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A project in the fields of Architecture, Mobility:

Solar Raft

Sustainable design on water

Designed as movable shading and energy systems

The Wohlenfloß on Lake Wohlensee near Bern represents a new dimension of sustainable design on water. Developed for BKW in collaboration with BELLPRAT PARTNER AG and Hafis Hermann Issa, it combines architectural clarity, technical innovation and the spirit of renewable energy.

At the heart of the concept are the radially opening OPV elements, designed as movable shading and energy systems. ASCA provided the full technical and structural solution – including the integration of organic photovoltaic modules into polycarbonate, as well as the folding and opening mechanisms for the roof structure.

The organic solar modules power the boat’s lighting, charging ports and onboard electronics, entirely independent of external energy sources. The system can be folded or dismantled during winter, complying with Swiss navigation regulations.

Constructed from steel, aluminium and lightweight polycarbonate modules, the Wohlenfloß merges engineering and elegance into a coherent architectural vision. It is a mobile manifestation of sustainable energy architecture – adaptable, functional, and in harmony with its natural environment.

Project Partners

  • Client: BKW AG
  • Design: BELLPRAT PARTNER AG, Co-Design: Hafis Hermann Issa
  • Construction: BELLPRAT PARTNER AG, ASCA
  • OPV Integration & Technical Implementation: ASCA GmbH & Co. KG
  • Assembly & Installation: ASCA
  • Steel construction: Andreas Rohrer AG