Confederates fight against power outage. The Federal Council and Parliament are working hard to expand the energy supply. As a member of the Electricity Commission (Elcom), Felix Vontobel (64) is also dealing with the upcoming winter power outage – but as a private person he won’t be affected by it: his family’s house in PoschiavoGR produces more solar energy than his needs – for twelve months of the year.
The surplus energy building was completed in 2021. “We wanted to build in a solar, energy and resource efficient way,” Vontobel says. The house has complete insulation, heat pump, hot water tank and photovoltaic systems integrated into the entire surface on the facades and roof. With a production of 45,000 kilowatt-hours, it consumes only 7,400 kilowatt-hours of electricity per year. Thus, the building meets 609 percent of its own consumption.
“Big electricity surpluses even in winter”
The consistency of energy production will make you sit down and pay attention: The house also generates a large surplus of electricity in the winter – almost 400 percent of total consumption. This is unique in Europe. “Over the past year, the building has produced less energy than we used in just twelve days,” Vontobel says. “This gap can be closed with a simple battery.”
435 modules cover the entire building. But if you want to get to know them that way, you need to approach. “The aim was to combine technology and aesthetics,” says architect Nadia Vontobel (34). The client’s daughter consciously paid attention to the winter power supply during the planning: building orientation, roof slope, windows and cutouts were designed to receive as much sun as possible, even in the cold season.
A profitable option not only in mountain valleys
Such achievements are not only possible in sun-kissed mountain valleys. This is illustrated by an example of an apartment built in Fahrwangen AG in 1974. An energetic renovation reduced the total energy requirement from 137,000 kilowatt hours per year to 24,700 kilowatt hours. Solar energy systems located on the roof, facade and balcony railings provide 78,000 kilowatt hours of electricity per year. This is 315 percent of our own needs.
The building also generates large surpluses, 157 percent of total consumption during the winter months. Only 14 days a year exceed production, as energy consumption drops by 80 percent in the coldest months from November to January.
“The house in Fahrwangen is an impressive example of what is technically possible today,” says Stephan Attiger (55), Energy Director of Aargau. It is currently making a new attempt to revise the canton’s energy law. The first attempt at the ballot box in 2020 failed. Now the people of Aargau should continue to be allowed to install fossil replacement heating systems, and rooftop photovoltaics also continue to be voluntary. “We have to reduce consumption first, so a financing program with energy efficiency measures is important,” Attiger says. “There’s no point in removing an oil heater and then heating it outside.”
great potential
The energy house in Fahrwangen does both at the same time: it insulates and provides renewable energy. Architect Giuseppe Fent (70) carried out the renovation. He has been building solar houses for 30 years. “I don’t want to waste my time with pollution,” Fent says. Plus-energy buildings are also an economic benefit: “Investors spend nine percent more, but earn 26 percent more by selling the excess energy.”
The houses in Poschiavo and Fahrwangen were awarded this week by the Swiss Solar Energy Agency. They’re still pretty lonely. There are only 230 plus energy buildings in Switzerland. If half of the local buildings were built or renovated according to this concept, these homes could provide 127 terawatt hours of solar energy per year – double the current total consumption.