The world's largest solar boat has been unveiled. Called PlanetSolar, which is a 31m long and 15m wide white catamaran, has been designed to reach a top speed of around 15 knots, and can hold up to 50 passengers. Power entirely by up to 500 square metres of photovoltaic solar panels. The boat’s 38,000 photovoltaic cells have been provided by SunPower, their new cells have an efficiency of at least 22%. The boat has been designed for a global circumnavigation planned for 2011. The 60 ton catamaran has been built at the cost of 18 million euro(about $24.4 million) at the Knierim Yacht Club in Kiel in northern Germany.