The Lake Wohlen was constructed in 1920 in order to build a hydropower plant.
Today, its operator BKW offers raft trips for groups on it.

To mark the site's 100t year anniversary, the energy supplier commissioned a redesign of the raft. The aim was to bring visitors closer to the historical background of the company and the weir.

To address the topic of power generation, a solar system was to be integrated onto the roof construction. The task was to find ways how to apply PV modules to the roof's coloured, translucent material while maintaining it’s visual and functional qualities.