Nearly 500 years ago, Ferdinand Magellan led the first expedition to sail around the world. With wind and sails, the journey was certainly a green one.

    Now a Swiss engineer wants to match the feat — with a catamaran called “Planet Solar,” powered entirely on the sun’s energy.

    It’s a clean-tech adventure designed by Raphael Domjan to promote solar power, energy efficiency and sustainable mobility. Domjan calls it “the path towards a lasting world.”

    “(I) want to show that we can change, that solutions exist and that it isn’t too late,” Domjan writes on his Web site. “Future generations are looking to us; our choices will mark the future of humanity.”

    Domjan — who has been an ambulance driver, mountain guide and rescue specialist — will skipper the boat with Gerard d’Aboville, who was the first person to row across the Atlantic Ocean.

    Called “Planet Solar,” the futuristic-looking no-sails catamaran is being built in Germany. Domjan and d’Aboville will launch the round-the-world attempt in 2011.

    Domjan told CNN that he hopes the $11.5 million project will prove that boats can travel at high speed without emitting any carbon dioxide.

    The boat’s deck will be covered in 470 square meters of solar panels. Its skippers hope to average a speed of eight knots but can push the vessel to 14 knots (15 km/hour and 25 km/hour, respectively).

    The boat, in photos available online, appears to have two propellers at its stern for propulsion.

    To take advantage of the most sunlight possible, the tentative route is largely around the equator. In case of bad weather, batteries on board will be able to store solar energy to power the boat for three days, according to CNN.

    But if cloudy weather blocks the sun for longer, the boat will have trouble. Do you have any thoughts on a green back-up plan for the ambitious sailors?

    (Writing and reporting by Laura Isensee)

    Photo Credit: A 3-dimensional model of the futuristic-looking boat. Courtesy of PlanetSolar.com