On its websites www.sonnendach.ch and www.sonnenfassade.ch, the Swiss Federal Office of Energy SFOE shows which types of building surfaces are suitable for generating solar energy. This is the result: Switzerland’s roofs and facades have an annual solar power production potential of 67 terawatt-hours (TWh) (Press release SFOE 15.4.2019, in German, French, and Italian). This exceeds Switzerland’s current power consumption by over 10 percent!
An in-depth analysis including photovoltaics’ potential on roads, highway embankments and open alpine spaces can be found here: The Swiss PV potential based on individual buildings. Meteotest/Swissolar 2019 (PDF, in German)
Swissolar has analyzed the potentials according to building types and roof sizes. Conclusion: the greatest potential lies in small and medium-sized systems on multifamily houses, as well as industrial and commercial roofs. Additional incentives are urgently needed for situations where such systems cannot contribute significantly to self-consumption. Swissolar 2020 (PDF, in German)
Some of the available rooftop and facade surfaces can also be used for solar collectors to produce heat. In an earlier study (2017), Meteotest stated that this potential amounts to 11 TWh, which is about 10% of Switzerland’s current heating requirements. If the demand were reduced by implementing adequate isolation, solar thermal could even cover 20% of our needs.
The need for action on decarbonization is not sufficiently taken into account by the current version of the Energy Act (EnG): according to Art. 2 EnG, annual electricity production from renewable energies (excluding hydropower) should achieve at least 11.4 TWh by 2035. Calculations made by National Councillor Roger Nordmann have revealed that we need to install 50 GW of photovoltaic power until 2050, producing 45 TWh every year, in order to compensate the dismantled nuclear power and to cover the additional demand of electromobility and heat pumps. This is assuming that Switzerland’s power supply will remain independent of electricity imports in the annual balance. Our country has enough buildings to install this PV power without needing any additional surfaces.
Roger Nordmann's book «Sonne für den Klimaschutz» («Solar for climate protection») is available in French and in German and can be ordered via our webshop.
More realistic scenarios than the ones outlined in the perspectives 2013 can be found in the recently published Energy Perspectives 2050+ by the Swiss Federal Office of Energy. The «Zero Basis» scenario suggests 33.6 TWh of electricity to be provided by national PV installations by 2050. From Swissolar’s point of view, this value is clearly too low, and the proposed slow expansion is also associated with major risks in terms of security of supply.