On average, each 10-horsepower motor only has 6 kW of electricity at its disposal, roughly the same as the Wright Brothers had on their first flight. Despite the plane's size, the pilot only has 1.3 cubic meters of space in the cockpit that can go from freezing to sweltering over the course of a flight.

Night flights
"The project was, of course, about building an aircraft, but it was more about saving energy," said Borschberg, speaking last week at the Swiss Embassy in Washington, D.C. "The power we can use is the power of a scooter."

The dynamics of flight make all these compromises necessary, but the HB-SIA has already posted some impressive results. The Solar Impulse team set a flight record with 26 hours, 10 minutes, 19 seconds aloft, spanning day and night. Next summer, they plan to fly from San Francisco to New York City with a stopover in Washington, D.C.

The team also wants to build a bigger plane that can fly for five to six days at a time. With this aircraft, Borschberg and Piccard will attempt to fly around the world in 2015, taking turns at the controls.

The PlanetSolar and Solar Impulse teams acknowledge that these feats do not translate directly into new paradigms and it may be some time before photovoltaic panels are commonly seen on wings and decks. "We do not believe that you can just put solar cells on a boat and it will work," de Puechredon said. However, with current technologies and these proofs of concept, "we don't need to wait another 15 years to fly around the world."

Piccard echoed this sentiment. "What is important is to show that we can go from the dream to reality," he said. He noted that the first gliders were made from cloth and wood, technology that was available to the Babylonians; all that was lacking was the will to make one. For that reason, when faced with the possibility of large-scale renewable transportation, Piccard said, "it would be crazy to answer 'yes' and stupid to answer 'no.'"

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

8 Comments

1. 1. Crasher 05:49 PM 12/19/12

   Perhaps a small step in the right direction.

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2. 2. Dr. Strangelove 09:39 PM 12/20/12

   The solar boat is an expensive, inefficient toy. The sail boat is more energy efficient and practical. Solar panels can capture around 200 watts per sq. m. of energy from the sun. A sail can capture over 1,000 watts per sq. m. of energy from the wind. Hence, a sail produces 5 times more power and it's lighter and cheaper than solar panels.
   
   That's why the circumnavigation speed of the solar boat is 5 knots while the sail boat record is over 19 knots.

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3. 3. tcm13 08:08 PM 12/21/12

   @Dr. Strangelove
   What you say may be true, but I have yet to see a sail boat save wind power for a windless day.

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4. 4. greenhome123 11:27 PM 12/21/12

   I agree with previous comments and believe that wind is probably the most efficient way to move a boat. Nevertheless, I think the most practical commercial ship design would be one that incorporates diesel or biofuel engine, with a kiteship, kiteboarder style kite/sail, and solar panels that can provide electricity for passengers and so forth on the ship during the day to lighten load on diesel engine so boat get better mpg. Also, for cruise ships I believe they should start saving all of the foods waste from the cruise, which i'm sure there is a lot, and turning it into a biofuel via pyrolysis/gasification or also could use anaerobic digestion method, and this biofuel could be used to power cruise boat on current or future cruises.

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5. 5. greenhome123 11:36 PM 12/21/12

   I agree with previous comments and believe that wind is probably the most efficient way to move a boat. Nevertheless, I think the most practical commercial ship design would be one that incorporates diesel or biofuel engine, with a kiteship, kiteboarder style kite/sail, and solar panels that can provide electricity for passengers and so forth on the ship during the day to lighten load on diesel engine so boat get better mpg. Also, for cruise ships I believe they should start saving all of the foods waste from the cruise, which i'm sure there is a lot, and turning it into a biofuel via pyrolysis/gasification or also could use anaerobic digestion method, and this biofuel could be used to power cruise boat on current or future cruises.

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6. 6. Dr. Strangelove in reply to tcm13 04:25 AM 12/22/12

   Obviously you're not a sailor. The sea is never windless but it is sunless at least 12 hours everyday. Experienced sailors can sail with the lightest breeze.

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7. 7. Dr. Strangelove in reply to greenhome123 04:36 AM 12/22/12

   Yes, sail and engine is a good combination. If you want to be environment friendly, I will go for the classic steam engine powered by firewood.

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8. 8. Donzzz 09:46 PM 12/26/12

   Dr. Strangelove - did you ever hear of the doldrums?

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