There are no battery technologies which can power a cruise ship at the dock for several days at a reasonable cost and weight. The power density just isn't there, and won't be for many years.
Shore power works fine. It would be a lot simpler to just mandate it actually be used, and bar ships which don't use it from docking.
Shore power works fine. It would be a lot simpler to just mandate it actually be used, and bar ships which don't use it from docking.