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“Alpine solar plants are a small but important component of the energy transition in Switzerland”
23.07.2024 Four universities of applied sciences, including BFH, have launched alpine-pv.ch, a new platform that offers an overview of planned alpine solar plants. Since the solar offensive came into force in April 2023, a solar boom has broken out in the Alps. In an interview, Christof Bucher, Head of the Laboratory for Photovoltaic Systems at BFH, puts the hotly debated topic into context.
How many photovoltaic installations are currently being planned in the Swiss mountains?
We are currently aware of 27 projects that are being actively pursued and have a good chance of being realised. At an average output of 25 MW or so, at some point they will supply around 1 TWh of solar power per year, roughly 42% of which will be generated in winter. By comparison, the rooftop PV systems installed in 2023 alone produce 1.5 TWh of solar power per year, which is 50% more.
What are the objectives of the newly launched alpine-pv.ch platform?
Many planning teams currently have to plan and build alpine PV systems as quickly as possible in order to benefit from the one-off federal subsidy. There are still a lot of unresolved technical challenges. The teams are not in competition with each other, as all systems can be built. These are ideal conditions for collaboration and the exchange of knowledge. And that is precisely the goal of alpine-pv.ch: to make projects more efficient by sharing experiences and examining tricky issues together.
What is BFH’s contribution?
The Alpine-PV project is split into several work packages. Each university of applied sciences is in charge of a number of key topics. BFH acts as overall management, with responsibility for the technical structure of the platform, inverters and system-related issues. For instance, we are working on the question of the optimum inverter output for a given system. Due to the high irradiation peaks in the mountains, this question cannot be answered from our experience on the Central Plateau.
Are alpine PV systems the solution for the energy transition in Switzerland?
They are a small but vital component. Their numbers are low compared with rooftop PV systems, meaning that even during the winter half of the year, much more electricity is generated by rooftop systems due to their sheer volume than by the planned alpine systems in the same period. On foggy winter days, however, when the weather in the mountains is glorious, the alpine systems really come into their own and act as an ideal complement to the rooftop systems.
What would the ideal energy landscape in Switzerland look like for you?
I firmly believe that in the short and medium term, photovoltaics will become the second pillar of the electricity supply alongside hydropower. Electricity demand stands to increase by around 50% due to the electrification of transport and heating. Photovoltaics could well cover up to half of this.
What are your hopes for the future?
I would hope that the energy debate will be conducted in a technology-neutral, transparent and honest manner. By that I mean that the disposal of nuclear waste should be priced in precisely the same way as the risk that China might no longer supply us with PV modules. Here we need to realise that our dependence on foreign oil, gas and uranium is absolute. We are also utterly dependent on foreign countries for the construction of new photovoltaic systems, even if most of the added value remains local. But every PV module, once installed, will produce electricity reliably for 30 years, even if all supplies from abroad no longer reach us.
