An international team of scientists, engineers and boat builders from Germany and Switzerland has developed the world’s largest solar powered boat designed to circumnavigate the world. The PlanetSolar multihull vessel, built by Knierim Yatch Club, was unveiled on February 25, 2010 at the HDW Shipyard in Kiel, Germany.
PlanetSolar includes high efficiency photovoltaic technology from SunPower Corporation of San Jose, California. About 38,000 cells cover almost 500 square meters of the upper deck in this 6-meter high, 31-meter long by 15-meter wide catamaran (its surface increases to 35-meters in length and 23-meters in width with its retractile flaps extended). The cells are integrated to its surface. The next generation cells used have “efficiency of at least 22 percent” according to SunPower delivering 103.4kW (138.6HP).
Drivetek AG has been responsible for the project management of the power system including energy management and propulsion; i.e., drive unit including inverter, motors and the Maximum Power Point Tracker (MMPT). The MMPT specifically designed for maritime applications by Drivetek optimizes the amount of solar power received from the photovoltaic panels, according to Thomas Schafroth, project manager of the company. The MMPT 7500 is the brain of the PV solar system. It controls the amount of energy flow between generation, propulsion and storage to obtain over 99.3% efficiency from one third of the maximum net power under dynamic changes in irradiation and solar modules alignment, and particularly under weak loads. The electricity generated by the solar cells is stored in 700 GAIA Lithium ion batteries yielding enough storage to navigate during three days with cloudy conditions. The special Li-ion batteries used by PlanetSolar are the world’s largest round battery cells. Together, they provide more than 1MW-hr of capacity equivalent to 130,000 laptop cells (a laptop battery pack usually carries several cells of about 10Wh each), according to the manufacturer. The three-hull (one central hull with two floats) hydrodynamically designed craft has four electric engines that drive two propellers delivering 20kW (26.8HP) each of clean propulsion to move its 60-ton weight at a maximum speed of 14 knots. The propulsion system is fail-safe with parallel system architecture.
The planned voyage around the world will start next year from Europe. The ship will follow a west route that will maximize the solar energy collected using for navigational support a meteorological service from France. It is expected to reach an average speed of 8 knots covering approximately 40,000km in about 4 months. The craft will carry a crew of two during its world tour and will be able to host up to 50 visitors at each of its planned stops. PlanetSolar will be launched in April 2010 to start testing of all its systems while traveling to the Mediterranean. The world tour itinerary is set to start in April 2011. It includes Miami as a possible alternative stopover. Other ports under consideration (subject to change) include Monaco, Marseille, New York, Acapulco, San Francisco, Cairns and Darwin in Australia, Shanghai, Hong Kong, Singapore, Abu Dhabi, and Dubai. The first solar powered boat to cross the Altantic was the Swiss, 15 meters Solar21 catamaran. It made the journey between the Canary Islands and Martinique in 29 days at a top speed of 9 knots reaching Miami on March 29, 2007.
References:
http://www.examiner.com
http://www.germany.info
http://planetsolar.org
http://us.sunpowercorp.com