Wärtsilä to Integrate Battery Extension for Wasaline Ferry
Wärtsilä has been selected as the electrical integrator for a major battery extension project for the Wasaline ROPAX ferry "Aurora Botnia." The project will increase the ship’s battery capacity by 10.4 MWh, from 2.2 MWh to 12.6 MWh, making it the world’s largest marine battery hybrid system in operation. The order with Wärtsilä was booked in Q3 2025.
In the transition to more sustainable ferry transportation, hybrid propulsion systems have emerged as a compelling solution, offering a multitude of pathways to reduce greenhouse gas (GHG) emissions. These systems, which combine energy storage capabilities with conventional engines, can significantly cut fuel consumption and, consequently, emissions.
The Aurora Botnia ferry, which is operated by Wasaline, is equipped with dual-fuel engines and batteries and is using biogas and batteries for the propulsion. Expanding its battery capacity is a major step in making the ship even more sustainable. Wärtsilä will lead the integration project and as a result, the battery capacity of the ferry will be extended by 10.4MWh. Wärtsilä will also deliver the Energy Management System, as well as upgrade the power drives and the control system integration. The system is scheduled to be commissioned in early 2026.
This latest project will strengthen the existing collaboration agreement between Wärtsilä and Wasaline, with the Aurora Botnia acting as a floating testlab linked to Wärtsilä’s Sustainable Technology Hub. It allows further development of hybrid technologies to optimise fuel efficiency and minimise exhaust emissions. As a result, the vessel is one of the most environmentally sustainable ferries in the world, operating carbon neutrally already today.
The Aurora Botnia, which entered into service in 2021, operates with a range of integrated Wärtsilä solutions, including four highly efficient Wärtsilä 31DF engines. The ultra-low emissions version of the engine has helped the ferry to significantly reduce methane emissions. The ferry operates between Vaasa in Finland and Umeå, Sweden.