Student-built, street-legal EV crosses 3,000km in Australia to win 2025 Bridgestone World Solar Challenge

The student-built Sophie 8X EV has won the 2025 Bridgestone World Solar Challenge race in the Cruiser class. Multiple teams competed with hand-built EVs to cross Australia from Darwin to Adelaide in a test of the latest technologies for solar-powered vehicles. Its preliminary record shows the winning Vocational Training Council (VTC) entry completing a total distance of 3,021.5 km (1,877.5 mi.) in 44.00 hours at an average speed of 68.7 kph (42.7 mph).

The race has once again demonstrated that the current crop of consumer EVs, such as Teslas, are overweight, wasteful examples of electric vehicles. For example, the Cruiser-class EVs weigh about 400 kg to 800 kg (880 to 1760 lbs.), whereas the Tesla Y weighs about 1,900 kg (4,200 lbs.). Sophie 8X uses a 15.2 kWh battery pack that weighs 40 kg (88 lbs.), and the Tesla Y uses a 60+ kWh battery pack that weighs over 770 kg (1,700 lbs.).

The roof of the dual-seat Sophie 8X is covered in 6 m² of solar cells, providing electricity to power the vehicle and charge the 15.2 kWh battery pack. The pack is made with 400 Wh/kg lithium battery pouches to conserve space.

Electricity is fed to custom-designed motors that use third-generation semiconductor SiC (silicon carbide) technology for improved energy conversion. According to the team, this provides a 30% reduction in energy consumption at 100 kph (62 mph). Computational fluid dynamics (CFD) analysis was used to help shape the lightweight carbon fiber body panels for reduced aerodynamic drag, further improving efficiency.

Unlike other competitors, the VTC Sophie 8X has been legally authorized to drive on public roads, a first for such an EV in Hong Kong, proving it has met automotive safety standards.

Readers frustrated by the poor efficiency of their current gas-powered vehicles can read up on how to hypermile with a ScanGauge to lower their fuel usage.