The solar-powered caravan Solar Butterfly has returned to Horw (canton of Lucerne) after a four-year journey around the world. The vehicle, equipped with extendable solar panels, covered approximately 100,000 kilometers across 47 countries on five continents. According to some sources, the panel area is 40 square meters; according to others, 80 square meters.
The project was developed by students of the Lucerne University of Applied Sciences and Arts and funded through donations and sponsorships. The caravan was also presented at a climate conference in Brazil in 2025.