The case for solar energy as a viable power source for marine propulsion was well made when news came just a few days ago that the world’s largest vessel entirely powered by solar energy, PlanetSolar, had completed its trans-world odyssey, returning to Hercule Harbour, Monaco, where it had set out for the world circumnavigation attempt. An entry in the ship’s log the day before final arrival recorded the highest day’s energy yield –  661 kW hours –  from the 537 square meters of photovoltaic solar panels , the vessel’s sole source of energy,  since the voyage began on 27, September 2010. PlanetSolar in Hamburg: Photo credit Wiki CCL Dr. Karl-Heinz Hochhaus Constructed of weight-saving carbon fibre, the 31 m (101.7 ft) long PlanetSolar  (Swiss registered as Tûranor PlanetSolar or ‘Power of the Sun’ in Tolkien’s fiction) was launched in Spring 2010 from the Knierim Yachtbau shipyard in Kiel, Germany. Con... [More]