It will be everywhere – so we better make it look good!

Photovoltaics is becoming an integral part of buildings and architecture. At the chair of Architecture and Building Systems, students learn how to integrate this technology as a new design element. There is no limit to creativity!


The Sun – what a blessing! Every second, this star radiates roughly 3.846 x 10^26 Joules of energy out into our solar system. To put that into perspective, the global population uses roughly 160 000 TWh of energy per year. In other words, the sun produces roughly 100000000 times more energy every second than the world population uses every year!


Even though we won’t by any means be able to capture every photon, i.e. every packet of energy, that arrives from the Sun here on Earth, solar energy does have a lot of potential for Switzerland. For example, if we covered 70% of Swiss rooftops with PV, we could generate 53 TWh of energy! (according to the national “Sonnendach” project, see Figure, left-hand side). For comparison, the current net electricity demand of Switzerland totals around 60TWh per year (SFOE 2022b) and is projected to increase to around 80-100 TWh in 2050.


But let’s not forget the social side: If you’ve considered PV for your own rooftop, you’re probably aware of the high upfront costs, the landlord-tenant dilemma as well as complicated permit regulations that can be difficult to navigate as an individual.



So what else can we do? Actually, there is another area with huge potential for PV in Switzerland: the mountains! Building alpine PV could provide additional 45-300 TWh of energy! 55% of that energy would even be produced in winter, which could help to address energy shortages in those months.


However, the recent referendum on alpine PV in the canton of Valais showed that Swiss citizens are concerned about how this energy technology would affect the plants and animals with whom we share these beautiful mountainous areas. Hence, ETH researchers are studying how to best combine alpine energy innovation with biodiversity protection, as part of the SPEED2ZERO initiative.


Until then, let us return briefly to PV in the towns and cities of Switzerland. Can we unlock potential here by being more creative? That’s exactly the mindset behind the workshop on Building Integrated PV (BIVP) that has been held yearly at ETH Zurich since 2021. In this workshop, students are encouraged to push the boundaries of traditional architecture and building aesthetics: They creatively use solar cells of different shapes and sizes as well as flexible thin film PV as a building material in its own right! Want to see this in action?


Our videos from last year (on the right side) provide a quick overview of the topic.

Since PV is going to be everywhere, it better look beautiful... Don’t you agree?