The 80-meter vessel can carry 120 cars and 360 passengers. From 2015 onward, it will serve the route between Lavik and Oppedal, Norway, across the Sognefjord.
The vessel currently serving this route uses on average one million liters of diesel and emits 570 metric tons of carbon dioxide and 15 metric tons of nitrogen oxides a year.
The companies developed the electrically powered ferry for submission to a competition organized by Norway’s Ministry of Transport. As a reward for winning the competition, the shipping company Norled has been granted the license to operate the route until 2025.
Rather than a diesel engine, the ferry is equipped with electric motors to drive the ship’s two screws. These motors are powered by a battery weighing 10 metric tons.
The ship has been specially designed to fit the requirements of an electric drive system. As a catamaran with two slim hulls, it offers less resistance in the water than a conventional vessel. The hulls are also made of aluminum instead of heavier steel.
All in all, the new vessel weighs only half as much as a ferry of conventional design. This saving has a direct impact on the specifications of the drive system. Whereas the ferry currently serving the route has an engine with an output of 1,500 kW or more than 2000 horsepower, the battery in the new vessel will have an output of 800 kW. In normal conditions, operating at a speed of 10 knots, battery power of 400 kW will suffice, Siemens says.
Batteries powering the ship can be recharged in 10 minutes, meaning the craft can be “refueled” in the breaks between crossings, Siemens says. In the two small villages linked by the ferry, however, the local grid is not equipped to deliver such a large amount of power in such a short space of time. To deal with this problem, batteries have been installed at each port. These serve to recharge the ferry’s battery during turnaround and are then themselves slowly recharged from the local grid, Siemens says.
Currently hundreds of ferries link Norway’s mainland to the islands off its coast and provide routes across its fjords. This battery technology could be used to replace all ferries operating on crossings of 30 minutes or less, Siemens says.