July 18, 2015

Several photographs for this post originate from The Daily  This is a publication from the UK.

There are several stories each year that really excite our imagination. One is the Solar Impulse and the travels that craft has accomplished over the past few months.  Even though the news releases are recent, the actual engineering and fabrication took years to accomplish.



Someone once said, “If it looks like it will fly—it will fly”.  I’m not too sure that can be deduced from the configuration above.  The next digital will give you a much better picture as to the overall structure.



Solar Impulse 2 is powered by 17,000 solar cells and on-board rechargeable lithium batteries, allowing it to fly through the night. Its wingspan is longer than a jumbo jet but its light construction keeps its weight to about as much as a car.  The Solar Impulse 2 relies on getting enough solar power during the day to survive the night. It is also extremely light – about the weight of a car – and yet as wide as a passenger jet. Both of these combined facts make it extremely susceptible to the weather. In high winds or turbulent circumstances it can struggle to stay aloft at the altitudes necessary to gather sunlight.

Its maximum altitude is 27,900ft (8,500m), before dropping to 3,280ft (1,000m).  This allows the pilot is able to take short 20-minute catnaps. One huge issue with the aircraft is pilot fatigue.  Solar Impulse 2 and its pilots André Borschberg and Betrand Piccard set off from Abu Dhabi in March with the hope of returning within five or six months. It was forced to make an unscheduled stop in Nagoya in Japan after bad weather stopped it taking off on its Pacific leg, but it successfully touched down in Hawaii on 3 July after 118 hours.

Bertrand Piccard initiated the Solar Impulse project in November 2003 after undertaking a feasibility study in partnership with the Ecole Polytechnique Fédérale de Lausanne. By 2009, he had assembled a multi-disciplinary team of 50 engineers and technical specialists from six countries, assisted by about 100 outside advisers and 80 technological partners.  The project is financed by a number of private companies and individuals, as well as receiving around CHF 6 million (US$6.4 million) in funding from the Swiss government.

The first company to officially support the project was Semper Gestion, after its co-founder Eric Freymond was convinced of the future success of Piccard.  The project’s primary partners are Omega SASolvaySchindler and ABB.  Other partners and supporters of the project include Bayer MaterialScienceAltranSwisscomSwiss Re (Corporate Solutions),ClarinsToyotaBKW FMB Energie and Symphony Technology Group. The EPFL, the European Space Agency (ESA) and Dassault have provided additional technical expertise, while SunPower provided the aircraft’s photovoltaic cells. In October 2013, Solar Impulse announced that Peter Diamandis, founder of the X Prize Foundation, had become a supporter of the project after meeting with Solar Impulse officials during Google‘s 2013 Zeitgeist event.


  • Crew:1
  • Length:85 m (71.7 ft)
  • Wingspan:4 m (208 ft)
  • Height:40 m (21.0 ft)
  • Wing area:11,628 photovoltaic cells rated at 45 kW peak: 200 m2 (2,200 sq ft)
  • Aspect ratio:7
  • Loaded weight:1,600 kg (3,500 lb)
  • takeoff weight:2,000 kg (4,400 lb)
  • Powerplant:4 × electric motors, 4 x 21 kWh lithium-ion batteries (450 kg), providing 7.5 kW (10 HP) each
  • Propeller diameter:5 m at 200 to 400 rpm (11 ft)
  • Take-off speed:35 kilometers per hour (22 mph)




If we look at the timeline, we see the following:

  • 2003: Feasibility study at the École Polytechnique Fédérale de Lausanne
  • 2004–2005: Development of the concept
  • 2006: Simulation of long-haul flights
  • 2006–09: Construction of first prototype (HB-SIA; Solar Impulse 1)
  • 2009: First flight of Solar Impulse 1
  • 2009–11: Manned test flights
  • 2011–12: Further test flights through Europe and North Africa
  • 2011–13: Construction of second prototype (HB-SIB; Solar Impulse 2)
  • 2013: Continental flight across the US by Solar Impulse 1 (Mission Across America)
  • 2014: First flight of Solar Impulse 2
  • 2015: Circumnavigation by Solar Impulse 2, conducted in twelve stages over five months


I think the route is extremely difficult.  Only the very best calculations minimizing the risks involved would allow for such an adventure.  Please keep in mind, this legs were all accomplished on solar energy—solar energy alone.



I think this is an amazing engineering feat—absolutely amazing. I’m not sure at all if it proves solar energy is a viable alternative for air travel, especially when you consider modern-day air travel.  Think of all the critical systems on a modern airliner.  Many of those systems have redundentcy that allows for failure with almost instantaneous backup to eliminate cessation of operation.  I can’t imagine this level of development if we are considering solar power for commercial air travel.  I think this is a very bold engineering attempt and one that will probably, in the long run, provide other uses for solar energy.


What do you think?

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: