Hittfeld, November 3rd, 2026 – Lehmann Marine, a Sunlight Group company, has delivered another major electrification milestone: turning the MS SISSI passenger ship fully electric. Converted from traditional diesel in collaboration with operator Donauschifffahrt Wurm & Noé and ÖSWAG Werft, the Passau vessel with a length of 46.8 metres and a capacity of 250 passengers is now operating with zero local emissions.
To power the high-frequency daily passenger routes through the rivers‘ heavy currents, Lehmann Marine installed its custom 2,000 kWh CUBE battery system. The system provides maximum safety, flexibility, and operational reliability while optimising space utilisation onboard the vessel – and adds silent cruising to the travel experience of the passengers on board.
MS SISSI, Picture (C) Donauschifffahrt Wurm & Noé
”Electrifying a vessel like the MS SISSI proves that decarbonising European waterways doesn‘t require scrapping active fleets – it’s about empowering them with the right technology“, explains Matthias Schubert, Head of Sales at Lehmann Marine. ”Built to the highest international maritime safety standards, our CUBE battery system delivers a zero-emission solution that provides the thermal stability and power required to navigate the strong currents of the Danube and Inn – all optimised for tight onboard spaces and well accessible for easy maintenance and service.“ Decarbonising active fleets on these waterways offers immediate environmental benefits, drastically cutting exhaust emissions and eliminating engine vibration and noise along densely populated waterfronts.
Florian Noé, Managing Director of Donauschifffahrt Wurm & Noé, adds: „For more than 25 years, our MS SISSI has been a cherished piece of regional transit along the Danube and Inn. Transitioning an iconic vessel to fully electric power requires absolute confidence in both safety and system endurance. Lehmann Marine’s battery architecture gives us the exact reliability, fast-charging capacity, and safety safeguards needed to run dense daily schedules without interruption. Beyond the technical achievement, the immediate impact on our passengers and local environment is extraordinary – zero exhaust emissions and a completely silent cruising experience that respects the natural river ecosystems we operate in.“
This milestone highlights the growing impact of Lehmann Marine and Sunlight Group in the maritime sector – demonstrating how smart energy infrastructure can support municipal transit, protect fragile ecosystems, and power high-frequency commercial transport.
CUBE Installation
About Lehmann Marine GmbH: Lehmann Marine is a Germany-based leader in the shipping industry’s advanced lithium iron phosphate (LFP) battery systems. The company’s innovative energy solutions are designed to meet the evolving needs of maritime operators, offering safety, reliability, and sustainability through cutting-edge German engineering. The key to success lies in the well-thought-out concept of Lehmann Marine‘s battery systems. The modular and flexible design allows for easy adaptation of the batteries to the individual requirements of various ships. This configurational flexibility, combined with straightforward maintenance due to small and easily accessible battery modules, gives customers unprecedented efficiency and reliability. Another significant advantage is the enhanced safety of lithium iron phosphate (LFP) cells. Compared to traditional nickel-manganese-cobalt (NMC) batteries, LFP batteries are considerably safer, even in extreme situations where thermal runaway may occur, as they are not susceptible to fire. In the event of thermal runaway, only gas is released and vented outside. This feature renders Lehmann Marine‘s LFP battery solutions more environmentally friendly and markedly safer for use on board ships. Lehmann Marine is part of the Sunlight Group, a major global player in energy storage systems, and benefits from Sunlight’s large capacities and excellent supplier and service network. For additional information, please visit: https://lehmann-marine.com/