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Solar success on trans-Atlantic passage

PlanetSolar receives a warm welcome in Miami, its first stopover on the way to a circumnavigation

It works. After 62 days, 34 minutes of voyaging under power of the sun alone, the 100-foot Turanor PlanetSolar glided silently down Government Cut to the face dock at the Miami Beach Marina, completing the first 6,300 miles of an attempt to become the first boat to ever make a solar-powered circumnavigation.

The cat crossed the Atlantic in record time for a solar-powered vessel.

"It's very nice to see that our five years of study and work was a good job and our idea is working," says Raphael Domjan, the project's Swiss founder and co-skipper.

He found the leg across the Atlantic from Monaco to the Azores and St. Maarten and the Nov. 28 arrival in Miami "very exciting."

  • Exciting because the boat worked - the solar-power hardware, the software that factors in weather forecasts to set courses and speeds and maximize PlanetSolar's exposure to the sun, and the twin wave-piercing hulls.
  • Exciting because he and his five crew still are learning how to keep PlanetSolar's 800 lithium polymer battery cells - 11.7 tons of them - powered up to move this 100-ton behemoth at the average 7 to 8 knots for which they planned.
  • Exciting because PlanetSolar received a warm welcome at its first major stopover, in Miami - hundreds of visitors and major media coverage.
  • Exciting because the solar boat had to dive way south during the crossing to give Hurricane Tomas a wide berth and still the crew encountered 9-foot seas and three days of cloudy skies that slowed them.

Still, PlanetSolar crossed from Las Palmas in the Canary Islands to St. Maarten in 26 days - three days faster than the 46-foot solar-powered catamaran Sun21's record-setting 2007 trans-Atlantic crossing from Las Palmas to Martinique. Both crossings were about 3,100 miles.

Domjan says PlanetSolar's speed averaged 5 to 6 knots, slower than he had hoped, but the sun in the Northern Hemisphere in the fall is not at its most intense. He expects to speed up in the Pacific, where PlanetSolar will girdle the equator and benefit from more intense sunlight and trade winds. His goal: a 140-day, 25,000-mile east-to-west circumnavigation via the Panama and Suez canals.

"The idea of this project is to show what you can do with energy from the sun with today's technology," Domjan says.

He says most of that technology, including more than 5,000 square feet of solar panels arrayed on a large, flat deck and on wings that fold out to extend the deck at the sides and stern, is off the shelf. Even the computerized navigation and routing system that factors in weather and the vessel's solar needs is a customized version of standard navigation and weather software, according to Domjan.

"After we finish, that software will be on the market," he says. "Anyone can buy it for cheap."

Domjan estimates that there are 200 solar-powered boats in the world today. He expects that number to grow to more than 1,000 by the end of 2011, in part because PlanetSolar is demonstrating that solar-powered ocean cruising is possible and because its solar-routing software will be available for boats large and small.

"It is the future," he says. The marine community just needs to know that the technology for solar-powered voyaging exists and that it works.

"I'm very happy with the boat," says Immo Stroeher, the $10 million solar yacht's owner and chief investor. "This project has come from dream to reality."

A German investor in clean technologies through his Swiss company, Rivendell Holding AG, Stroeher says that when Domjan presented his plan for PlanetSolar five years ago "it made a click and I was hooked." The only problem: Stroeher gets seasick, so he'll probably only use the boat when it transits the Panama Canal.

Stroeher, who has been in the solar business for 20 years, says a factory of his in Germany made the modules in which PlanetSolar's 38,000 solar cells are housed. Sunpower, of San Jose, Calif., supplied the high-efficiency cells.

The solar panels deliver 94 kW on a bright, sunny day, about five times the 20 kW of electricity that the motors need to push the boat at an economical cruising speed of 7.5 knots. The batteries store 1.2 mW hours, enough to power the boat for three days - or about 625 miles - without any sun at all.

The vessel has two electric motors - one 20 kW, the other 40 - in each float. Each of the boat's propellers is more than 6 feet in diameter. "They've got a lot of push," says the boat's master, Frenchman Patrick Marchesseau.

He says the boat rode the 9-foot seas from Hurricane Tomas well. "She's quite large, has two hulls and good stability," Marchesseau says. "Waves were smashing over the deck from the back. It was no big deal."

Finnish sailor Mikaela von Koskull crewed twice on racing sailboats in the Whitbread Round the World Race - now the Volvo Ocean Race - and for Steve Fossett on his record-setting 105-foot sailing catamaran PlayStation, which revs up to 44 knots, von Koskull says. PlanetSolar "is slower, of course," she says. "We go 4 to 8 knots. It's a different concept but very, very interesting."

PlanetSolar slipped away quietly from Miami on Nov. 30, bound for Cancun, Mexico, then likely San Francisco, Sydney, Singapore, Abu Dhabi and back to Monaco.

The crew of the solar boat see themselves as neither racers nor cruisers.

"This is more like an adventure expedition," von Koskull says.

This article originally appeared in the February 2011 issue.