From Slashdot, something so obvious you wonder why nobody tried it before: arrange solar panels like tree leaves for better efficiency. See the story and graphs I’ve provided below.
13-Year-Old Uses Fibonacci Sequence For Solar Power Breakthrough
An anonymous reader tips news of 7th grader Aidan Dwyer, who used phyllotaxis — the way leaves are arranged on plant stems in nature — as inspiration to arrange an array of solar panels in a way that generates 20-50% more energy than a uniform, flat panel array. Aidan wrote:
“I designed and built my own test model, copying the Fibonacci pattern of an oak tree. I studied my results with the compass tool and figured out the branch angles. The pattern was about 137 degrees and the Fibonacci sequence was 2/5. Then I built a model using this pattern from PVC tubing. In place of leaves, I used PV solar panels hooked up in series that produced up to 1/2 volt, so the peak output of the model was 5 volts. The entire design copied the pattern of an oak tree as closely as possible. … The Fibonacci tree design performed better than the flat-panel model. The tree design made 20% more electricity and collected 2 1/2 more hours of sunlight during the day. But the most interesting results were in December, when the Sun was at its lowest point in the sky. The tree design made 50% more electricity, and the collection time of sunlight was up to 50% longer!”
His work earned him a Young Naturalist Award from the American Museum of Natural History and a provisional patent on the design.
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Good for him! Here’s the output graphs:
It’s nothing new, here’s some that have been installed and working over a year, there are a few different designs in Sevilla
http://www.losbermejales.org/page/5/
Edison, Bell, (Both Alexander and later, Larry)the Wright Bros., Jobs and Gates, all started somewhere. Good job, laddie!
You never know…
Wonderful to see such enterprising and intelligent science done by a 7th grader in th ebackyard. Bravo!
Idiot.
REPLY: No relation – Anthony
Obviously, Anthony, you are well behind the ball on AGW – NEWSFLASH – Dire Warning for the planet!
NASA report says space aliens could invade earth to stop global warming
Seriously, you can’t make this stuff up!
I think a 2/5 Fibonacci sequence begins with 2, 5, 7, 12…
Aidan says: “I designed and built my own test model, copying the Fibonacci pattern of an oak tree.”
Personally, I would have used this as my test model.
DirkH says:
August 19, 2011 at 7:43 am
Nice idea, but i think it will go the way of Solyndra – complicated structures are more expensive than simple ones, so the simple one wins in the marketplace…
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Were it that simple… I have vertigo, so I would have to pay for someone to install flat panels on my roof. OTOH I have a backyard that is clear of shadows, and experience of flat-pack furniture.
Well far be it from me to get critical of an inquisitive 7th grader; I was one myself, I think.
Mother nature does some strangely optimal things at times. When some plants, send that very first green probe up out of the soil towards the sunlight, it is often true that the very common rounded end of that light probe, conforms to one of the Compound Parabolic Concentrator shapes, where light can enter from a wide range of angles, into the refractive medium, and is thence trapped by Total Internal Reflection, and light piped down to where the rest of the plant is, so the plant is solar powered right from its very first look at daylight. The branch and foliage structure of conifer forests is known to be quite efficient at light trapping. Pine forests tend to look dark from above, because sunlight can get down between the trees, but is largely prevented from reflecting back out. This is part of the reason that pine forests are among the few, that can grow in far northern environments.
Some species of shrimp or other lobster like creatures, have eyes that are also CPC geometries for efficient light collection.
However, one of the limiting efficiency factors of solar cell arrays, is uniformity of illumination; and/or local cell conversion efficiency.
Solar panels consist of large areas of parallel connected semiconductor junctions; and then series connection of such parallel arrays. Well in a parallel array of photo-Voltaic junctions, the cells that generate the highest Voltage, will tend to forward bias cells with lower illumination or efficiency, causing them to conduct currents shunting energy away from the load. The exact same problem was encountered by companies such as Westinghouse, when they first tried to make high powered rectifier diodes for power engineering. Westinghouse tried to make a single semiconductor junction diode, out of a two or three inch silicon wafer to make a several hundred or thousand Amp rectifier. Well local wafer defects acted as shunt paths, and such rectifiers tended to burn themselves up at local hotspots.
Lestert C Hogan at Motorola discovered that they could make a good silicon diode, up to about a maximum of 18 Amp forward current (peak). In fact they could make millions of them. But they tended to have different forward Voltages at any forward current. So Motorola sorted the diodes by forward Voltage at several differnt currents, and then they assembled parallel arrays of 18 Amp diodes, to make a high current diode “module”. Very small current matching interconnect resistances, balanced the current through the parallel diodes, and Motorola was able to take over the high power rectifier business. Those same 18 Amp diodes, are to this day in just about every automobile Alternator, made anywhere on the planet.
Series connected devices have the opposite problem; the current tends to be dictated by thw weakest cell in a series string. It affects automobile battery design, and is a significant proble for those with electric car wheels turning in their brains.
So deliberately building an array of solar cells, that are quite non-uniformly irradiated, is really a non starter. It is ok to have differnt illumination on different arrays; but ONLY if they are series connected. For any single array in a series stack, non-uniform irradiation sets a limit to the individual array size.
When the shadow each other like leaves on a tree, or trees in a forest, then the efficiency falls significantly.
A big problem with these very large solar farms, is that the arrays of panels have to be spaced apart so that no panel ever shadows another at any tiome of the day or year. It is easy to show that you never get better collection efficiency, than simply laying the panels flat, and covering ALL of the available land area that way. Of course, that requires more solar cells, so it is not necessarily the lowest cost approach. Well it likely is, if they apply taxes on the land area, the same way they would if you grew corn on it, or used it for any other kind of business.
