It may not have shattered any speed records, but the Tûranor PlanetSolar catamaran has become the first boat to circumnavigate the globe using only solar power: no sails, no fuel, no exhaust. Designed and built by an international team of naval architects and engineers, the lightweight-carbon-fiber vessel is covered with 38,000 solar cells that drive a 30-hp electric motor. After celebrating the completion of the 584-day voyage in Monaco, German investor Immo Ströher said he was considering putting the 115-footer up for sale. “We are open for ideas and in talks with interested parties,” he said. The only problem is, what you’d save in fuel, you’d probably spend in Windex!