[helsinkiandrew]

It has an ‘auxiliary engine’ for port manoeuvring and ‘emergency power’. This ship is being designed for the Atlantic route and I imagine will be sailing with the trade winds to get more consistent winds (Clockwise around the Atlantic). The reason this is being built for roro cars rather than traditional cargo is probably due to the logistics.

[VBprogrammer]

It seems pretty likely that this also has a significant amount of generator capacity on board. Even small sailboats often have to run their engine or generator during passages to top up their battery.