1. Caribbean Princess generates smoke while sitting alongside the pier last September.
While cruise ships do not need their main propulsion engines while docked, they still have huge power demands for on board services (called "hotel load"), and burn heavy fuel or diesel to generate it.
While going to shore power may eliminate scenes like that above, it will certainly add to Nova Scotia's power generation needs. Perhaps fortunately the local power plant burns natural gas, but there is still a lot of coal generated power in Nova Scotia. Since all power essentially goes onto the same grid, if there is a demand spike that cannot be met by the local gas plant, some of the new shore power may well come from coal fired plants. Plans for delivering hydro-electric power to Nova Scotia from Labrador are still in the very early stages, and it will be many years before we are weened from coal.
Of course cruise ships only spend part of the time in port - they spend as least as much or more time sailing through our coastal waters, where they do burn heavy fuel. Cruise lines are complaining about switching to low sulphur fuels, but that should be part of the equation here too.