These silent luxury yachts run on solar energy
The newest version of a yacht that runs completely on solar energy was unveiled at the  2019 Cannes Yachting Festival, and it is has an unlimited range and doesn’t emit noise or fumes. The Silent 55 catamaran is powered by the sun, and it runs with minimal vibration and is virtually maintenance-free. It has been manufactured by an Austrian company, Silent Yachts, founded by CEO Michael Köhler and his wife Heike. They were inspired by their own experience of boat-ownership, as they were unhappy when the propulsion systems were fuel-based.  They built the first Silent Yacht’s hull ten years ago and their newest 56-foot yacht has structural improvements, a completely revised drive-train with significantly more battery power, and e-motors that are twice as powerful as the 2018 model. It runs on solar-powered propulsion thanks to 30 high-efficiency solar panels and it glides along and doesn’t emit noise or fumes.  The Silent 55 is able to cruise all night thanks to its maximum power point tracking solar charge regulators and lithium batteries. The generator can be used on the rare occasion that the batteries require charging out at sea. Using solar power means that the operation is quiet as there are no vibrations of permanently running generators to endure, and it is cost-effective to run because it doesn’t use fuel.  There are five different layouts to choose from, and they range from three to six staterooms that each offer double or twin berths.   Source: https://www.lonelyplanet.com/articles/solar-powered-catamaran