Solartaxi – The First Trip Around the World by Solar Car

The blue-and-white Solartaxi three-wheeler parked in front of a building at MIT

Some people dream of driving around the world. Louis Palmer, a Swiss schoolteacher from Lucerne, dreamed of doing it without a drop of fuel. In 2004 he challenged students at several Swiss universities to build a vehicle that could do exactly that. The result was the Solartaxi, and between 4 July 2007 and 18 December 2008 it became the first solar vehicle to circle the globe.

The car itself is a two-seat electric three-wheeler weighing about 500 kg, with a top speed of 90 km/h and a consumption of only 8 kWh per 100 km. A clever detail: the steering wheel can be moved, so either seat can be the driver’s seat. The energy came from a separate 250 kg trailer covered with about 6 m² of silicon solar cells, the same idea many of our members use today with a solar bike trailer.

The Solartaxi with its solar trailer: the panels rode behind the car, not on it. Photo: SayCheeeeeese / Wikimedia Commons, Public domain

The route ran east from Lucerne through Eastern Europe, the Balkans, the Middle East and India to Bali, where Palmer joined the UN climate conference 2007. Greenpeace’s Rainbow Warrior carried the car to New Zealand. From there the Solartaxi drove through Australia, East Asia, China, South Korea, Canada and the USA. Over 18 months it covered 54,000 km in 38 countries, with many people taking a ride along the way.

The Solartaxi visiting the MIT solar car team, next to its race cars. Photo: SayCheeeeeese / Wikimedia Commons, Public domain

Palmer was honest about the limits: on long days the car needed more energy than the trailer could deliver, so it was also charged from the grid. To balance this, the team fed the same amount of solar power into the grid from a solar installation in Switzerland. Engineer Thomas Gottschalk, who led the construction, was the only team member to ride along for the whole trip, and filmmaker Erik Schmitt documented the journey from India onwards.

On the road in Vermont during the North American leg of the world tour. Photo: SayCheeeeeese / Wikimedia Commons, Public domain

For the trip Palmer received the European Solar Prize (2009) and the UN Champions of the Earth award (2011). He went on to organise the Zero Emissions Race and the WAVE electric vehicle rallies. Fifteen years before The Sun Trip sent solar bikes across Eurasia, the Solartaxi proved that a sun-powered vehicle can cross continents.

Technical data

Builder	Louis Palmer & team, with four Swiss universities (HTA Lucerne and others)
Vehicle	Two-seat electric three-wheeler + solar trailer
Weight	~500 kg (car) + ~250 kg (trailer)
Solar	~6 m² silicon cells on the trailer
Consumption	~8 kWh / 100 km
Top speed	90 km/h
Journey	4 Jul 2007 – 18 Dec 2008, Lucerne → Lucerne, 54,000 km, 38 countries