In time the entire deck, cabin and hull sides above the waterline will be collecting power, as will wind generators at anchor. Some types will be vertical deploying from the mainmast once the sail is furled round or inside the boom. We may see solar cells built into the sails themselves. With solid sails proven in the little Americas Cup, these are bound to gain popularity, especially doubling as sites for solar cells. Storage batteries are not such a problem as sailboats require the ballast anyway.
Gel batteries are stable at any angle and immersed.
Propulsion units are OK already, they just need the acceptance required to see them marketed for a reasonable price. A Laurent Giles customer has boldly commissioned this venerable firm to redesign a classic13ton 43ft cruiser for electric auxiliary and a modern build. The projected cost of 380 thousand English pounds is not a testament to its futility, merely its uniqueness. The cost per unit of electric propulsion is already less than fossil fuels. The one remaining barrier is range, longevity of supply.