Posted on September 1, 2025
Technology group 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.
“Wasaline’s commitment to decarbonised shipping operations is central to everything we do,” says Peter Ståhlberg, Managing Director – Wasaline. “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 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.
“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,” comments Roger Holm, President of Wärtsilä Marine & Executive Vice President at Wärtsilä Corporation.
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.
Wärtsilä Marine in brief
Wärtsilä Marine is a global pioneer in power, propulsion and lifecycle solutions for the marine market. We develop industry-leading technologies, advancing maritime’s transition to new fuels. We support building an end-to-end digital ecosystem where all vessels and ports are connected. Ultimately, Wärtsilä Marine is driving the shipping industry forward on its journey towards a decarbonised and sustainable future through our broad portfolio of engines, propulsion systems, hybrid technology, exhaust treatment, shaft line solutions and digital technologies, as well as integrated powertrain systems. Our offering, which is underpinned by our performance-based agreements, upgrades, lifecycle solutions, decarbonisation services, as well as an unrivalled global network of maritime expertise, delivers the efficiency, reliability, safety, and environmental performance needed to support a safe and sustainable future for our customers, our communities and our planet.
www.wartsila.com/marine
Wärtsilä in brief
Wärtsilä is a global leader in innovative technologies and lifecycle solutions for the marine and energy markets. We emphasise innovation in sustainable technology and services to help our customers continuously improve their environmental and economic performance. Our dedicated and passionate team of 18,300 professionals in more than 230 locations in 77 countries is shaping the decarbonisation of our industries across the globe. In 2024, Wärtsilä’s net sales totalled EUR 6.4 billion. Wärtsilä is listed on Nasdaq Helsinki.
www.wartsila.com
Wasaline in brief
Wasaline is the northernmost shipping line in the world, which transports passengers and freight daily between Vaasa in Finland and Umeå in Sweden. The route is important for security of supply. The company’s hybrid ferry, Aurora Botnia, is equipped with dual-fuel engines and batteries. The Key Flag has been awarded both to Aurora Botnia and Wasaline’s services as a recognition of Finnish work. For more information, please visit www.wasaline.com
