Around the world in a solar yacht

The Toranor PlanetSolar is seeking to become the first fully solar-powered vessel to circumnavigate the world. The craft, which began its journey in September 2010 when it departed Monaco, recently arrived at Brisbane, Australia, where this picture was taken.

Measuring close to 102 feet in length and 50 feet in width, the Turanor PlanetSolar has made stops at the Gal

The Turanor PlanetSolar's multi-hull catamaran features a solar photovoltaic surface area of over 537 square meters, housing 38,000 high-efficiency solar cells. The company says that makes it the biggest solar-powered ship in the world. The vessel's skipper recently told CNN that battery power has never fallen below the 20%. level. "We are very happy with the performance of the boat," he said. "Although it is going a little bit slower then expected in good conditions, it is much better with difficult weather."

German entrepreneur Immo Str

With a four-man crew, the yacht will attempt to cover about 27,000 nautical miles in its bid to prove that current renewable energy technologies are reliable and effective. With its arrival in Australia in late May, it has now logged over 15.000 nautical miles.

So far, the Turanor PlanetSolar's solar system, batteries and engines have held up to the strain. But in March, the crew was forced to return to Bora Bora because of mechanical problems that affected the propeller blades' steering system.