Naval architecture and engineering consultancy Foreship is supporting Wasaline in delivering a breakthrough battery upgrade on 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 per cent.
Building on a long-standing relationship with Wasaline that began during the vessel’s initial design phase, Foreship provided comprehensive technical and strategic support for the retrofit. 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,” said Joonatan Haukilehto, Head of New Technologies at Foreship. “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.”
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 per cent 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.
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.
Foreship expects to provide ongoing assistance during the detail engineering, installation, and commissioning phases, including technical oversight, site supervision, and functional integration support. The company’s work on Aurora Botnia builds upon more than a decade of pioneering battery and hybrid system design for ferries, cruise ships, and specialized vessels, with over 60 battery system projects completed.
