The June 2024 issue of IEEE Spectrum is here!

Close bar

Solar Plane Passes 24-hour Endurance Test

Stores enough sunlight to stay aloft overnight

1 min read

Solar Plane Passes 24-hour Endurance Test


Photo: Fabrice Coffrini/Reuters
Click on image for a larger view.

This sleek aircraft, the Solar Impulse HB-SIA, remained aloft for an entire day in July, completing the first-ever night flight for a solar plane. During the day, the 11 628 monocrystalline silicon solar panels blanketing its wings—63 meters from tip to tip—generated enough electricity to power its four 7.46-kilowatt motors and top up its 70 polymer lithium batteries. The batteries' 96-kilowatt-hour total capacity was enough to keep the plane cruising along at an average of 70 kilometers per hour between dusk and dawn. Designers are working on a version with lighter batteries that will circle the globe without touching down.

This article originally appeared in print as "Traveling Light."

This article is for IEEE members only. Join IEEE to access our full archive.

Join the world’s largest professional organization devoted to engineering and applied sciences and get access to all of Spectrum’s articles, podcasts, and special reports. Learn more →

If you're already an IEEE member, please sign in to continue reading.

Membership includes:

  • Get unlimited access to IEEE Spectrum content
  • Follow your favorite topics to create a personalized feed of IEEE Spectrum content
  • Save Spectrum articles to read later
  • Network with other technology professionals
  • Establish a professional profile
  • Create a group to share and collaborate on projects
  • Discover IEEE events and activities
  • Join and participate in discussions