The solar pavilion stands like a Folie in front of a historic private house on Lake Walen. Under the light, 50m² roof, which is used to harness solar energy, there is space for two heat pumps and two electric cars. The use of solar energy to supplement the heat pump has long proven its worth. However, the pavilion also addresses the issue of energy buffering by enabling the activation of an integrated battery unit as well as the cars' batteries: on sunny winter days, the energy stored in the car batteries can be fed back into the heat pumps, reducing dependence on the power grid. Architecturally, the hybrid system construction follows a methodology that we are exploring in many projects in terms of its sustainable potential. A few custom-made solutions are combined with standard components, increasing their structural and spatial potential. The interplay between the simple and the special results in demountable constructions (design-for-disassembly principle) and an interesting, expressive formal language.