Into the night sky: Solar Impulse's solar-powered, single-pilot aircraft flew through an entire night on stored solar energy.
Francis Demange, Solar Impulse
Nighttime flight is an important milestone--but solar power is unlikely to transform aviation.
Swiss researchers yesterday marked a major milestone in the development of a solar-powered, single-pilot aircraft that they hope will eventually circumnavigate the globe. They kept their craft aloft through an entire night on stored solar energy.
In the wake of the event, the pilot, André Borschberg--CEO and cofounder of the Solar Impulse project--declared: "I have just flown more than 26 hours without using a drop of fuel and without causing any pollution!" The plane took off from a Swiss airbase early Wednesday and landed there at dawn Thursday.
Of course, it is a long way from this stunt to an aviation industry that isn't reliant on energy-dense jet fuel to hoist hundreds of thousands of pounds of cargo and passengers to cruising altitude. Unlike cars--which can today drive respectable distances on stored electrical energy--commercial aircraft will be dependent on liquid fuels for a long time.
But the Solar Impulse plane does include some novel engineering feats. Its wings are covered with 11,000 solar cells, and it uses lightweight composite structural parts and has a wingspan of 210 feet, not far from that of the world's biggest commercial jet, the Airbus A380, which has a wingspan of 260 feet. Keeping the plane's weight down to 3,500 pounds required optimizing electrical components in order to keep battery size as small as possible. The design was honed with computer modeling help from the European Space Agency and the Swiss Federal Institute of Technology. Still, the plane must fly at a pokey 28 miles per hour to save electricity. The lessons learned from the test flight will be used to develop an improved version of the plane that would attempt to fly around the world.
"It's good engineering, as you would expect from a Swiss team," said John Hansman, professor of aeronautics at MIT. But while the project is interesting, he says: "Solar will be a niche application for aircraft. It's hard to have enough energy capture to use for transportation, and solar cell efficiency is not high enough."
Despite their dubious commercial potential, lightweight solar-powered planes could be crucial to conducting long-term surveillance, and that's why various governments, including that of the United States, have been researching the technology. NASA's solar-powered Helios aircraft, one such unmanned effort, disintegrated due to turbulence during a 2003 test flight.
In 1999, the leader of the Solar Impulse project, Swiss adventurer Bertrand Piccard, became the first person (along with his copilot) to fly nonstop around the world in a balloon. "This is a highly symbolic moment," he said in a statement yesterday. "Flying by night using solely solar power is a stunning manifestation of the potential that clean technologies offer today to reduce the dependency of our society on fossil fuels."
Applied Materials makes the equipment needed to produce the biggest solar panels in the world.
To gain a better understanding of ice-sheet disintegration, Kansas researchers are building an unmanned plane with cutting-edge radar for better mapping.
I don't see solar aeronautics as revolutionizing human and cargo transport. But certainly in unmanned aircraft there is a very significant potential. Solar aircraft that can fly indefinitely with the kinds of payloads used in communications, earth observations, weather, climate, ocean research, mapping, GPS - basically anything a satellite is used for - a solar plane option would really be a huge innovation. Far cheaper, easier to deploy, can hover over areas where geosynchronous orbits are impossible. Huge, huge potential.
...just not for large, fixed-wing aircraft. What is likely to happen is: as soon as it's possible to add super-lightweight solar cells directly to fabric we'll start to see quite a few Para-gliding pilots using the currently available lightweight electric motors together with these solar cells built into their canopy's material.
It will allow easier starts and longer flights -- even 4-5 min of electric powered flight can greatly extend the total flight time. When thermals are available, then the motor is turned off and a small battery would re-charge, ready for the next short burst of powered flight.
As solar tech improves, this low-end use will slowly creep up to larger and heavier aircraft. :-)
article underscores a partial cure for contemporary addiction to wired transmission of electric current, powered flight being center stage...
yes, engineers notice absence of hybrid technology in heavy industries, transportation sectors, especially so in aircraft propulsion as outlined here .....
there is no green reluctance to tap into solar energy en toto, for a century plus, dwelling in a comfort zone where energy transfer through wires has been the norm, lack of corresponding progress in superconductivity fields have reduced the efficiency of propulsion mechanisms considerably and stirred us out of our sense of complacency.
wireless transmission of electric current through urban and suburban settings may not be practical, and objectionable to utility producers and consumer interests alike. Au contraire environments under automotive, locomotive, marine and aircraft hoods pose far fewer obstacles, albeit considerable din and clamor generated by progress itself compels further thought to the subject.....in order to effect practical use of partially efficient solar collector panels, the study of alternative avenues for transfer of energy needs a transfusion, if during the course of inquisitiveness knowledge is unearthed to capture and utilize energies of starlight, moonlight etc., all the better for it we will be.
