A recent article in Sjöfartstidningen tells the story of how marine electrification is becoming a practical solution for various types of coastal transport. And Metstech played a critical role in the two conversions mentioned.
The first case study is Lyrön, an older passenger vessel that has been rebuilt for hybrid-electric operation, and the second is Härön, a small island ferry that has been converted for battery-electric service.
Together, these vessels demonstrate that electrification is no longer confined to newly built ferries. It is also becoming an attractive retrofit option for older vessels whose routes, speed profiles and operating patterns make lower-emission propulsion both technically and commercially viable.
Lyrön was a more technically demanding project. Built in 1973, it has been con
verted from conventional propulsion to a parallel hybrid arrangement, retaining its twin Scania DI13 diesel engines while integrating a 50 kW electric motor and 285 kWh of marine battery capacity. Charging from shore takes around seven hours. The battery installation is enclosed in a fire-insulated compartment with temperature, smoke, and gas monitoring. This demonstrates that the retrofit was designed with performance, compliance, and onboard safety in mind.
What makes Lyrön especially interesting is that the propulsion system had to be fitted into a vessel built over fifty years ago with limited machinery space, meaning the existing driveline had to be adapted rather than replaced.
Metstech supplied the complete electric propulsion package, including automation, charging and energy management functions. This makes the project significant beyond one vessel. It suggests that smaller Scandinavian passenger ships could be modernised in stages to enable silent, low-speed operation and reduce fuel consumption, while retaining the flexibility of a diesel backup for longer or less predictable voyages.
The second case study concerns the ferry Härön and illustrates a different electrification logic. This ferry operates on the short Kyrkesund–Härön route, which takes only a few minutes. For this reason, full battery-electric propulsion is preferable to hybrid. The Härön now runs with two Danfoss electric motors and 105 kWh of battery capacity. It charges between trips and fully recharges overnight when laid up. As the timetable is predictable and the distance travelled is very short, the vessel can operate as part of an integrated transport-energy system, using berthing time for charging.
Further information reveals that Härön is part of a significant shift towards public transport on Tjörn. In 2023, Västtrafik announced that all ferry traffic in the area would be fully electrified. Tjörns kommun later confirmed that Metstech would supply the new charging stations with around 1,000 kWh of battery capacity.
We congratulate Sjöfartstidningen on its excellent coverage and thank the publication for featuring Metstech‘s work!