Wärtsilä powers largest marine battery

The work will increase the Aurora Botnia’s battery capacity from 2.2 MWh to 12.6 MWh, reportedly creating the world’s largest marine battery hybrid system in operation. The order was booked in Q3 2025, and commissioning is set for early 2026.

“Wasaline’s commitment to decarbonised shipping operations is central to everything we do,” said Peter Ståhlberg, managing director of Wasaline.

“Our close cooperation with Wärtsilä is an essential element that benefits both our companies, and we can see that our cooperation sets standards for the whole marine sector.”

Combining energy storage with dual-fuel engines, the Aurora Botnia already runs on biogas and electricity, making it one of the world’s most environmentally advanced ferries.

Wärtsilä’s scope includes delivering the energy management system, upgrading power drives and integrating control systems.

The Aurora Botnia also functions as a floating testlab, connected to Wärtsilä’s Sustainable Technology Hub, advancing hybrid marine technologies and optimising emissions performance.

“Our latest contribution will optimise the ship’s operations even further, creating fuel savings and a significant reduction in emissions,” said Roger Holm, president of Wärtsilä Marine.

Since entering service in 2021, the Aurora Botnia has operated between Vaasa, Finland and Umeå, Sweden, featuring four ultra-low emission Wärtsilä 31DF engines, which significantly cut methane emissions.