worldwide will in future be periodically operated, scientifically analysed and compared on a benchmark plant, the only one of its kind in the world. Defective PV modules on the 30-year-old plant will be gradually replaced by new ones, doubling the facility’s efficiency and energy output. The research team from BFH’s Laboratory for Photovoltaic Systems will be mainly responsible for the scientific evaluation of the project and the publication of its data. The project partners are the Société Mont-Soleil, BFH and the Espace découverte Énergie Saint-Imier.

Testing various module types

By the end of May 2023, the pilot project aims to install a total of 40 modules with an output of around 15 kW and to connect them to measurement technology so that the data can be recorded and evaluated. Five different types of module from three different parts of the world (Switzerland/EU, USA, Asia) and incorporating four different technologies (PERC, IBC, HJT, TOPcon) will be installed. The long-term goal is to gradually replace the ageing PV modules on Mont-Soleil with much more high-performance and globally relevant new ones over the coming years and decades. The researchers can then test them using internationally recognised methods and compare them in long-term operation with the long-term data of the Mont-Soleil plant, which has been recorded since 1992.

Setting international PV standards

The project is seeking to significantly increase production of the solar power plant on Mont-Soleil long-term and to provide attractive innovation impetus for the market and for the industry and state funding of top-quality, high-performance and long-life PV modules. Mont-Soleil aims to set internationally recognised PV standards for quality and transparency and to become a magnet for visitors from Switzerland and abroad.