The Solar Impulse project IMHO is an extension of the spirit of Kitty Hawk, a step for future aviators gliding towards the morrow's sunrise,
What if such aircraft were equipped with a small turbojet, providing elecrical power and some thrust. Given the small physical size of the turbojet, it could be turned off when not needed, such as during daytime cruising and descent. The aircraft's electrical propellars would replace the fan and provide most of the thrust.
While taxeing, the system could possibly be powered by grid electricity.
I have also read something (technology quaterly, Economist?) about cars embedding lithium battery technology into its carbon composite structures. This must be an even better idea in an aircraft - one would assume.
no point adding excess weight like a wind farm up there to it....Solar cells are light weight electrical generators and hence they are perfrect for it.
They were researching plastic batteries a decade or so ago, in essence the whole car body could be a battery. Not sure what happened to that line of research, sorry.
I would say its (current) day to day function would be unmanned surveillance using extremely sensitive equipment that could integrate with satellite imagery when the satellites are out of range.
Applying this type of electrical system to a He filled Blimp has far more potential. A much greater surface area for solar cells and a minimal fuselage weight provides a much greater useful load.
... and while on my soap box can we start calling UAV's more appropriately RPV's for remote piloted vehicles and APV's for autonomous piloted vehicles. Much less scary to the public.
Not that we dont doubt the justification of turning a blimp into a continuously flying vehicle.
But i fear if it went into enemy territory they would see an enormous slow moving blip on their radar, moving towards that gathering of (infidels) leaders who just happen to be meeting on that hill. Then have time to call them up and say we have an enormous blip heading towards you....
Oh and by the way lets send a few of our blips to shoot down the blip.
The drones radar signature would be less while being more maneouvreable. In essence it could flee much faster and also becuase its a nice missile shape (and would be) packed with high impact explosives could be used itself in a last resort.
Or, you can use the blimp as a mobile charging platform to charge up the batteries of non-solar planes.:)
They should fill wings etc with hydrogen.
Man inside would be useless but 2nd one would be doubly useless auto pilot with gps and satellite communication would be simpler.
Ultimately though, Frisbee shaped airship with doughnut air tube would be ideal.
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67 Comments
What no one reports
This story just generates a lot more questions for me. I'm wondering especially whether they took off with fully charged batteries. No one seems to mention this in reporting this story. Of course it might seem silly to have depleted batteries on take off, but on the other hand if you are trying to prove you can fly solely on solar power, and indefinitely, it would be necessary in order to discern between solar power and battery storage. I don't know what their battery capacity is, but obviously there is enough to fly through the night only on the batteries without touching down. (I don't imagine the plane can glide at night for 10 hours.) So if the batteries are fully charged then they have quite a boost already on takeoff.
To prove that the plane can fly indefinitely, you will need to take off with depleted batteries, or, which is the near equivalent, go at least 48 hours. The second 24 hours would be the key. In that case, you will have fairly depleted batteries at dawn after the first night, and will need to both gain altitude and recharge your batteries completely in order to make it through the second night. If they can go 48 hours then yes, indefinite flight should be possible.
The other question is how a single pilot stays awake that long. But that's a human question!
Reply
wilnix
1 Comment
Re: What no one reports
I see no reason why the aircraft would have to leave the ground with depleted batteries. Surely the solar panels are effective when the aircraft is on the ground, and the charging mechanism is fully functional.
Reply
blazer2000x
1 Comment
Re: What no one reports
The "real test", as you put it, is coming. The plane will fly around the globe, purely on solar energy. As for the pilot, the next model will seat two people, who will fly the plane in shifts.
Regardless of whether or not the batteries were full when it took off (they probably were), this is an impressive feat.
Reply
bogdanp
2 Comments
Re: What no one reports
Actually, someone reported: http://www.solarimpulse.com/nightFlights/charts.php
The batteries were charged 70% at start.
It would be more interesting to learn how much help the plane got from the thermals. There are plenty of them in the Alps and an experienced pilot can keep a glider "indefinitely" in the air.
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