With potential savings of up to 2,500 liters of diesel per year and an annual local CO2 savings potential of over 6.5 tons per bus, the Sono solar technology on solar bus trailers is intended to contribute to climate protection and the reduction of inner-city greenhouse gas emissions. Twenty semi-flexible special photovoltaic modules (PV modules) are expected to deliver over 2,000 watts to power the vehicle battery, electrical consumers such as heating, ventilation, and air conditioning, as well as the trailer's steering system. Laurin Hahn, co-founder and CEO of Sono Motors, is optimistic:
“The partnership with the Munich Transport Company illustrates the enormous potential of our unique solar technology, which is now being used in public transport for the first time in the company's history. For Sono Motors, this is a milestone in its mission to equip every vehicle with solar cells. Especially in times of rising energy prices and increasing emissions regulations in urban areas, our solar technology offers significant added value for public transport companies. City buses and coaches – whether electric or diesel – offer a lot of space and are outdoors every day. The first solar bus trailer for the MVG will soon be on Munich's streets, allowing MVG passengers to experience solar mobility in daily use.
Testing under real conditions
The solar technology found on the solar bus trailer was developed and tested specifically for use on buses. The concept for the solar bus trailer was developed in collaboration with MVG to ensure maximum space utilization and efficiency. In addition to the solar installation optimized for vehicle integration, it also includes electrical integration using the power electronics (MPPT Central Unit), known as the MCU, developed by Sono Motors. The solar charge controller features an intelligent algorithm that optimizes the energy yields of the PV modules. Thanks to the ultra-fast optimization in the millisecond range and the multi-channel system, the PV yields can be optimally transferred to the bus's battery.
The modules cover a total area of twelve square meters and supply the 24V battery with over 2,000 watts. The solar energy generated in this way is used to operate the HVAC system (heating, ventilation, and air conditioning) and to support the trailer's steering system.
Veit Bodenschatz, Managing Director and Head of Bus at Munich Transport Company (MVG), says:
"With the photovoltaic system on our bus trailer, we can now test under real-world conditions how well power generation works and whether there are perhaps routes in our grid that are better suited than others for this type of power generation. The question of what energy savings can be achieved through the use of solar energy is, of course, particularly exciting given current fuel and energy prices."
Additional range through solar technology on the roof
The patented solar technology of Sono Motors has been developed to be integrated and licensed into a wide variety of vehicles.
"For e-buses equipped directly from the factory with our solar technology on the roof and sides, additional range can be generated through solar energy. This not only reduces downtime for charging but also protects the battery through a constant charging process. The e-bus can therefore be operated longer,"
explains Hahn.
Regular operation after technical approval
At the presentation of the solar bus trailer at the MVG depot West in Munich Laim, Munich's second mayor was also present Katrin Habenschaden guest:
"We need a change of course in the transport sector. Transportation is still falling far short of its climate protection targets, and this has a direct impact on the city's air quality, including in Munich. Solar buses can be a building block in this urgently needed shift toward climate-friendly mobility. I'm convinced by the idea because they can save a lot of fuel and significantly reduce CO2 emissions. We're already working with MVG to convert our bus fleet entirely to electric drives. Harnessing the power of the sun is, of course, even more sustainable, and I hope this pilot project demonstrates that we can also extend the range of e-buses with solar energy. What I'm particularly pleased about in this collaboration with our MVG is that such an innovative idea comes from a Munich-based company."
After technical approval by the responsible supervisory authorities, the bus trailer will go into regular operation and can be used by all Munich residents.
