Guest essay by Eric Worrall
The Solar Impulse 2 has finally completed completed the latest leg of its round the world flight. In engineering terms, a round the world flight using solar power is a remarkable achievement. But the difficulty of achieving this feat showcases why solar energy will never be a viable replacement for fossil fuels.
An experimental plane flying around the world without a single drop of fuel landed in California after a two-and-a-half day flight across the Pacific.
Piloted by Swiss explorer and psychiatrist Bertrand Piccard, Solar Impulse 2 touched down in Mountain View just before midnight (3 a.m. ET).
“It’s a new era. It’s not science fiction. It’s today,” Piccard told CNN from California after his successful voyage. “It exists and clean technologies can do the impossible.”
Images of the elegant solar aircraft, which has the wingspan of a Boeing 747 but only weighs about as much as an SUV, flying over the Golden Gate Bridge into San Francisco Bay mark a significant achievement. The team has seen the project beset with problems and setbacks during its pioneering airborne circumnavigation.
…
“I’m very happy that everything works extremely well and the airplane is functioning as it should,” Piccard’s business partner and the plane’s other pilot, Swiss engineer Andre Borschberg, told CNN by phone from California just ahead of the successful, on-schedule landing.
“It’s a demonstration that the tech is reliable.”
The plane took off from Hawaii on Thursday, resuming a journey that had stalled on the island of Oahu for almost 10 months.
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Read more: http://edition.cnn.com/2016/04/24/travel/solar-impulse-2-plane-california/
Solar planes can’t carry meaningful amounts of cargo. They can barely carry passengers.
I am not disrespecting the talent of the engineers who achieved this feat. Flying a solar plane around the world is a remarkable achievement. But this achievement does not demonstrate the technology is viable. What it demonstrates is that solar is a ridiculously poor source of power. A solar collector the size of a 747 just managed to collect enough electricity, to keep an incredibly lightweight plane aloft.
Just like solar panels, solar planes might find some niche uses, such as long life high altitude robotic observation platforms, or even as mobile telephone repeater stations – solar planes are not restricted by fuel payload, and can reach very high altitudes, because they don’t depend on burning fuel with oxygen for their power.
Solar planes will never replace fossil fuel powered planes, for ferrying people and high value cargoes across vast distances.
Update (EW): h/t etudiant – the flight is not yet complete…
each engine in a 777?
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GE90 is 50 megawatts, or about 67,000 horsepower. Approximate unit price is $24 million
so, for 50 megawatts of power, with each solar panel putting out about 200 watts, you would need about 250,000 solar panels. 25+ million dollars worth of panels.
So, the solar panel is actually price competitive, the problem is the weight of 250,000 solar panels. The GE90 is something like 4hp/lb. Solar panels maybe 0.025 hp/lb. All the power is required to carry the panels.
Not to mention the area required for the solar panels.
Reliable? They fried the batteries on the Japan/Hawaii leg and had to raise $25million to replace them. It is really not even the same plane that started out $170mil ago. http://www.theguardian.com/environment/2015/jul/27/solar-impulse-round-the-world-flight-raise-20-million-euros
betapug April 25, 2016 at 7:50 pm
Hi thank you for the link I took this away from it.
“Two months’ delay meant the end of the circumnavigation for this flying season – the second Pacific leg cannot be safely flown after mid-August.”
So that is the real reason for the delay, can’t fly after August. Reliable??
michael
Notice the pilots clothing, no heater I guess that would use up energy.
A friend of mine did a circumnavigation crossing the oceans in a rowing boat. His Pacific crossing was a bit faster than this flying machine.
http://www.around-n-over.org/projects.htm
Maybe we could provide everybody with an oar to generate power for travel.
Would that be an ‘exclusive OR’?
Did you know that if you take 3 oars and link them at the tips…
.. you get an E-oar. !
Well… There was a time when the US Air Force was thinking about designing a “Nucklar” powered intercontinental bomber…
That plane never did get off the ground…
This Solar plane did get off the ground, so we have to give them some credit for that….
But a year to go around the Earth ??? Really…… This is not a credible airplane with any real uses…
Like I’ve heard; “A Fool and His Money Are Soon Parted”, or something like that…
Cheers, KevinK
They’d be afraid to shoot that one down!
NB-36H had a few flights (40 something iirc) but it used the normal 6 turning 4 burning method of propulsion. pretty much only tested shielding on the reactor.
They didn’t even get around the Earth.
besides the bragging rights why did they risk the lives of the 2 pilots when the plane could easily have been piloted remotely …?
Yeah the first James Watt engine was pretty useless too.
The depth of self-deluded thinking here is quite impressive. If you can’t see potential in this either you’re willfully ignorant or just lack imagination.
And the first electric motor (1830 first electric car) was pretty useless too.
