Looking to sailing yachts we at Leisure-Sailing LTD strongly believe that the answer is clearly: YES!
A sailing yacht needs the engines for docking maneuvers or in low wind situations. That means the operation period of the engines is highly reduced compared to non sailing yachts. A system that operates up to 2 hours on batteries only is sufficient when propulsing a sailing vessel.
During sailing the batteries might be recharged using the propellers. During daylight recharging batteries may be done using solar power. Windpower might be used as well to generate energy for the charging of the batteries. As a backupsystem there should be a (diesel) generator on board in order to bridge for any kind of energy shortage.
Combining the possilities provides for an unlimited sailing range. Maverick Yachts offers solutions for hybrid systems on their custom catamarans (440) and will provide similar posibillities for the upcomming projects.
Do you want to know more: info@Leisure-Sailing.net