Planet Solar - The World's Largest Solar Boat

Key Data

Entry into Service

2011

Crew

4

Displacement

85t

Owner

PlanetSolar SA

Builder

KNIERIM Yachtbau GmbH

Designer

LOMOcean Design

Motors

4 x Electrical permanent magnet synchronous motors

The PlanetSolar is a solar-powered vessel built by Knierim Yachtbau, in Kiel, Germany for Switzerland-based PlanetSolar. It is the biggest solar boat ever built. The solar powered craft is topped by a large array of photovoltaic panels. The boat has been designed to circumnavigate the world. It will become the first multi-hull vessel to sail around the world using solar energy. The voyage is scheduled to begin in 2011. A distance of more than 50,000km will be covered in 160 days at an average speed of 8kt. The boat will set sail from Marseilles and will cross the Atlantic Ocean, the Panama Canal, the Pacific Ocean, the Indian Ocean and the Suez Canal to join the Mediterranean. PlanetSolar specifications PlanetSolar was christened and launched in March 2010. The solar boat made its first voyage off Kiel in April 2010. It will be stationed in the waters of the Baltic Sea to complete a test phase. The 31m long PlanetSolar has a beam of 15m (23m with flaps) and draft of 1.55m. The height above waterline is 6.10m. The deadweight of the boat is 85 tonnes. It can sail at a maximum speed of 14 knots. The boat can accommodate four crew and up to 50 personnel on its world voyage. The solar generator can produce peak power of 93.5kW. The efficiency is estimated at 18.8%. Lithium Ion (NCA) batteries have the voltage of 388V and capacity of 2910Ah (485Ah / cell). PlanetSolar design The solar-powered boat was designed by Auckland-based naval architecture and yacht design company LOMOcean Design. The design phase included the successful comprehensive test programme involving towing tank tests in calm water and waves. The ship design incorporates a main hull featuring two hydrodynamic floats. The top of the boat is surfaced with 127 photovoltaic modules covering 537m². The power generated by the modules is stored in Lithium Ion (NCA) batteries. The 648 cells installed in the boat weigh about 11t. The board battery banks have an efficiency of over 95% and deliver electricity to the electric motors in each demi-hull. Construction Swiss Rivendell Holding funded the construction of the boat amounting to €12.5m. The construction began in January 2009 at the shipyard Knierim Yachtbau in Kiel and took 14 months to complete. The project is supported by the French Ministry of Ecology, Energy, Sustainable Development and Land Settlement.Around 100 personnel were involved in the shipbuilding. The boat is made of carbon-fibre epoxy sandwich materials. About 20.6t of steel, 11.5t of sandwich core and 23t of Epoxy Resin and Hardener are used in the construction. The photovoltaic modules are supplied by the Immo Ströher. Autodesk provided the technology to create 2D and 3D plans of the boat. Performance The solar-powered catamaran demonstrated highest efficiency during the towing tank tests conducted at the Australian Maritime College in calm water and waves. The wind tunnel tests also proved successful. The displacement during the circumnavigation will be 65t, further it will be increased to a displacement of 85t to serve as a luxury yacht. Propulsion The PlanetSolar is powered by four high-efficiency electrical permanent magnet synchronous motors driving five-bladed carbon fibre propellers through two drive shafts. Four motors develop a total power output of up to 176kW (239bhp), of which about 20kW per hour is consumed at cruising speed. The backup power is utilised at night and during rains. The advanced lithium-ion batteries can store up to 1.3MW of solar energy under deck. The boat is equipped with a rudderless steering system. Each propeller supplied by AIR has a diameter of 2m and rotates at a maximum speed of 160rpm.