However, putting the two together have developed into diesel electric. Now there’s a mobile power house if ever I’ve seen one.
There’s a whole area of being ‘fit for purpose’. This is a fun project and has no avenue for future development.
180 years later, the electric car is still pretty much useless.
Who told you Watts first engine was useless??
evcricket, explain the potential for those here. Other then perhaps long duration remote surveillance, what do you see Do you see commercial flight capacity?
Actually, James Watt’s first steam engines worked pretty darned well. Of course, Watt’s engine was merely an enhancement of Thomas Newcomen’s steam engine, which had a number of drawbacks, among them losing power when the boiler cooled off too much. Watt’s external condenser solved that issue, among others.
But the Watt/Newcomen engines (and the generations of earlier designs) weren’t limited by some absolutely fixed maximum power, while solar powered airplanes ARE. Solar cells are nowhere near 100% efficient, but even if they approach that efficiency, they’re limited by the area of solar panels that can be deployed, and by the WEIGHT of the solar panels to be carried. And the weight of the batteries needed to keep aloft at night.
Perhaps someday, in some science-fiction future where solar power satellites can beam power via MASER to rectennas on the wings, it may be possible to construct “solar powered” aircraft capable of carrying some payload or passengers. But this is a stunt. A glorious stunt, but a stunt.
kenwd….your post is the second in this thread discussing beaming energy to the plane from space. Why not go all the way use a nuclear satellite and shoot the damn thing down with a proton beam weapon? More bang for the buck and truly at the frontiers of applied technology!
Precise beam control and collimation will enable to transfer enough power to make it fly, without transferring so much power to destroy it. Destruction is easy, especially if you have a MASER in GEO with sufficient power and skill to aim it. I want to provide more delicate power, CONTROLLED power.
Please tell oh omniscient one, what is the potential that the rest of us ignoramuses are missing?
Or are you just being offensive for the heck of it?
If you can’t see the limitations in this you’re willfully ignorant or just lack some understanding of basic energy density limitations and power to weight limits. These are not going away with just “imagination.” Solar is inherently a high weight, low energy density power source. Trying to make it work in applications that make no sense is not a breakthrough, it is just silly.
I recall the Mythbusters making planes out of concrete for their tv show. They worked about as well as this plane and not one person looked at that episode and “saw potential” in concrete as an aviation material! Why? Because as this solar plane shows, making aircraft out of heavy things is poor engineering.
Guiding a landing U2 would be more fun than a bicycle. High performance mustang used with the U2, raw dino powered horsepower.
“The plane took off from Hawaii on Thursday, resuming a journey that had stalled on the island of Oahu for almost 10 months.”
The flight had not “stalled” for ten months. It took that long to rebuild the airplane because it almost didn’t make it from Japan to Hawaii. It’s taken nearly a YEAR to get HALF WAY AROUND THE WORLD. Captain Cook could have done it that quickly, and a clipper ship could bring tea from China to London in only a couple of months.
You know if they’d called it a solar-power-assisted Glider, and pointed out that it was travelling with prevailing winds etc, I could have applauded their mad-cap achievement. But to present it as ‘powered flight’ is insulting to the intelligence.
If it looks like a glider, and averages 40 mph over a long trip…it’s a ‘glider’.
FYI, gliders don’t have propellers.
Earthling, stop being a smug know-it-all.
https://en.wikipedia.org/wiki/Motor_glider
indefatigablefrog April 26, 2016 at 12:08 am
Earthling, stop being a smug know-it-all.
Ha! your “Flak” caught me too.
Thanks for the link, good information. Now I know better.
michael
Huh?
Nice, friendly response from indefatigablefrog.
I guess they have not yet harnessed theBarsoomian Eighth Ray.
Or E.E.Doc.Smith’s metal “X” 🙂
https://en.wikipedia.org/wiki/Skylark_(series)
The plane took off from Hawaii on Thursday, resuming a journey that had stalled on the island of Oahu for almost 10 months.
You’d need a pile of meal vouchers on any commercial flight with a layover that long.
Be cool to fly solar, soon as I get my wife past the fact she has to pee pee through a hole in the seat.
I assume that no coal was burnt in the fabrication of the plane, and that no fossil lubricating oils were consumed, and that the support team did not fly on commercial airlines but used wind-powered yachts.
Before mocking any innovation, look back to see what was done previously.
In 1916, a few years after Bleriot flew across the English Channel in a single seater monoplane, a war was being fought that included biplanes and triplanes made mostly from wood and canvas using rotary engines.
Maybe solar powered flight will be the accepted form of transport in 2116, who knows?
For the record, I have my doubts, but in 1920, some people were wondering where all the horses would be stabled in the year 2000. Ö¿Ö
“Maybe solar powered flight will be the accepted form of transport in 2116, who knows?”
Isn’t this called argument from ignorance?
