The toughest part of sailing a boat 37,286 miles around the world using only solar power turns out not to be, say, that the sun won’t shine, or that the machinery breaks down. It’s a more common problem associated with shipping these days: pirates.
Raphaël Domjan, a Swiss national, who has just returned to Monaco after a 19-month journey aboard the MS Tûranor PlanetSolar says by far the hairiest bit was crossing the Gulf of Aden, a notorious place for kidnapping and hijacking.
"It was one month with soldiers onboard, and a lot of stress," he says. "We were at 5 knots with the solar energy, and we were between Yemen and Somalia. In Yemen, with the soldiers and guns we had, we could have gone to jail. And in Somalia, we could be hostages, and eat rice for one year."
It’s more normal for ships crossing the stretch to go at 15 to 20 knots, to make it as quickly as possible. And Domjan says most boats that do it are a lot larger than the Tûranor, which is 115 feet long and 75 feet wide.
To get the best sunlight, the four-strong crew followed the equator as closely as possible. Leaving the Mediterranean, they went across the Atlantic to Miami, and then down through the Panama Canal, across the Pacific and the Indian Ocean, and eventually through the Suez Canal.
Domjan says the solar power worked almost perfectly, powering the boat and everything onboard except for a gas-powered cooker. He says the crew never feared it would run out of power, because even on dark days the panels could generate some power. "We had one whole week of bad weather, and we were able to manage," he says. Batteries provided three days of back-up power, if needed.
Domjan says the point of the expedition was to prove that solar power is "for today and not tomorrow," and that it’s possible to be "optimistic" about the future of energy, despite gloom about its cost, and the worsening threat of climate change.
"We know that climate change is a challenge for our civilization, but there are also opportunities, and we have to be optimistic," he says.
An important part of the voyage, as with other renewable energy expeditions, was to stop in different locations to show off the boat, and make the case for solar. In all, the boat stopped 28 times, including in Tangier, the Galápagos, Brisbane, and Abu Dhabi.
Domjan says the boat could have gone nonstop, but probably would have taken a different route round the world’s three main capes to do so.
Aside from becoming a world record holder, Domjan says he wants the world to know that solar power can be used in many different boats if inventors put their mind to designing them.
"We can use solar boats for diving boats and tourism. Not everywhere but in many places," he says.
"It’s very nice because you have no noise and no vibration. To see the wildlife and the dolphins, it’s much better than on a normal motor boat." You just need to avoid those pirates.