NAV20 From Australia, joined Nov 2003, 9746 posts, RR: 37 Posted (3 years 5 months 1 week 1 day 19 hours ago) and read 2941 times:
You have to admire the guys who put this thing together. They've 'crossed the divide' in a way - a solar-powered aeroplane that (in good conditions) can 'bridge the gap' by storing enough power in daylight hours to fly through the night as well.
On the one hand that achievement may turn out to be meaningless - the thing looks to be light-years away from ever being able to carry a useful payload at anything like a reasonable speed. But on the OTHER hand, that's what a lot of people thought about the Wright Brothers' achievement back in 1903........
'Well done' to the guys concerned, anyway. It must have taken a lot of guts to fly on 'into the night' in that thing, and then just 'watch the gauges' and hope that the power lasted until daylight. Especially since, in the interests of keeping the weight down, the designers didn't fit any 'luxuries' like an autopilot......so the flight was 'hands on' all the way.......
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
BMI727 From United States of America, joined Feb 2009, 15094 posts, RR: 26 Reply 1, posted (3 years 5 months 1 week 1 day 19 hours ago) and read 2875 times:
Quoting NAV20 (Thread starter): the thing looks to be light-years away from ever being able to carry a useful payload at anything like a reasonable speed
I wouldn't say that. First, speed may not be important at all. Also, don't forget that the plane was manned. A UAV version should have weight to spare for carrying some reasonable small sensors. As a transport, I don't think solar is the way to go, but for long endurance surveillance applications it may be perfect.
Why do Aerospace Engineering students have to turn things in on time?
BooDog From United States of America, joined Nov 2007, 253 posts, RR: 0 Reply 3, posted (3 years 5 months 1 week 1 day 17 hours ago) and read 2655 times:
There's so few threads I can fully contribute to, since I'm not a pilot and I don't work in aviation. But I work in renewable energy, so here it goes.
"Solar impulse" is just a demonstration project to show off the latest solar technology development. And what is that development? Solar power to weight ratio. That is all. It's not a big deal. There's a possibility of seeing the plane's power and cabin systems shifted away from the engines and towards solar panels on the wings in the future. This will only happen if the "power shift" can add more fuel economy to the engines; enough to overcome the extra weight of the solar components.
I do not expect to see solar-powered cargo and passenger planes in the next fifty years. But you may see many solar-powered planes in the general aviation field ten/twenty years from now. The most likely benefit from "Solar Impulse" technology is the adding of solar panels to hybrid/plugin cars to gain an extra 1 or 2 miles per gallon.
BMI727 From United States of America, joined Feb 2009, 15094 posts, RR: 26 Reply 4, posted (3 years 5 months 1 week ago) and read 2184 times:
Quoting EBGARN (Reply 2): Just give it another ten years or so, and it might be useful for UAV cargo as well.
I don't know if these solar powered planes will ever be cost effective enough and have the necessary payload to carry cargo loads. It seems to me that if you want to haul a bunch of stuff a long way but speed isn't important an airship would probably work better. I have seen a concept or two to that effect.
Why do Aerospace Engineering students have to turn things in on time?
MD11Engineer From Germany, joined Oct 2003, 13604 posts, RR: 63 Reply 5, posted (3 years 5 months 6 days 20 hours ago) and read 2025 times:
This plane has been demonstrating low weight, high capacity batteries, which can also be used in other applications, where the bulk, weight and limited capcity of traditional rechargeable batteries is a serious obstacle, e.g. in cars. I imagine that at the moment these high tech batteries are very expensive, but I´m sure that in future they can be made cheaper.
The big problem at moment with alternative energy sources, like wind, water and solar energy is the uncertainity of availability (e.g. calm winds, drought or cloudy skies as opposed to an overload if there is plenty of sun, the rivers are flowing and there is plenty of wind) and the lack of the ability to store the excess energy generated in good times to be used during bad times.
MD11Engineer From Germany, joined Oct 2003, 13604 posts, RR: 63 Reply 9, posted (3 years 5 months 6 days 16 hours ago) and read 1803 times:
Quoting BMI727 (Reply 6): Quoting MD11Engineer (Reply 5):
the lack of the ability to store the excess energy generated in good times to be used during bad times.
I think that supercapacitors may offer the best hope there.
Supercapacitors are good for quick access at high currents, but for stationary applications, where weight and size doesn´t matter, I´d rather look into the direction of redox cell accumulators. Basically these accumulators use two liquid chemicals, which under influence of electric current get converted into two new chemicals:
A + e- ----> B and C ----> D + e-
The reagent pairs A and C, respectively B and D are seperated in the reaction chamber by a diaphragm, which is only permeable for the electrons, but not for the larger chemical molecules.
The reaction is reversible, so that B and D can react again to form A and C and at the same time produce electric current.
Basically you´ll need four chemical holding tanks (one each for A,B,C and D), a reaction chamber and the respective plumbing (pipes, valves, pumps). The capacity of such a system is only limited by tthe size of the storage tanks.
Quoting MD11Engineer (Reply 5): The big problem at moment with alternative energy sources, like wind, water and solar energy is the uncertainity of availability (e.g. calm winds, drought or cloudy skies as opposed to an overload if there is plenty of sun, the rivers are flowing and there is plenty of wind) and the lack of the ability to store the excess energy generated in good times to be used during bad times.
This perception is certainly fueled by the oil folks.
But if you look at US cities like Laughlin, Nevada - right on the Colorado River - you have to shake your head a bit.
Thanks to the treehuggers, it is virtually impossible to build a few small dams and derive hydro power from the huge amount of energy flowing right past the casinos 24-7.
Laughlin is an especially odd bird in this respect - all day and well into the night, taxi barges equipped with pairs of 200hp outboard engines transport people from one casino to the next, via the river. It's okay for the city to waste that energy just to enhance the "experience," but too hard regulation-wise to do anything else with the flow!
Quote: If you are a government or a huge multinational company, this is fairly Significant. For Average Joe, its near meaningless.
True, at least for the time being. Fortunately, the "drain-down time" of technology like this has gotten much shorter.
Quote: But you may see many solar-powered planes in the general aviation field ten/twenty years from now.
Just how cool would that be!? Your "Cessna" sits around charging itself up for your next flight!
I don't see the efficiencies going up enough any time soon, but - eventually - could your plane generate enough power to sell back to the airport?
The ultimate would be a "virtual" power grid, where all the extra power generated at home, by your car, by your airplane, boat, et cetera, could go as credit to lower your costs when you do have to draw from the grid.