[itismetheidiot]

if this ship is purely wind powered and basis on the published info this seems to be the case, i.e. there is no main engine of any type/fuel for propulsion - commercially it’s not viable. Shipping is highly optimized for arrival to a destination/port on a very narrow time window. Even delays of a couple of hours will be extremely expensive. For example, late arrival to SUEZ means that the vessel will join the end of the convoy at a premium rate costing hundreds of thousands of USD in additional fees. Not only that, Ports and Charterers (Liners) are working basis specific arrival times, you cannot simply arrival late because the wind was not favorable. It could work as an assisting system, such as Flettner rotors , skysails ,etc

[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.

[wiz21c]

I understand what you say. But maybe it's time to forget about that kind of time optimization and replace it by an optimization for fuel efficiency... Else we'll be stuck in the past...

(but I'm an idealist, for sure :-))

[newsclues]

If fuel savings are great enough, this could be irrelevant, and planned around.

And there could be a premium for the service. I could see Tesla paying extra to ship electric cars with burning bunker fuel. As a customer I’d pay extra for that.

[grkvlt]

Well, their website claims "90% lower emissions than a vessel with a diesel engine" so evidently they use some form of engine, or they'd be claiming 100% lower! i would guess it's like most sailing boats, and it has a small(-ish) engine and prop for use when docking/maneuvering up close/no wind, and also a genset for onboard electrical power.

[canniballectern]

You'd probably do the same thing that powered ships do: build extra time into the schedule so that you never arrive late. This ship probably needs more padding because it relies on the wind, but the whole concept seems to be that that's an acceptable tradeoff for the environmental gains.