Actually, we do know that it won’t. Because whilst engine power could be scaled rapidly to suit the needs of propelling heavier and heavier aircraft across the sky on longer and longer journeys – we know that we can not increase the power of the sunlight falling on the upper surface of an aircraft in the same manner.
We can increase the efficiency of the panels towards over time. But never beyond unity.
So the fundamental physical limit will always exist.
Perhaps we can make these vehicles bigger and bigger and eventually carry a small crew and a handful of passengers on novelty flights – at extreme danger to all involved.
In which case we can look to history and see that the technology would be more akin to the development of the giant airships of the early 1900’s.
Only, more stupid and costly and probably less effective.
We can always add a really large lens to the plane :)))
Alternatively, we can use gravity generator to create gravity lens to focus light from much larger area.
Or we can use teleported at the sun to beam energy directly into the plane. Now that would really be solar powered!
And one mustn’t forget magic. There is always magic spell or to get sun to shine brighter on your plane.
Yes, these are extremely practical suggestions.
In fact, in the early years of the development of airplanes, it was common to use both the principles of engineering and magical incantations in order to successfully transport people through the sky.
Hence the expression “on a wing and a prayer”.
Of course, the political left are no longer interested in transforming the world via praying.
They will simply mandate that commercial solar planes must fly by passing a law to that effect.
The laws of physics must be conformed to the laws of man.
Who’s a smug know-it-all?
Well, it takes one to know one!!!
As long as everyone is having fun.
This is only a silly internet blog thread, after all. Nobody gets fined or assassinated!!
Flying from direct sunlight will never be suitable as that can’t provide enough power even not with 100% efficiency of the solar panels for any commercial flights. The only probable alternative is with batteries loaded with solar/wind/hydro/geo on the ground – if you like to fly “renewable” – or nuclear or fossil if it doesn’t make a difference for you…
The main problem then is the very poor ratio between stored energy and weight / volume, both important for long distance flights. It will cost a lot of research to get that substantially better. Only then such flights may have merit, as good as for 100% electric cars…
There are some who’s mind’s are so open, that their brains have fallen out.
All of the technologies being used here are quite mature. Where is the improvement going to come from to take this from a toy to a useful product?
“There are some who’s mind’s are so open, that their brains have fallen out.”
ha! great line!
Those props on shafts, those shafts would not be lubricated by OIL, would they, destroying the Utopian nobility of ‘no fossil fuel’? Maybe they have plastic bushes, but if so, no doubt the plastic was not made from natural gas or other fossil fuels.
It’s an expensive joke. No points for credible effort.
No need for fossil oil. They could have been lubricated with whale oil but somehow I can’t seem to picture the WWF or Greenpeace killing a whale and rendering the oil to use in their plane. 🙂
[youtube https://www.youtube.com/watch?v=arQ8_PW-RiA&w=640&h=360%5D
Sorry, should have left a comment with the above link.
Good spoof of electric cars (or anything else that is large, heavy and needed to move more than a grain of rice.
Is this a case of ‘First they make fun of us’ etc, etc “Then we win”? Probably not.
Hilarious!
I just bought an SUV. I looked at the Mitsubishi PHEV. 50kms, if you are lucky, on batteries 1.9litres / 100kms. 30mpg on diesel. HTF is that saving the planet. My nearest town, of sorts, is 50kms. So I would have to drive to town, stay the day, come back before dark with a battery not fully charged if it was battery only car.
It’s a useless technology. Yes some time in the very distant future someone might come up with a battery solution for power but, hey, the energy density would need to be similar to FFs and charge time about 5 mins.
Stephen if they ever get a battery up to the power density of fossil fuels I would not want to be anywhere near it let alone sit on top of it inside a car. Batteries are very dangerous because they cannot be shut off. I maintain inverter power supplies at work and it is scary to work on large banks of batteries. Storage batteries have a very low internal resistance and will supply a huge current into anything that shorts out the terminals and this can lead to the battery exploding. I can not imagine how big the explosion would be from a shorted “fossil fuel” power density level battery bank. I think I will pass.
It’s good to see some of this stuff getting parodied in popular culture. It’s a welcome change from the ra ra hype of the late night comedians.
The crucial question about new technology is whether a breakthrough is required to make it work. If a breakthrough is required, all the money in the world might not be enough to bring about the technology. Our fearless leaders don’t understand that.
With current technology, electric airlinerss are impractical. We need a breakthrough in energy storage. I wouldn’t bet on it happening any time soon.
There is a book that everyone planning technology needs to read and understand:
In other words, breakthroughs happen when we stumble over them. They can’t be forced into existence.
Anyone who thinks this solar powered airplane presages solar powered airliners is living in cloud cuckoo land.
What will presage electric airliners will be the mother of all breakthroughs in energy storage.
