In Switzerland, at a height of 1,200 meters, the Markert family, together with the German eco-pioneer Baufritz, built a passive house which is completely independent of the public power supply. After two years of testing, it is clear that the turn to 100 percent renewable energies is possible.
I have used different, complementary systems so that the supply can work all year round, explains Hausherr Stefan Markert, project manager for renewable energies at Soltop AG (www.soltop.ch), his sophisticated concept. In addition, the project was honored for its great commitment to climate protection within the framework of the Swiss Climate Prize.
The solar thermal collectors are integrated into the house facade to generate hot water and support heating. A photovoltaic system with a rated output of 3 kWp placed in the garden in a south-facing position generates electricity for the 150 square meter detached house. The conditions are ideal: the clear mountain air, hardly fog, over 300 sunny days a year and the reflection of the sun rays through the snow in the winter guarantee high yields.
The solar energy supply is as high as in the Spanish Catalonia, says Stefan Markert. He built an additional PV plant with 1 kWp in the façade under the balcony. A small-wind power plant on the roof provides electricity if the photovoltaic elements are snowed in winter—and this is often possible in the Swiss mountains. The weekly supply stores a battery block in the cellar. A sophisticated control, almost a miniature power station, charges and discharges it. The energy supply is minimized by controlled ventilation with heat recovery.