Mercedes-Benz / Alpha Real – Winner of the First Solar Car Race

Two years before GM’s Sunraycer won in Australia, Switzerland held the world’s first race for solar vehicles. The Tour de Sol 1985 was meant to show that solar energy works not only in hot countries but also in the Swiss climate. 73 solar vehicles started in five stages from Romanshorn on Lake Constance via Winterthur to Geneva, on open roads and following all traffic rules. 58 made it to the finish.

The winner was a silver car built by Mercedes-Benz together with the Swiss engineering office Alpha Real of engineer Markus Real. The rules limited the solar generator to 480 Wp (or 6 m²) and the battery to 4.8 kWh. The car’s 480-watt solar array fed two small DC motors of about 1.2 hp each and charged a silver-zinc battery. Under the fibreglass body it had real car technology: independent suspension, rack-and-pinion steering and disc brakes.

Driver Peter Bauer won all five stages and covered the 368 km in 9 hours, 42 minutes and 13 seconds. On the last stage from Lausanne to Geneva he averaged about 60 km/h. The car is now part of the collection of the Mercedes-Benz Museum in Stuttgart.

The Tour de Sol ran every year until 1993 and grew to include solar boats, races on snow and human-powered classes. Its organisers note that the race helped give rise to the first Swiss electric bikes and motorcycles, and to the idea of feeding solar power into the grid. A small Swiss rally in 1985 is part of the story behind the solar bike adventures of today.

Technical data

Photos

• Top photo: Morio / Wikimedia Commons, CC BY-SA 3.0
• Seen from behind: the wide solar deck with lights and the Al… Photo: Morio / Wikimedia Commons, CC BY-SA 3.0
• From above: the solar array that powered the car to victory… Photo: Valder137 / Wikimedia Commons, CC BY 2.0

Sources

• Wikipedia (DE): Tour de Sol
• tzev.com: 1985 Mercedes-Benz Solar Silver Arrow
• enter.ch: Tour de Sol – Pioneer Era of Solar Vehicles