Solar vehicle manufacturer unveils design for 'Sion' solar-electric car and 'Solar Bus Kit' intended for use in public transportation fleets.
The Sion, a groundbreaking solar electric vehicle (SEV) engineered by Munich-based Sono Motors, was designed to be an affordable and sustainable mobility solution. The Sion was set to feature integrated solar panels for supplemental charging, aiming to reduce or eliminate the need for external charging in daily use [1].
However, as of August 2025, the Sion project has been scrapped, with Sono Motors refocusing its efforts towards solar solutions rather than continuing SEV production [2]. Despite this, the company is still making strides in the solar-powered vehicle market, which is projected to grow significantly from USD 125.6 million in 2025 to USD 400.7 million by 2035 worldwide [1].
In addition to the Sion, Sono Motors has developed the Solar Bus Kit, a scalable B2B retrofit solution designed for public transport buses. This innovative product aims to integrate solar power into common 12-meter public transport bus types on the European market, including Mercedes-Benz Citaro and MAN Lion's City [1]. The Solar Bus Kit represents a milestone on Sono Group N.V.'s path towards a world without fossil fuels.
The Solar Bus Kit features approximately 8 square-meters of solar panels and a ~1.4 kW peak installation [1]. This solution allows subsystems like the heating, ventilation, and air conditioning (HVAC) system to be partially powered by renewable energy, saving fuel, CO2, and costs [1]. Bus fleet operators can potentially see a payback time of approximately 3-4 years with the Solar Bus Kit, as it can save up to 1,500 liters of diesel and up to 4 tonnes of CO2 per bus per year [1].
Sono Group N.V. is partnering with several companies worldwide to implement its Sono Solar Technology on a variety of vehicle architectures. Notable partnerships include MAN Truck & Bus and CHEREAU, as well as 19 other organizations [1].
In summary, while the Sion project is no longer active, Sono Motors continues to innovate in the solar-powered vehicle market. The Solar Bus Kit, a promising B2B retrofit solution, offers significant potential for reducing fuel consumption, greenhouse gas emissions, and costs in public transport. As the solar-powered vehicle market continues to grow, it is clear that Sono Group N.V. is at the forefront of this exciting and sustainable technology.
References:
[1] Sono Motors. (n.d.). Sono Motors. Retrieved from https://www.sonomotors.com/
[2] Sono Motors. (2025, August). Sono Motors announces the end of the Sion project. Retrieved from https://www.sonomotors.com/en/news/sono-motors-announces-end-of-sion-project/
- Science and technology are at the heart of Sono Motors' groundbreaking work, as they continue to innovate in the burgeoning solar-powered vehicle market, with projects like the Sion and the Solar Bus Kit.
- In the realm of environmental science, the Solar Bus Kit, a retrofit solution for public transport buses, is poised to make a significant impact by integrating solar power, reducing fossil fuel consumption, and lowering greenhouse gas emissions.
- As they partner with various organizations worldwide, Sono Group N.V., a leader in solar-powered vehicle technology, is leveraging finance and investing in business collaborations to expand their technology into diverse vehicle architectures, driving the global shift towards a cleaner, more sustainable future.
