Zero-emission cars are soaring in popularity but running an electric vehicle is next to impossible in places with limited charging infrastructure.
Stella Terra could change that.
The khaki-green SUV uses solar panels on its sloping roof to charge its electric battery, meaning it can drive long distances powered entirely by the sun.
Built by a team of students at Eindhoven University of Technology (TUE), “the world’s first off-road solar-powered vehicle” could help connect remote areas “where roads are less developed and energy grids are not as reliable,” and assist with emergency aid and deliveries, says Thieme Bosman, events manager for the team.
The team tested the vehicle in Morocco earlier this month, driving more than 1,000 kilometers (621 miles) between the country’s northern coast and the Sahara Desert in the south.
“Morocco has a huge variety of landscapes and different surfaces in quite a short distance,” says Bosman, adding that the car was tested “on every type of surface that a car like this could encounter.”
The road-legal car has a top speed of 145 kilometers (90 miles) per hour. On a sunny day, its battery range is around 710 kilometers (441 miles) on roads, and around 550 kilometers (342 miles) off-road, depending on the surface. In cloudy conditions, the team estimates the range could be 50 kilometers less.
Bosman noted that the vehicle had proved to be one-third more efficient than expected on the trip, and that its lightweight design made it less liable to get stuck on rugged terrain, and put less stress on its suspension.
Solar innovation
Electric SUVs are heavier than standard electric vehicles, and require bigger, heavier batteries to power them.
“Where the SUV market currently innovates on the previous models, we really start from scratch and design everything ourselves,” says Bosman. Minimizing the vehicle’s weight was essential, and the team of 22 students focused on making every element ultra-efficient. At just 2,645 pounds (1,200 kilograms), Stella Terra weighs around 25% less than the average mid-sized SUV.
The aerodynamic design also reduces drag and uses “lightweight and robust” composite materials to cut weight, says Bob van Ginkel, technical manager for Stella Terra.
“(One of) the benefits of the solar panels on top is that we can have a much smaller battery because we are charging while driving,” van Ginkel adds.
Able to travel off-road, and with no need for charging points, drivers of a solar-powered SUV are liberated to go where they please, says van Ginkel. The only restriction, he says, is “what are you going to do when you want to sleep?”
To answer that question, Stella Terra builds on the idea of the solar-powered campervan produced previously at the university, and the designers made elements of the SUV livable for long-distance, multi-day journeys: for example, the car’s seats fully recline to create a bed. When the car is stationary, the solar panels can be extended to maximize charging, while doubling as an awning for shade.
Bosman says the team also designed highly efficient solar panel converters, which he hopes could be beneficial to the wider solar industry.
Mountain tops to desert dunes
After unveiling a prototype of the SUV in September, the team traveled to Morocco to test the car on a range of off-road terrains.
Starting in Tangier, the team passed through the rugged Rif mountain range, where the rapid ascents and descents tested Stella Terra in its first off-road challenge.
Heading south through Fes, the team tested the car on the mountain trails of Midelt — one of Morocco’s highest towns — and ended their trip in the Sahara Desert, challenging Stella Terra on looser, sandy tracks.
Early in the journey they suffered a setback when the steering system broke, but they were able to find new parts and repair the vehicle in a local workshop.
Bosman said that the highlight of the trip was “the huge range of landscapes and surfaces that we’ve been on. Every hour of driving has been completely different. That really allowed us to test a lot, but for the team it has also been an incredible journey coming here.”
The trip was unaffected by the massive earthquake that hit Morocco in early September, but because of the huge impact the disaster had on the country, the Stella Terra team decided to join forces with The Red Cross on a crowdfunding campaign to help those affected.
Concept to reality
TUE’s automotive innovation lab has been experimenting with solar-powered vehicles for over a decade, producing concept cars that are typically “five to 10 years ahead of the market,” says Bosman.
A major challenge is turning the concept car into one that can be mass-produced. Alumni from the first TUE Solar program student team announced in 2022 that their company Lightyear was beginning production of a car fitted with solar panels. Earlier this year, the company filed for bankruptcy, before relaunching months later to focus on a new, cheaper model.
Bosman and his peers hope their concept SUV could be mass produced in the near future. “We aim to also inspire not only everyday people, but also the automotive industry, the Ford and Chryslers of the world, to think again about their designs and to innovate faster than they currently do,” says Bosman.
“It’s up to the market now, who have the resources and the power to make this change and the switch to more sustainable vehicles.”