I’m trying hard to avoid making the “it’s a bird!” jokes, but this solar powered plane certainly packs a punch in the sky! How gorgeous! Presenting Solar Impulse, a photon-fueled, flying phenomena hoping to soar above your head soon. A project undertaken by Bertrand Piccard (co-pilot of the first balloon to circumnavigate the world) and André Borschberg, the plane has successfully completed journeys taking place in both daylight and night.
The plane relies entirely on solar energy, from take off to landing and beyond. HB-SIA, as it is identified, has lasted over an entire diurnal cycle, 26 hours to be exact. Extraordinarily efficient, the plane can continue flying overnight, with the batteries completely refueling . With temperatures of -40°C reached at 8,500 meters, the plane even recycles the heat generated by the batteries.
Form follows function, and oh does the HB-SIA have style. The wingspan of an Airbus A340 is adorned with almost 12,000 photovoltaic cells which charge lithium-polymer batteries. The cells chosen are monocrystalline silicon cells, each 150 microns thick. According to Solar Impulse’s fascinating HB-SIA brochure, “At 22%, their [cells] energy efficiency could have been higher, but the additional weight would have penalized the aircraft during night flight. In this, the most critical stage, the major constraint of the project is storing energy in the lithium polymer batteries. At the present stage, the maximum energy density is 220 Wh/kg. The accumulators needed for night flight weigh 400 kg, equal to ¼ of the total weight of the aircraft. Success is therefore possible only by maximizing aerodynamic performance and optimizing the energy chain.” The large wingspan minimizes induced drag and offers as much area as possible for cells to harness sun energy. Despite the immense width of the plane, it weighs about the same as a car!
Best of all, Solar Impulse is not resting on its laurels–the team is itching for more. The speed of the plane is quite slow in comparison to its hefty shared wingspan Airbus A340, or in fact most jets we are familiar with, but it’s still an immensely impressive plane. The second version of the plane, HB-SIB, will begin retracing aviation history, starting with crossing the Atlantic Ocean and United States of America and culminating in a circumnavigation of the globe!
I love the “Here’s to the Crazy Ones” mentality of Mr. Piccard:
«If an aircraft is able to fly day and night without fuel, propelled only
by solar energy, let no one claim that it is impossible to do the same
thing for motor vehicles, heating and air conditioning systems and
computers. This project voices our conviction that a pioneering spirit
with political vision can together change society and bring about an
end to fossil fuel dependency.»
Bertrand Piccard
Thank you to Boston’s Big Picture blog for the title image, and Solar Impulse for the rest.
(Now I’m ITCHING to design a pair of solar-powered wings for myself. Any tips?)
