On match days, a sea of football fans travel along the FR1 and descend on the 24,000-seat Schwarzwald-Stadion, Germany’s first solar-powered football stadium that’s home to local heroes SC Freiburg. Since solar panels were fitted to the grandstand roofs in 1993, the stadium has generated 250,000 kilowatt-hours per year, powering the stadium and feeding any excess back into the local grid. Borrowing this design ethos is the much-anticipated new Freiburg Stadium, which is integrating solar panels onto its roof and recycling energy generated from a nearby manufacturing plant to heat the stadium. Boasting 10,000 additional seats, it’s on track to host its first match by the end of 2020.