There is not enough surface area for the amount of solar that would required to power the ship, let alone, charge batteries
Batteries would create significant weight additions
Water / turbine power …. You need a source to propel you through the water in order to turn the water turbine, create a net negative
Like the sailors of yore, kites are the most logical addition. That’s a relative term. With the price of diesel, im sure if it would’ve saved money it would have been done by now.
Capitalism really is an incredible system of incentives.