Wärtsilä has been appointed as the electrical integrator for a significant battery enhancement initiative for the Wasaline ROPAX ferry 'Aurora Botnia'.
The initiative will upgrade the ship's battery capacity from 2.2MWh to 12.6MWh, which is claimed to be the world's largest operational marine battery hybrid system.
The enhancement project was booked in the third quarter of 2025.
The Aurora Botnia is equipped with dual-fuel engines and batteries. It utilises biogas and batteries for its propulsion.
The upgrade, set for commissioning in early 2026, includes the delivery of an Energy Management System, power drives, and control system integration.
Wasaline managing director Peter Ståhlberg said: “Wasaline’s commitment to decarbonised shipping operations is central to everything we do. In this, our close cooperation with Wärtsilä is an essential element that benefits not only both our companies, and we can see that our cooperation sets standards for the whole marine sector.
“Through our continued collaboration, the ‘Aurora Botnia’ has become a working example of what is possible when it comes to delivering environmentally friendly transportation within shipping.”
This project bolsters the ongoing partnership between Wärtsilä and Wasaline, with the Aurora Botnia serving as a floating laboratory linked to Wärtsilä's Sustainable Technology Hub.
This enables the refinement of hybrid technologies to optimise fuel efficiency and reduce exhaust emissions.
Wärtsilä marine and executive vice president Roger Holm said: “Wasaline once again demonstrates its strong commitment to decarbonisation by extending the electrification capacity of this ferry.
“Our latest contribution will optimise the ship's operations even further, creating fuel savings and a significant reduction in emissions.”
Launched in 2021, the Aurora Botnia is equipped with four Wärtsilä 31DF engines, known for their ultra-low emissions.
The engines have significantly curtailed methane emissions, allowing the ferry to ply between Vaasa, Finland, and Umeå, Sweden, with minimal environmental impact.
In a related advancement, Wärtsilä's retrofit package on the Corsica Linea ferry 'Pascal Paoli' has yielded fuel savings of up to 22%, according to the company’s statement.
This translates to cost savings of around $7,700 per journey, marking a milestone in Corsica Linea's decarbonisation journey and adherence to strict emission regulations.







