Finland | Sweden – 27 August 2025 – In a groundbreaking stride towards sustainable maritime operations, technology group Wärtsilä has been selected as the electrical integrator for an ambitious battery capacity expansion project on Wasaline’s ROPAX ferry ‘Aurora Botnia’. This project will elevate the vessel’s battery capacity from 2.2 MWh to an unprecedented 12.6 MWh, making it the world’s largest marine battery hybrid system in operation—a milestone moment in maritime decarbonisation.
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A Quantum Leap in Sustainable Marine Technology
This cutting-edge initiative is not merely an upgrade—it’s a signal to the global shipping industry that next-generation, low-emission operations are not only possible but practical.
Wärtsilä’s role is critical: the group will lead the integration of the massive 10.4 MWh battery extension, supply the Energy Management System (EMS), upgrade the power drives, and seamlessly incorporate the control systems. The entire system is expected to be commissioned in early 2026, positioning the Aurora Botnia as a floating beacon of sustainable shipping.
“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 essential—not only for our companies but for setting a standard across the entire maritime sector.”
From Innovation to Emission Elimination
Hybrid propulsion systems represent a pivotal solution in the shipping industry’s transition to a cleaner future. By blending advanced energy storage with traditional engines, these systems drastically reduce greenhouse gas (GHG) emissions, fuel consumption, and operating costs.
The Aurora Botnia, launched in 2021, is already a leader in green propulsion. Equipped with Wärtsilä’s dual-fuel engines capable of running on biogas, as well as its original battery systems, the ferry has earned global recognition for sustainability. With the new upgrade, it edges even closer to carbon-neutral operations on every voyage.
A Floating Innovation Lab
Beyond commercial operations, the Aurora Botnia now serves as a floating test lab, directly linked to Wärtsilä’s Sustainable Technology Hub in Vaasa. This innovative partnership enables continuous testing and refinement of hybrid technologies, allowing for real-time optimization of fuel efficiency and emission reductions.
“Wasaline once again demonstrates its strong commitment to decarbonisation,” said Roger Holm, President of Wärtsilä Marine & Executive Vice President, Wärtsilä Corporation. “Our latest contribution will further optimize the ship’s operations, delivering both fuel savings and substantial emission cuts.”
The Aurora Botnia operates daily between Vaasa, Finland, and Umeå, Sweden, supporting vital freight and passenger services in the region. It is the northernmost shipping line in the world—and arguably one of the most innovative.
With four state-of-the-art Wärtsilä 31DF dual-fuel engines, widely acknowledged as the most efficient of their kind, the vessel has already made significant strides in reducing methane slip and NOx emissions. The new hybrid battery upgrade raises the bar even further, showcasing a model that others in the industry will be closely watching—and likely emulating.
About Wasaline
Wasaline is the northernmost shipping line in the world, providing daily passenger and freight service between Vaasa (Finland) and Umeå (Sweden). The company is at the forefront of sustainable shipping with its flagship ferry, Aurora Botnia, equipped with dual-fuel engines, biogas capabilities, and battery hybrid propulsion.
The ferry and the company have been awarded the Key Flag Symbol, a mark of excellence and recognition for Finnish-made products and services. Wasaline is more than a ferry operator—it’s a symbol of Nordic innovation, sustainability, and reliability in maritime logistics.
Wärtsilä at a Glance
With a history of engineering excellence, Wärtsilä is a global technology leader with a focus on sustainability and innovation in the marine and energy sectors. With 18,300 professionals across 77 countries, Wärtsilä is actively shaping the decarbonisation journey of entire industries.
In 2024, Wärtsilä posted EUR 6.4 billion in net sales and continues to grow its global impact through investments in research, digitalisation, and green energy infrastructure.
About Wärtsilä Marine
Wärtsilä Marine is a global frontrunner in power, propulsion, and lifecycle solutions tailored for the maritime industry. The company spearheads the transition to new, sustainable fuels, pioneering a future where vessels and ports operate within a fully connected digital ecosystem.
Its product portfolio spans:
- High-efficiency engines and propulsion systems
- Advanced hybrid and battery solutions
- Exhaust gas treatment systems
- Shaft line and energy management solutions
- Integrated powertrains and automation
- Digital vessel optimization and AI-driven lifecycle support
Underpinned by performance-based service agreements and supported by one of the world’s largest maritime networks, Wärtsilä’s innovations are helping customers navigate a complex energy transition with reliability, safety, and sustainability at the forefront.
Source Wartsila Technology Group