Lightyear and Volkswagen Development with Group Innovation collaborated on the integration of vehicle-integrated solar technology into Volkswagen’s Mission Efficiency, a near-production electric vehicle designed to push the limits of efficiency. As part of the project, Lightyear developed a 370 W photovoltaic system integrated into the vehicle’s glass roof and rear window, contributing up to 30 km of additional driving range per day. The collaboration brought Lightyear’s solar expertise into a real automotive development programme, with solar integration considered alongside the vehicle’s design and engineering requirements from an early stage.
Mission Efficiency: pushing the limits of electric mobility
Volkswagen developed Mission Efficiency to explore how much energy an electric vehicle can save through its overall design and technology. During a 1,278.36 km journey from Wolfsburg to Vienna, Mission Efficiency vehicle achieved an average consumption of 6.89 kWh/100 km without charging losses and completed the journey with just one charging stop. The project therefore brought solar generation into a vehicle programme where efficiency was a central design objective.
Vehicle-integrated solar technology in the glass roof and rear window
Lightyear’s vehicle-integrated photovoltaic (VIPV) technology was integrated directly into the vehicle’s glass roof and rear window. With a total output of 370 W, the system generates electricity from sunlight and supplies it to the vehicle’s on-board electrical system through Lightyear’s Power Electronics. Under suitable conditions, the solar system can contribute up to 30 km of additional driving range per day. The semi-transparent solar panels also allow natural light into the cabin while making use of the glass surfaces to generate solar energy. For Lightyear, the project involved integrating solar technology into the vehicle from an early stage. The team worked with Volkswagen on the position and orientation of the solar cells, as well as requirements around transparency, appearance and the geometry of the glass.
Developing the solar integration
The project started towards the end of summer 2025, when Lightyear began working with Volkswagen on the solar integration. The team developed the first prototypes and worked on the shape of the glass around the solar integration. The first solar panels were shipped to Volkswagen towards the end of the year, followed by further development and integration work as the vehicle programme progressed.
Nelis Geurts, Lightyear’s Solar Engineer, was closely involved in the development of the solar system:
“Mission Efficiency allowed us to show our strength. You can have the best of both worlds: a high efficiency panel increasing the range of the car, but also an aesthetically pleasing look which is one with the design of the car.”
He worked alongside Lightyear’s wider project team to bring together the solar and electronic aspects required for the vehicle integration.
Why vehicle-integrated solar matters
Mission Efficiency provides a concrete example of how vehicle-integrated solar can become part of an electric vehicle’s design and energy system from the development stage.
By integrating solar into the glass roof and rear window, the project shows how photovoltaic technology can contribute to vehicle efficiency while preserving the design and functionality of the vehicle.
For Lightyear, the collaboration demonstrates the potential of making solar an integrated vehicle option, combining high-efficiency solar technology, Power Electronics and vehicle design in one solution.
