The world's biggest solar-powered boat was unveiled yesterday in Germany. Pictured is the model of the boat.

The boat is 30 metres long (98 foot) and has 500 square metres of solar panels on its top, the hull.

The boat, called PlanetSolar, can carry up to 50 passengers and can travel at a speed of 17 miles per hour, or 15 knots.

Plans are now being made to launch a round-the-world trip in the boat next year.