Foreship to help Wasaline up hybrid ferry’s energy storage capacity almost sixfold

Finland-based naval architecture and engineering consultancy Foreship has been contracted to support compatriot shipping company Wasaline in delivering a battery upgrade on MV Aurora Botnia that will see the ferry’s energy storage capacity increase nearly sixfold.

The ‘world-first’ retrofit will combine two battery chemistries in a hybrid solution that is expected to cut annual CO₂ emissions by up to 23%.

As informed, Foreship provided comprehensive technical and strategic support for the retrofit, building on the collaboration that began during the vessel’s initial design phase. The work included an extensive feasibility study covering technical impact evaluation, emissions modelling and cost analysis, later followed by supplier evaluation, classification design, engineering support, and implementation assistance.

“This is one of the most technically ambitious hybrid conversions yet attempted on a ro-pax ferry,” Joonatan Haukilehto, Head of New Technologies at Foreship, explained.

“By integrating high-power NMC batteries with energy dense LFP batteries, we have enabled Aurora Botnia to draw on the unique strengths of both battery chemistries. All of this has been achieved without requiring major changes to the vessel’s electrical infrastructure. To our knowledge, it is the first time this dual-battery approach has been realized in a maritime retrofit.”

According to Foreship, the upgrade increases the vessel’s total battery capacity from 2.2 MWh to 12.6 MWh. Scheduled for commissioning in early 2026, and recharged by renewable shore electricity during port stays, the enlarged battery setup will supply up to 20% of the vessel’s total energy demand. This will deliver enhanced energy efficiency throughout its 1,000-plus annual voyages by enabling the LNG-fueled powerplant to operate continuously at its highest efficiency, while using the minimum number of generating sets. Quayside power use is already zero emissions, thanks to the shore power infrastructure at both ports of call.

Specifically, Foreship supported Wasaline in optimizing the retrofit for commercial and regulatory impacts. Using emissions modelling aligned with the EU Emissions Trading System and FuelEU Maritime, the consultancy demonstrated how the combination of the new battery capacity with existing LNG and bio-LNG fuel use could enable compliance through to the 2040s. It also creates opportunities for Wasaline to sell surplus emission allowances.

“From the beginning, Aurora Botnia was built to evolve, and Foreship has been with us at every step of that journey,” Peter Ståhlberg, Managing Director of Wasaline, said.

“This latest upgrade represents a significant leap toward our 2030 climate goals. By integrating advanced battery solutions and maximizing our use of clean shore power, we are proving that sustainable ferry transport is wholly viable.”

Furthermore, Foreship is expected to provide ongoing assistance during the detail engineering, installation, and commissioning phases, including technical oversight, site supervision, and functional integration support.

Built by Rauma Marine Constructions, the LNG-fueled ferry Aurora Botnia was delivered to Wasaline back in August 2021.

During the ship’s first year of service, Wasaline was able to cut total CO2 emissions by 51.8 percent.

Last month, the company unveiled plans to achieve further GHG emission cuts by expanding the onboard battery capacity of the hybrid ferry. Aurora Botnia’s battery capacity will be enhanced by an additional 10.4 MWh with batteries from Andorra-based AYK Energy.