The Aurora Botnia, a short-sea ro-ro ferry that features a hybrid electric power and propulsion solution, is nearing handover before starting operations in the northern Baltic Sea.
The vessel is expected to run primarily on LNG, backed up by batteries and a fuel mix that will soon include liquefied biogas. When this is implemented, it is estimated that the ferry’s CO2 emissions will be 50% lower than those of a traditionally powered vessel, and the fuel costs 40% lower.
Two 5.8MW Azipod electric propulsors and other consumers on the vessel gain power from four aggregates driven by dual-fuel variants of Wärtsilä’s 31-series medium-speed engine, which can run on biofuel or LNG.
Wärtsilä’s eight-cylinder W31DF engines can produce 4,800kW at a crankshaft speed of 750rpm, and feature common-rail injection and two-stage turbocharging. The company also provided two LNG storage tanks, fuel supply and control systems, maneuvering thrusters fore and aft, automation, catalyzators and a Nacos Platinum navigation system.
A 2.3MWh energy storage system consisting of batteries made by Leclanché provides the ship with zero-emission power for use in port maneuvers, enabling a peak-shaving role that saves generator usage. Danfoss AC drives control the main power grid, the electric motors and the DC connection of the batteries to the propulsion system.
With an 800-passenger capacity and a 1,500 lane-meter capacity for vehicles, the Aurora Botnia will operate on Kvarken Link’s Wasaline service between Vaasa in Finland and the Swedish port of Umeå.
When carrying out daily operations, the ferry will be linked to a Wärtsilä smart technology hub on land to monitor performance for sustainability.