Solar-powered off-road car finishes 620-mile test drive across north Africa

The Stella Terra was designed by students at Eindhoven University of Technology and completed trip without recharging

A solar-powered car said to be the first in the world capable of driving off-road over long distances without recharging has completed a 620-mile (1,000km) test drive across Morocco and the Sahara.

The two-seat Stella Terra, designed by students at the Eindhoven University of Technology, completed the journey across a variety of challenging landscapes as part of a final test of its lightweight frame and aerodynamic profile.

The car, which runs off the energy provided by multiple solar panels on its roof, has a top speed of 90mph (145kmph), weighs only 1,200kg (1.2 tonnes) and has a range of at least 440 miles (710km) on a sunny day.

Wisse Bos, team manager of Solar Team Eindhoven, said the technology used, complementing a lightweight frame with highly efficient solar panels, was a decade ahead of anything on the market.

He said: “Stella Terra must withstand the harsh conditions of off-roading while remaining efficient and light enough to be powered by the sun. That is why we had to design almost everything for Stella Terra ourselves, from the suspension to the inverters for the solar panels. We are pushing the boundaries of technology.”

The car contains a rechargeable lithium (Li)-ion battery, which would also allow it to operate in less sunny climates but over shorter distances. Such is the level of energy provided by the solar panels on the car that it can provide sufficient electricity for cooking and charging devices such as a phone or camera.

Aged between 21 and 25, the 22 students behind the car brought the project to life after taking a year off from their studies.

The steering system on the olive-green car failed during the week-and-a-half-long experiment in the dry and varied landscapes of north Africa, from Tangier to the Sahara, but it was swiftly put right, according to Bob van Ginkel, 24, the project’s technical manager.

He said: “We hope this can be an inspiration to car manufacturers such as Land Rover and BMW to make it a more sustainable industry. The car was actually very comfortable in the off-road conditions as it is very light and does not get stuck.”

The car’s bespoke converter was found to be 97% efficient in turning sunlight absorbed by the solar panels into electrical charge. Stella Terra was a third more efficient than had been originally envisioned. The most efficient panels on the market generally reach about 45% efficiency, while most panels are about 15% to 20% efficient.