https://www.reddit.com/r/kites/comments/14viyvw/kite_power_project_what_kite_should_i_use/
I noticed a link from clicking on this story, a yacht pulled by a kite:
SILENT 60 - Kite Sail System Premiere - YouTube
The yacht is called a
Silent 60
and there are other sizes besides the â60â in production.
They make a great show of explaining how they designed it from a fresh sheet around the electric motors, batteries, and solar panels, and how the motors are only the size of a couple of shoeboxes, easily hidden beneath the floorboards.
The manufacturerâs own publicity does not seem to include the kite, in fact they explain how much better solar is than wind for a boat
Then, after watching quite a lot of video footage, about how perfect it all is, they feel that they must divulge a hidden secret:
At 15 minutes into this video, they reveal the 220 Horsepower, diesel-powered, Volvo Penta D3-220 engine, calling it a âbackup generatorâ - you know, just in case you want to go somewhere and it is getting dark, or cloudy, or whatever⌠They say it would be irresponsible not to have it. 
Video:
The 100% Solar Powered Sun Ship That NEVER Needs Charging! - YouTube
Hereâs a video of a catamaran 100% pulled by a kite from 3 years ago:
Project KITE BOAT - 25 Knots - Part TWO - YouTube
The principle is explained on:
See also
Powering Container Ships with Food Scraps:
What about cruise ships with onboard conversion of food scraps to methanol?
Meanwhile, can the engines run on regular bunker fuel, or are they locked in to methanol?
The article says Maersk wants to convert a quarter of their container ships to methanol.