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Solar Impulse Plane Begins Epic Global Flight
An anonymous reader sends word that the Solar Impulse 2 airplane has begun its attempt to fly round-the-world powered by nothing but the sun. "A record-breaking attempt to fly around the world in a solar-powered plane has got under way from Abu Dhabi. The aircraft — called Solar Impulse-2 — took off from the Emirate, heading east to Muscat in Oman. Over the next five months, it will skip from continent to continent, crossing both the Pacific and Atlantic oceans in the process. Andre Borschberg was at the controls of the single-seater vehicle as it took off at 07:12 local time (03:12 GMT). He will share the pilot duties in due course with fellow Swiss, Bertrand Piccard. The plan is to stop off at various locations around the globe, to rest and to carry out maintenance, and also to spread a campaigning message about clean technologies."
Yeah, it's hard to imagine how this technology matters to most aircraft. Don't get me wrong, it's an impressive demonstration of how far you can go on a tiny amount of power, and there are a few applications where it might matter (e.g., high altitude drones). But one look at the amount of power it actually takes to push a commercial airliner (e.g., one Boeing 777 engine produces ~75 megawatts at full throttle) and you realize solar power is completely irrelevant for that application.
These kinds of articles where it's implied that someday we'll all be flying around in solar-powered planes are silly. It means they haven't done the math. Heck, even if you covered every square metre of a plane with solar cells you couldn't collect enough power. There's not enough there. Even if you charged up batteries from ground sources you couldn't carry enough storage and have the plane get off the ground because of the weight. Even with an order of magnitude improvement of power density you couldn't. The only way that solar could possibly be relevant for air travel is if you used the solar power to generate chemical fuels of some kind, with all the energy losses that conversion implies, and then put that chemical fuel into the plane. Aircraft is the one power demand where we will be using fossil fuels or their chemical equivalent for a long time. Weight, energy storage density, and efficiency matters too much for that application for it to be any other way.