[reliablereason]

Modern container ships are more like 3g per ton (page 5):

https://backend.orbit.dtu.dk/ws/portalfiles/portal/158911010...

6000km from France to NY

3g * 6000km * 350tones / 1000 / 1000 = 6.3 metric tones of CO2.

I don't know how much disel the sail ship might use, but 6.4 tones of C02 is equivalent of 1974L of disel.

According to their own website https://graindesail-logistics.com/en/ they aim for 1.8 g off CO2 per km per ton.

1.8 is lower than 3g. If those aims are reached I guess they are "more green" than I thought. But the gain is quite small, if you truck that cargo for 160km all the CO2 savings are gone. A modern truck emits 45g of CO2 per km.

[evomassiny]

It doesn't really make sense to compare a 350T sail boat with a super tanker, a comparable diesel boat produce 36g per ton per km(according to the same report), the "grain de sail II" aims to replace those, and the gains are huge.

[reliablereason]

Well that comparision is what we were doing here.

There are market niches for many things that target things that are impractical for various reasons. There is nothing wrong with that.