Sono Motors, the German solar-enhanced electric vehicle company, has developed a bus trailer topped with solar panels, which will be trailed in Munich shortly.

Developed in partnership with Munich’s public transport authority Münchner Verkehrsgesellschaft (MVG), the novel trailer incorporates 20 semi-flexible special photovoltaic (PV) modules, which can provide over 2,000 watts to power the vehicle’s battery and electrical loads such as heating, ventilation, air conditioning, and the trailer’s steering system.

According to Sono, the technology is suitable for integration into existing and new vehicles.
it offers an annual CO2 saving potential of more than 6.5 tonnes per bus, while providing additional passenger capacity.

“The partnership with MVG illustrates the enormous potential of our solar technology, which is being used for the first time on public transport. This is a milestone in Sono Motors’ mission to make every vehicle solar”, says Laurin Hahn, Sono Motors co-founder and CEO. “Especially in times of rising energy prices and increasing urban area emission regulations, our solar technology offers great added value for public transport operators.”

Sono estimates that for a medium-sized fleet of around 300 buses, the trailers could save around 2,000 tonnes of CO2 per year, and anticipates potential increases as both the solar cells and the power electronics become more efficient in the future.

The solar installation is optimised for vehicle integration using Sono’s proprietary power electronics. Millisecond optimisation of the multi-channel system is key to transferring photovoltaic yields to the bus battery.

Veit Bodenschatz, Managing Director and Head of Bus Division of the MVG says, “the photovoltaic system on our bus trailer now allows us to test under real conditions how well the power generation works and whether there are perhaps routes in our network that are better suited than others for this type of power generation. The question of what energy savings can be achieved by using solar energy are, of course, particularly exciting against the background of current fuel and energy prices”.

Speaking at the pilot project’s launch, Munich Vice Mayor Katrin Habenschaden said,  “Transport still misses the climate protection targets by a very wide margin and has a direct impact on air quality in Munich. The solar buses can be a cornerstone in this urgently needed change towards climate-friendly mobility. I am convinced by the idea, as a lot of fuel can be saved here, and CO2 emissions can be significantly reduced. We are already working with MVG to completely convert our bus fleet to electric drives. Harnessing the power of the sun is of course even more sustainable and I hope that this pilot project will show that we can also extend the range of the e-buses using solar energy.”