Solar cell farmers, are living in a dream world, if they think their land use shouldn’t be taxed just like any other land use is. Which is not to say, I am in favor of land use taxes; I’m not, but if you are going to charge real estate taxes on land used for a garage, or hamburger joint; then the same taxes should apply to solar cell farms. But I’d rather see the taxes eliminated, and let people use their land for what they want.
But back to our seventh grader; keep thinking and tinkering young fellow;you’ll go far someday.
Solar engineering so simple, a 13yr old could do it.
When the aliens see the widespread application of this level of technology, they’ll know they’re messin’ with the wrong folks, and they’ll head for the hills! (invisibly, of course)
Now, the not-invented-here folks will surely be blasting this kid’s research, since he’s a) not affiliated with their university, and b) he’s not a solar scientist. I fully expect the Team to discredit him promptly over at RealClimate, for those, and other reasons. No grant money in it for ’em.
…but for me? Aidan Dwyer? YOU DA MAN!!
–the only downside to this is coming up with efficient manufacturing and installation. Maybe someone will figure out a way to “grow” the panels, as in stereo lithography?
George E. Smith
August 19, 2011 at 10:44 am
Thanks George, you answered some questions I was pondering.
George E. Smith: “It is easy to show that you never get better collection efficiency, than simply laying the panels flat, and covering ALL of the available land area that way. ”
I have a cruising sailboat where the only source of electricity to charge the batteries is from solar cells. Currently, I have mounted them flat, but have always wondered if there was a more optimal configuration. When attached to the mooring, the sailboat is constantly changing directions as the wind shifts. A tracking solar array would not work and physical simplicity is required.
This kid did get me wondering about a 3-D spiral mounted around the mast when not actively sailing.
Friends of mine. solar in parallel. pretty cool.
http://eiqenergy.com/
http://eiqenergy.com/parallel_solar/index.php
Two things –
1) This experiment has a lot of potential issues with it that people more experienced in engineering, electronics, and solar voltaics can (and have) pointed out.
2) Aidan Dwyer was 13 YEARS OLD and put this together!!! This absolutely ROCKS!! Aidan, I hope you get into engineering of some sort and start developing he kick-ass inventions that are going to blow our minds for the next 30 years! Keep on keeping on!
Seriously, if Aidan came to me, I would put some money to help him further develop and test this concept. If it pans out and we could do some business planning and development, I would invest in him to help him start a company to create and market these solar panel trees. They wouldn’t become solutions to the nation’s energy needs, but I bet that they could catch on in smaller, individual markets for those who want solar power but don’t want (or can’t fit) traditional solar panels.
Mega kudos to Aidan!!
There is an optimal angle for fixed arrays, such as this, in order to collect maximum energy – it obviously orients the solar panel such that it receives the most intense solar radiation during
the day. Any other angle collects less energy, therefore unless all of the panels are oriented
at the optimal angle, the energy harvest of the array will of necessity be less. The panels should be pointed due south. For an array of unchanging elevation, max yearly harvest obtained with an
elevation angle equal to 90 degrees minus one’s latitude. Changing elevation to match the Sun’s path doesn’t result is greatly increased harvest. Certainly nowhere near 30%. Perhaps 10%.
Trying to orient panels in the fashion shown here would result in extremely complicated mounting
apparatus and would be unsuitable for roof mounting, by far the most common method.
ideally what you would do is minaturize the cells and put them on a flexible substrate in the shape of leaves, no more ugly solar. hehe.
Color me skeptical. I find it very difficult to believe that the same number of solar cells mounted on a solar tracking system would not provide much more energy. Maybe compared to a fixed mounting system he can improve efficiency, although I doubt even that.
As others have noted Volts ain’t Power…
Obvious nonsense, for many reasons listed above. The kid does write surprisingly well, though, better than most adults. On the other hand, I’ll bet he doesn’t write better than his parents.
http://www.amnh.org/nationalcenter/youngnaturalistawards/2011/aidan.html
FAIL!
On the comments about the tree having more panels than the house…
Looking closely at the tree, it appears to have a total of 20 panels.
One poster has already surmised the house had 10 panels on the other-side of its roof for a total of 20. Which would then match the total number on the tree. Thus, no discrepancy in the numbers.
However, having solar panels on a roof facing away from the sun, is a whole different matter as to the validity of the results. Additionally, as others have very correctly pointed out, measured voltage without a load does not indicate the amount of power produced.
Warmista: “Was this research peer reviewed?”
Sceptic: “Why, yes it was! By 13 year olds, just like the UN-IPCC reports!”
Kuddos to this Kiddoo!
A simple hypothesis was tested by a simple experiment and the data and analysis were openly published.for critique and replication. The experimental data showed real promise and the hypothesis deserves further, more detailed testing to determine maximum feasibility and limitations. Well Done, Young Man!
I sure hope Aidan Dwyer chooses engineering as his primary career interest! We need lots more like him, out here in the engineering world…..
Oh, COME ON!! Click the FREAKIN’ LINK!!!!!
“I used PV solar panels hooked up in series that produced up to 1/2 volt, so the peak output of the model was 5 volts.”
This statement would indicate only 10 panels for the simulated tree.
Unfortunately, many solar panels do not work if all of them are not gaining energy. Shadows can kill. The shadowed units may become where the collected energy goes rather than to the system. It may have a lot to do with the wiring, also, and this may have been improved. On larger panels, a hand held over it can be enough to significantly interfere with performance.
George E Smith;
‘So deliberately building an array of solar cells, that are quite non-uniformly irradiated, is really a non starter. It is ok to have differnt illumination on different arrays; but ONLY if they are series connected. For any single array in a series stack, non-uniform irradiation sets a limit to the individual array size.’
Not if micro-inverters are used. In which case it doesnt matter if there is different illumination.