Another AI researcher Ken Stanley achieved a similar insight.
https://wattsupwiththat.com/2015/04/02/the-search-for-novelty-in-science/
🙂
Three books would provide an innoculation against charlitains:
Why Greatness Cannot Be Planned by Stanley and Lehman
Expert Political Judgment by Tetlock
The Master and his Emissary by McGilchrist
Nobody should be able to get out of university without reading these three books. It would prevent so many stupid mistakes.
“It’s a new era. It’s not science fiction. It’s today, It exists.” Piccard told CNN from California after his successful voyage.
And that was actually what he said when, upon landing, he was informed that former male athlete Caitlyn Jenner had won Glamour Woman of the Year.
The sheer industrial brilliance and generations of scientific might that have enabled solar tech to fly – awesome. Can you imagine how shocked solar worshippers would be if you lifted the sheet on the industrial might and public coin holding the whole edifice up.
We’ll probably end up with renewable powered planes at some point in the next few decades due to this obsession. We’ll probably end up using hydro, wind, solar and biomass to generate energy to create a fuel, which we will then load into jet engines.
Or maybe we will power some planes exclusively from bio-fuels.
And everyone will say – “see, they said it couldn’t be done. A “solar” plane.”
Boringly, this will almost inevitably happen in the current political climate.
Meanwhile, we will be ignoring that vast quantities of perfectly suitable fuel lie beneath our feet.
Or maybe in the future socialist utopia, only members of the U.N. will be allowed to use planes.
So that they can attend urgent conferences on “saving the planet”.
Could have gotten a clue from solar powered cars. I don’t think they’re very practical either. Everything that’s supposedly renewable sure seems to take up a lot of space. Wind turbines, solar, ethanol….we will have no place left to grow food.
Just as they had to re-invent the windmill and rename it “wind turbine” in order to try to pretend it was something new and any better than the old windmills that were rejected so long ago, so if you want “renewable” transport, then the obvious answer is the good old sailing boat … with the obvious draw back that its a lot slower, more expensive, prone to piracy, requires many more people and basically much more dangerous.
That is why they constantly try to replace the sail with some kind of “hi tech” device that is basically a sail, but gives the impression it is something new and will break the laws of physics and make wind viable.
I believe some of the America’s cup sail boats use a “fixed” type sail which is more like a wing from an aircraft and much more efficient than a typical sail.
Hi from Oz.. Thanks for your insightful post Scottish Sceptic. That triggered another thought – I wonder if the (real) mech and elec engineers that they must use to design stuff like electric cars and wind turbines have moments of ‘cognitive dissonance’ where they realise the intrinsic futility of their work, or are they such green ‘true believers’ that they can ignore reality indefinitely? Or maybe they are just doing it for the money…
I think most of the engineers go into the projects knowing that the product is a political ploy, but have the integrity to try to make the vehicles as useful as the technology will allow.
Every real-world engineering decision is a compromise between cost and utility. There are certain safety bottom lines that can’t be crossed, but once those are covered, it is about making a product that will make the company money. Sometimes the product you design doesn’t make any money, but buys the company regulatory overhead to sell products that do make money. Thus you make a certain number of nearly useless electric vehicles in order to meet the CAFE standards to enable the sale of overpriced trucks and SUVs.
As an engineer, if I’m hired to build something, I will build it. The only time cognitive dissonance would come into play for me would be if the device I was building was for some kind of destructive purpose.
If the customer wants to waste his/her money, that’s the customer’s business, not mine.
If they ask my opinion, I will give them my honest opinion. If they don’t, then once again, that’s their business.
A lot of them get disillusioned in the cause. If they are doing it for the job, it’s nothing. However, if they think they are there to make a difference, then it’s frustrating beyond belief
I see the same with TCEQ employees. They go in thinking they are Planeteers and industry is evil, and then they end up issuing fines over incomplete paperwork and computer crashes. Some try and delude themselves that they are helping industry (permitting is the worst on this, as they often get the idea to “write permits for the common person” and come up with a result that is not easily usable by either expert or layman), but most others just get cynical and transfer to industry or private consulting.
A single man crossed the English Channel to France in a human-powered aircraft 37 years ago. Imagine what could be achieved if all the greenies were forced to travel this way to their protests.
Heck, they could even go to conferences in cold dark places where solar cells don’t work.
Even more interesting is the fact that the aircraft used, Gossamer Albatross, evolved into the Gossamer Penguin which was solar powered. A even later development, Gossamer Challenger also solar powered,flew from Paris to Manston.
It seems that little progress has been made in the past 30 odd years. The first round the world flight by conventional aircraft occurred in 1924, just 21 years after the brothers Wright first attained controlled powered flight. It would appear that development of solar flight is happening much slower than technologies that had some actual, as opposed to theoretical, potential.
Phileas Fogg would not feel threatened.