The Success of Stella Terra with Protean In-Wheel Motors

Solar Team Eindhoven, from the Eindhoven University of Technology, recently introduced Stella Terra, a groundbreaking solar-powered on and off-road vehicle — an innovation made possible through the integration of Protean’s in-wheel motors.

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

Why In-Wheel Motors?

In-wheel motors, also known as hub motors, offer a multitude of benefits to vehicles. Namely, superior packaging, as by removing a central drivetrain, there is more space for batteries, vital for a solar vehicle. Such is the level of energy provided by the solar panels and the battery storage on the car that it can provide sufficient electricity for cooking and charging devices such as a phone or camera.

Additionally, they provide improved aerodynamics and reduced weight, all contributing to better mileage, crucial in a solar-powered vehicle, as well as simplifying the drivetrain, reducing the number of parts needed, lowering weight, and minimizing the need for servicing or the risk of something going wrong.

Specifically, Protean’s in-wheel motors were chosen for Stella Terra for several compelling reasons. The motors demonstrate exceptional performance relative to their size and weight, and the integrated inverter resulted in considerable time savings during the design and testing phase. The weight of the Protean motors, a mere 75 kg in a total vehicle mass of 1200 kg, not only contributed to the car’s efficiency but also made energy consumption more efficient. The SolarTeam project manager noted a remarkable 65% reduction in the time needed to implement the drivetrain compared to previous projects.

Furthermore, the robustness and safety standards of the motors met the rigorous requirements set by Solar Team Eindhoven. Niels, SolarTeam’s Electrical Engineer, said that the collaboration allowed the project to move forward swiftly and successfully: “We had scheduled a week to test the Protean PD18 in combination with our drivetrain controller on a test bench, but thanks to the outstanding design and datasheets, we were able to perform all these tests in just one day.”

The Remarkable Journey

Stella Terra undertook an arduous expedition through Morocco and the Sahara, covering over 1000 kilometers across a range of terrains, from challenging sand dunes to rocky riverbeds. The vehicle’s performance remained unwavering, even in the face of scorching desert heat and steep 20-degree slopes. The efficient cooling system integrated into the Protean motors was instrumental in ensuring peak performance throughout the journey. The ProteanDrive in-wheel motors played a vital role in achieving this extraordinary feat, supplying the power and reliability necessary for off-road adventures. With peak power of 90 kW and peak torque of 1400 Nm, they effortlessly navigated the demanding terrain, showing no signs of performance degradation or braking issues, while regenerative braking was maximized for efficiency.

ProteanDrive is in low-volume production, ready to fulfill immediate demand for automotive and industrial applications. ProteanDrive motor designs can be further optimized for customer solutions — including improving power and torque, packaging, and weight optimization. Please contact us to discuss your requirements.

Solar Team Eindhoven

Solar Team Eindhoven builds innovative, efficient cars powered by the sun every two years. The team has previously won the World Solar Challenge in Australia four times in a row, competing in the family car class (Cruiser Class). In 2021, the team made headlines worldwide by building a solar-powered campervan, Stella Vita, and traveling to the southernmost point of Europe with it.

Protean Electric

Protean Electric is an automotive technology innovator, and a world-leading developer of in-wheel motors including ProteanDrive, a fully integrated in-wheel drive solution. Protean Electric’s technology is strategically positioned to play a key role in the hybrid & electric vehicle and future mobility market by offering a combination of packaging advantages, new vehicle design opportunities, performance benefits and earnings improvements. Globally Protean Electric has over 300 patents across 75 patent families with operations in the United Kingdom, China and the USA. Protean Electric is part of the BEDEO Group, a leading technology company that brings smart, sustainable transportation solutions to companies across Europe as they transition on the path to zero emission mobility.