Solar Impulse 2 Preps for 1st Test Flight (#Insider VIDEO)

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Originally published on 1Sun4All.

Solar Impulse 2 is performing ground tests in preparation for its first test flight, which is expected in the coming weeks. In the run-up to the premier flight, we can watch the team’s preparations via video. In this edition of #Insider, we meet Si2’s Flight Test Engineer, Christoph, and the ground team runs the engines for the first time.

#Insider: The Sound of Solar Impulse 2

I’ve included some technical specifications about the solar cells and batteries that power Si2 from Building a Solar Airplane.

Solar Cells:
  • More than 17’000 solar cells, which represents 269.5 m2!
  • More precisely, 17’248 monocrystalline silicon cells each 135 microns thick mounted on the wings, fuselage and horizontal tailplane, providing the best compromise between lightness, flexibility and efficiency (23%).
  • In order to maximize the aerodynamical performance, the plane is built with a wingspan of 72m: wider than that of a Boeing 747 Jumbo Jet!

solar impulse 2Solar Impulse 2, 1st Outdoor Technical Tests, 2014.14.04 | © Solar Impulse | Revillard |


  • The energy collected by the solar cells is stored in lithium polymer batteries, whose energy density is optimized to 260 Wh / kg. The batteries are insulated by high-density foam and mounted in the four engine nacelles, with a system to control charging thresholds and temperature. Their total mass amounts to 633 kg, or just over a quarter of the aircraft’s all-up weight.
  • In order to save energy, the aircraft climbs to 8’500 m during the day and descents to 1,500 m at night.

There are several things we can do to participate and support Solar Impulse 2. More information is available here.

  • Collect this year’s badge.
  • Sign up for all the latest news.
  • Adopt a Solar Cell.
  • Become an “Explorer” and book a visit to see Solar Impulse 2.
  • The ultimate Si2 supporter is the “Pioneer” and this this level of support your name will be on the fuselage!

In case you missed the presentation in Payerne, Switzerland, you can still watch it here: Official Unveiling Of Solar Impulse 2 (LIVE VIDEO)

Check out our Solar Impulse history for more — we’ve been covering this crew since 2008!

Check out our solar news channel and subscribe to our solar or overall cleantech newsletter for even more.

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Amber Archangel

-- I am an artist, painter, writer, interior designer, graphic designer, and constant student of many studies. Living with respect for the environment close at hand, the food chain, natural remedies for healing the earth, people and animals is a life-long expression and commitment. As half of a home-building team, I helped design and build harmonious, sustainable and net-zero homes that incorporate clean air systems, passive and active solar energy as well as rainwater collection systems. Private aviation stirs a special appeal, I would love to fly in the solar airplane and install a wind turbine in my yard. I am a peace-loving, courageous soul, and I am passionate about contributing to the clean energy revolution. I formerly designed and managed a clean energy website,

Amber Archangel has 195 posts and counting. See all posts by Amber Archangel

One thought on “Solar Impulse 2 Preps for 1st Test Flight (#Insider VIDEO)

  • You can see how getting around that pesky Shockley–Queisser limit is critical in these aerospace applications.

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