Solar energy

Use of the sun’s energy through solar arrays on roofs or facades is increasingly common and has a definite role to play in a sustainable energy mix as the sun’s energy, so long as it is shining, is unlimited. As with wind energy, its inconsistent nature makes it hard to use as the sole energy source for a building, especially in areas with harsh winters where the majority of building energy is used for heating during a cloudy winter. In highly energy efficient buildings, however, a significant share of the remaining energy demand can be covered via the electricity produced by photovoltaic arrays. Additionally, more than a third of a Passive House's total energy consumption can be covered by hot water collectors - a substantial share when you consider that Passive Houses require more energy for the generation of hot water than they do for heating. Thermal collectors are a definitely the sustainable solution for the provision of hot water.

Casa EntreEncinas in Llanes, Spain, (top right), makes use of solar collectors for both hot water and heating while high efficiency combined with solar arrays makes the Belfied Homes social housing development (bottom right) “Net-Zero-Energy-Capable.” The Kranichstein Passive House, the world's very first Passive House located in Darmstadt, Germany (bottom left), uses solar vacuum tube collectors to cover about two thirds of its energy use for hot water. The 1954 Passive House retrofit in Wachtberg, Germany (top left) receives 75 percent of its energy needs via the photovoltaic array shown above.

All are Certified Passive House Buildings.

See database entry for Casa EntreEncinas
See database entry for Belfied homes  (Winner of Passive House Award 2014)
See database entry for the Wachtberg Retrofit
See database entry for the Kranichstein house | Read more on Passipedia