A seafaring band of scientists, engineers and yachtsmen with an obsession for Jules Verne and clean energy are building what they call the largest solar boat in the world, a $13 million catamaran they hope will take them around the world next year.

Construction is well underway on the 98-foot-long vessel, which will feature 5,059 square feet of photovoltaic cells. The project is being funded by Rivendell Holding AG, a Swiss firm that invests in renewable energy, simply to prove it can be done and the shipping industry can reduce its dependence on fossil fuel.

The team plans to circumnavigate the globe at the equator in 120 days at an average speed of 10 knots. Should they succeed, Planet Solar will set a maritime milestone. Solar electric pleasure boats have been tooling around lakes for awhile now, solar electric ferries are increasingly common and a solar electric catamaran called Sun 21 crossed the Atlantic in 29 days. But so far no one's made it around the world in a solar electric boat.

"Solar boats are a viable form of transportation for the future," Delia Collardi, a spokeswoman for the project, told Wired.com. "Our society is too dependent on fossil fuels, which are in limited supply and which are causing measurable negative effects on the earth's atmosphere. It's now time to demonstrate the potential that renewable energies have to offer in the area of mobility."

The project still has a long way to go - approximately 24,901.55 miles - but work on the solar cat's hulls is almost complete.

Planet Solar is being built at the Knierim Yacht Club in Kiel, Germany. The vessel, which is shaped something like an arrowhead, will be 98 feet long and 50 feet wide. That climbs to 114 feet and 82 feet when the solar panels are fully unfurled.

There aren't many details on the drivetrain, and Collardi says the batteries "have not been defined." A press kit says the boat will weigh 60 tons and feature 470 square meters - 5,059 square feet - of photovoltaic cells that offer 22 percent efficiency.

Collardi says the vessel will have enough power to carry skipper Raphael Domjan, the 37-year-old founder of Planet Solar, and navigator Gerard d'Aboville. Both men are accomplished sailors and adventurers who, according to a press release, "want to be the Phileas Fogg" of the 21st Century.

Fogg, of course, was the adventurous main character Around the World in Eighty Days, Jules Verne's novel about a man who travels by train, balloon, steamer and even elephants to circle the globe in record time and win a bet. Verne's great-grandson Jean Verne has signed on to the project, which organizers say represents "humanity's hope for a better future."

The route is still being worked out, but Planet Solar will set sail from Marseilles, France sometime next year and cross the Atlantic, then cut through the Panama Canal to cross the Pacific. From there she'll head south through the South China Sea to the Indian Ocean before crossing the Indian Ocean and Red Sea. Then it's through the Suez Canal and across the Mediterranean Sea and back home.

Ports of call are to be announced, but stops in New York, Shanghai, Singapore, Abu Dhabi and Monaco are among those being considered. Supporters and well-wishers will be welcomed aboard, and Collardi says 50 people can fit inside the catamaran for short jaunts.

Immo Stroher, founder and president of Rivendell Holding, has dibs on Solar Planet at the end of the journey.

Photos and renderings: Planet Solar.