About the SA Blog Network



Opinion, arguments & analyses from the editors of Scientific American
Observations HomeAboutContact

Solar-Powered Catamaran Circumnavigates Earth

The views expressed are those of the author and are not necessarily those of Scientific American.

Email   PrintPrint

PlanetSolar catamaran

Tûranor PlanetSolar ©

This Friday, May 4, a vessel named Tûranor PlanetSolar will become the first totally solar-powered boat to circumnavigate the Earth. The broad, V-shape catamaran left Monaco on September 27, 2010, traveled west on a mostly equatorial route, and will return to the Monaco Yacht Club 584 days later. Now crossing the northern Mediterranean Sea from Corsica toward France, Tûranor will have covered 53,000 kilometers, roughly 28,600 nautical miles.

The carbon-fiber boat, 31 meters long and 15 meters wide, has a flat deck that is plastered with solar panels made by SunPower. Flaps can fold out to expose additional panels, creating a total solar area of 537 square meters (5,700 square feet). The panels, which average 18.8 percent efficiency—among the highest for commercial products—charge six banks of lithium-ion batteries that can generate up to 93.5 kilowatts of power (about 127 horsepower) and keep the catamaran going for three days with no sun. Top speed: 27.3 kilometers per hour (17 mph, 15 knots). The hull and outriggers are designed to minimize air and water resistance.


The 38,000 silicon solar cells power the boat’s motor, water systems, lights—everything except the small propane cooking stove. The six-man crew that crossed the Atlantic Ocean from Monaco to Miami was subsequently reduced to four people to demonstrate “that it is not necessary to have a large crew to operate these technologies,” says Raphaël Domjan, an independent Swiss engineer who founded the project, designed the boat and serves as its skipper. He and his team derived the name Tûranor, meaning “the power of the sun,” from J.R.R. Tolkien’s novel The Lord of the Rings.

Domjan, 39, posts a daily log on the ship’s multimedia Web site. His April 30 entry conveys a mix of excitement and melancholy: “I realize that all the details surrounding our adventure were actually the engine of our life for the last 18 months. It is an awkward feeling to think that in a few days, all these little things that had become our life will disappear forever. When we left Monaco in September 2010, I was looking forward to seeing my mountains again, but…today, I realized…that I will be missing this feeling I have when sailing off, once I will be back to my life on the ground.” His last post will be May 7, after a weekend of dockside festivities at the Monaco Yacht Club.

Armchair adventurers can follow the final two days of the crew’s journey through frequent updates on Facebook and Twitter; Tûranor is scheduled to arrive in Monaco on Friday at 2 p.m. local time (8 a.m. EDT). The Web site also has lots of data about the boat, profiles the scientific team and details the catamaran’s current position and the course it took around the world.

Less-smitten pragmatists may wonder why Domjan built the $24 million vessel and spent millions more dollars to conduct the 18-month journey. Domjan says the planet “deserves a better, brighter and less polluted future.” The project, he says, “will help to motivate engineers and scientists to develop innovative technologies, inspire people around the world and show that the impossible can become possible.”

Boat designer and project leader Raphaël Domjan (left) in the cockpit with Philippines vice president during passage in July 2011. ©

Mark Fischetti About the Author: Mark Fischetti is a senior editor at Scientific American who covers energy, environment and sustainability issues. Follow on Twitter @markfischetti.

The views expressed are those of the author and are not necessarily those of Scientific American.

Rights & Permissions

Comments 13 Comments

Add Comment
  1. 1. Michael Moyer 2:27 pm 05/2/2012

    “Traveled on a mostly equatorial route”—does that mean it went through the Panama Canal, or did they brave Tierra del Fuego?

    Link to this
  2. 2. mfischetti 2:35 pm 05/2/2012

    Panama Canal. Probably would have added another six months to go around South America.

    Link to this
  3. 3. Rock LeBateau 4:28 pm 05/2/2012

    So let me get this right, It takes 38,000 solar cells, 6 men, nearly 2 years and 24 million bucks to get a boat round the world. But in 2005 it took 71 days 14 hours 18 minutes and 33 seconds for a tiny little Englishwoman Ellen MacArthur to sail her boat round the world. Her boat was solar powered too using wind as the energy transfer mechanism. Oh, and she went the hard way round – Cape of Good Hope, Roaring Forties, South of Australia, Cape Horn and back. I suppose it must be progress.

    Link to this
  4. 4. none12345 4:36 pm 05/2/2012

    First solar powered ship to circumnavigate the globe was almost 500 years ago….

    Wind is generated by solar power, every sail boat is solar powered.

    Link to this
  5. 5. geojellyroll 9:30 pm 05/2/2012

    About 25% of input costs on projects are produce materials…engineers driving to work…lights in offices, deliveries, equipment etc.

    So 6 million or so in energy construction costs…does not include a 25% of other operating costs…lets’s call it an even 8 million all inclusive for energy.

    …8 million bucks to circumnavigate the Earth in a small vessel that has no significant capacity??!!!!!

    Link to this
  6. 6. calsan 10:37 pm 05/2/2012

    Looks like a trimaran to me. Not a catamaran.

    Link to this
  7. 7. jtdwyer 1:17 am 05/3/2012

    Beware the gull & albatross over the ‘poop’ deck!

    Link to this
  8. 8. gmperkins 4:05 pm 05/3/2012

    That is impressive. I hope he has some people with him that can describe the engineering aspects of what worked well and what needs improving. The only way solar and other alternative energies will take off is with solid infrastructure and good engineering.

    Link to this
  9. 9. HubertB 5:59 pm 05/3/2012

    If I were out in the middle of the ocean in a solar powered boat, I would want it to work without depending on any infrastructure.

    Link to this
  10. 10. jerryd 7:59 pm 05/3/2012

    I design, build multihulls and this boat is a scam. They could have done the same thing probably faster in 40-50′ rather than a 100′ monster. It’s overweight and too high drag, wetted surface, because of how it is designed.

    As far as crew it doesn’t really need any crew if they want.

    Had I designed it it would be a 45′ trimaran which would have 15% of the drag, cost and weight.

    Link to this
  11. 11. Dr. Strangelove 10:09 pm 05/3/2012

    A solar-powered boat is totally ridiculous. Pound for pound, a sail boat is 50 times more powerful. Planet Solar weighs 95 tons and produces 93.5 kW. That’s 0.98 kW/ton. A sail boat with the same sail area as the solar panels (537 sq.m.) will weigh around 20 tons and produce over 1,000 kW of wind power. That’s 50 kW/ton.

    Planet Solar circumnavigation was 28,600 nautical miles in 584 days. That’s an average speed of 2 knots. The circumnavigation record for a sail boat is 28,964 nautical miles in 45 days. That’s an average speed of 26 knots.

    And a sail boat doesn’t cost $24 million. Planet Solar is an expensive toy that performs very poorly compared to sail boats.

    Link to this
  12. 12. Dr. Strangelove 10:47 pm 05/3/2012

    BTW the engineers of PlanetSolar are proud of its top speed of 15 knots. Guys, smaller and cheaper sail boats can go over 35 knots or 3 times faster.

    Link to this
  13. 13. Dr. Strangelove 10:50 pm 05/3/2012

    Correction: Make that 45 knots. Yes, trimarans can go that fast.

    Link to this

Add a Comment
You must sign in or register as a member to submit a comment.

More from Scientific American

Email this Article