Solar-Powered Plane Makes Runway Debut 120
MikeChino writes "The much-hyped Solar Impulse airplane just completed its first runway test, paving the way for a 20-to-25-day trip around the world next year. Conceived by Bertrand Piccard, the single-pilot plane successfully used its four solar powered motors to taxi around the runway. If all goes according to plan the plane will be able to fly day and night without fuel, signaling a bright future for solar-powered flight."
NASA already has a Solar UAV (Score:3, Informative)
http://www.youtube.com/watch?v=5oNHD41MLMk [youtube.com]
But a manned plane would be pretty neat. Hope it has enough batteries for the night - the solar UAV does a lot of gliding, which might not be possible with a heavier aircraft actually attempting to get somewhere.
Re:until storm/nightfall/eclipse hit (Score:5, Informative)
RTFS!
"If all goes according to plan the plane will be able to fly day and night without fuel, signaling a bright future for solar-powered flight."
Re:Commas (Score:5, Informative)
Have a look where the design team and the sponsors come from.
Re:night and day? (Score:3, Informative)
Hydrogen is an energy transmission device, it's never been a SOURCE of energy. We can't "mine" hydrogen or produce it out of nothing.
Uh, yeah, that's what I said, asshole. We lose around 5% of our electrical power in transmission in this country (including conversion related to transmission.) The efficiency of hydrogen through electrolysis is under 60% in basically all real-world cases. Can you see why Hydrogen is fucking stupid, given that it is prohibitively expensive (in terms of energy cost) to make, and that the other forms of hydrogen ARE in effect mined, since again we make most of it from Natural Gas? Which, BTW, comes from wells, we don't make it. We crack the hydrogen out of natural gas in conceptually much the same way we crack the useful hydrocarbons from crude before we burn them in our cars.
You could make the argument that hydrogen electrolysis would work for solar or wind farms to store generated energy, but I have no idea how efficient that would be. I'd imagine it would need to be on a very large scale to be worth it.
Maglev-bearing flywheels are cheaper to build, easier to contain (bury them) and more efficient to store power in. Hydrogen is a boondoggle looking for justification. The only case I can think of where it would actually be useful is in fork lifts, where it would be even cleaner than running them on propane. The problem there is that flywheels need a lot of counterweight and as such are perfect candidates for counterrotating flywheels, which can be spun up rapidly with a variety of technologies.
Re:night and day? (Score:3, Informative)
Actually, hydrogen has very good energy density by mass (the best of any chemical fuel). By volume, it's very poor. That's why you see hydrogen used as a fuel for rockets (where mass matters much more than volume), but not aircraft. A commercial airliner running on hydrogen would require a huge insulated tank that would add lots of weight and drag; you can't just tuck the fuel into the wings like you can with jet-A. It may become usable for small aircraft, but I don't think you'll see it used for anything larger (except maybe super-high-altitude UAVs and exotic hypersonic vehicles).
However, I do agree that biomass-based synthetic fuels will be far more prevalent in the future. Assuming we don't try to force the use of inefficient food crops for production through heavy-handed government and lobbyist actions (coughcorncough), and instead focus on using mroe efficient plants, algae, and leftover/waste biomass, it will likely work out. I know that there are already a few promising replacements for piston-engine avgas and [avweb.com]diesel and jet fuel [avweb.com] under development, and I think such things are a far better investment of funds for several reasons. They are essentially carbon-neutral once applied on a large scale, they eliminate strategic and economic dependence on politically volatile nation-state cartel members, and they are essentially "drop-in" replacements for current fuels, allowing current infrastructure to be used and changed over much more cheaply than drastic changes.
Re:Better site? (Score:2, Informative)
You didn't look very hard, did you?
TECHNCIAL DATASHEET
Wingspan: 63,40 m
Length: 21,85 m
Height: 6,40 m
Weight: 1 600 Kg
Motor power: 4 x 10 HP electric engines
Solar cells: 11 628 (10 748 on the wing, 880 on the horizontal stabilizer)
Average flying speed: 70 km/h
Take-off speed: 35 km/h
Maximum altitude: 8 500 m (27 900 ft)
http://www.solarimpulse.com/en/documents/challenge_solar.php?lang=en&group=challenge [solarimpulse.com]
Re:NASA already has a Solar UAV (Score:3, Informative)
A better example is Air Transat Flight 236 where an Airbus 330 glided about 100 miles to a landing.
http://en.wikipedia.org/wiki/Air_Transat_Flight_236 [wikipedia.org]