lundi 1 février 2010

Cheap solar panel using human hair

OS:Human Hair Solar Panel by Milan Karki

Milan Karki with his innovative solar panel made with human hair while a friend holds a light bulb above his head.(Credit: Tom Van Cakenberghe/Barcroft Me)

Milan Karki with his innovative solar panel made with human hair while a friend holds a light bulb above his head.
(Credit: Tom Van Cakenberghe/Barcroft Me)

Nepalese Teen Invents Cheap Solar Panel Using Human Hair

Adapted by Sterling D. Allan from a report in the UK's Daily Mail.

18-year old Inventor, Milan Karki, from rural Nepal, claims to have come up with a new type of solar panel that uses human hair, a design he thinks could provide the developing world with cheap, green electricity. He has built several prototypes. Once manufactured, he thinks these panels could be half the cost of the cheapest solar panels now available.

Inspired by Stephen Hawkings' discussion of ways to make static electricity from hair, Karki, theorizes that the Melanin (a play on his name?) in the hair enables it to act as a conductor, in place of expensive silicon. Melanin, a pigment that gives hair its colour, is light sensitive and also acts as a type of conductor.

His panel, which produces 18 Watts (9 volts at 2 amps), uses £23 in materials. The solar panel can charge a mobile phone or a pack of batteries capable of providing light all evening. Karki points out that half a kilo of hair can be bought for only 16p in Nepal and lasts a few months, whereas a pack of batteries would cost 50p and last a few nights; and that people can replace the hair easily themselves, so his solar panels need little servicing.




Official Website

none yet?

Response to Skeptics

The Engineers who originally commented on this story said it is a hoax, giving reasons such as the lack of sufficient surface area, and the general non-conductivity of hair. However, in a follow-up interview with the inventor, Milan Karki, Gizmag answers much of this criticism by getting additional information about the process. See their report published Oct. 15, 2009.

Here are some excerpts:

A circuit diagram of the Trinity solar cell. (Source: Gizmag)
A circuit diagram of the Trinity solar cell. (Source: Gizmag)
Karki appears to have based his innovation on a dye-sensitized solar cell rather than the more familiar layered silicon design. Karki was happy to share some details about his invention with Gizmag but was (naturally) somewhat guarded about full disclosure pending a patent application.
To create his cell he took a piece of glass, stained one end with some silicon dioxide to act as a cathode and fixed oxidized copper to the other (the anode). Human hair was soaked in organic salts and then stretched between the two connections and held in place. A thin layer of graphite covered the silicon end and the copper end left exposed to light (sunlight/UV). A few drops of iodine on the hair act as an electrolyte.
It's said to create electric current when light hits the oxidized copper end and knocks out some electrons which then travel down the salt-soaked hair to the silicon end. The function of the hair is not to soak up sunlight but to act as a bridge in the circuit to help electrical current flow, in other words as a conductor or semi-conductor.
Several of these cells are placed together in series and the power produced when exposed to sunlight is then used to charge a 12-pack of AA rechargeable batteries.
Of all the issues, probably the main one is that human hair does not conduct electricity. That hair can and does produce a static charge there is no doubt but as to whether it can conduct an electric current, all the evidence prior to this announcement clearly points to hair being an insulator rather than a conductor, such as the controlled experiments conducted by R A Fischer & Co in 1998.
Karki points to the porous quality of the cortex of human hair and told Gizmag that when pre-soaked in organic salts, the electrons flow through the hair assisted by the conductivity of the salts. He confirmed that while other porous materials had been not been investigated to see if there was a better and cheaper material available, numerous tests with varying colors of hair showed black hair to be the best promoter for those electrons. He attributes this to the higher levels of pigment found in dark hair.
And that leads to another point of contention. Melanin does indeed have electrical properties but as Hyatt points out: "as long as it's bound to the keratin in hair, it is insulated and doesn't come in contact with any electric charge. If there are any active melanin molecules present, they only act as a pigment or convert UV into heat which is how they protect your body from solar radiation." In order to conduct electricity the melanin would need to be "isolated from keratin and concentrated."
Karki says that the melanin merely acts to enhance the flow of electricity and it's the organic salts which actually do most of the work. In fact, he admits that once the hair dries out, the cell stops working but says that getting the cell operational again is a relatively simple matter.

Regarding the panels being show powering a light bulb in a fairly dark room, the Gizmag piece points out that the panels powered a battery which then powered the bulb. He also pointed out that the prototype used to produce the claimed 18 Watts was actually 6 x 5 feet, not the 2 x 1.5 feet shown in the photos typically shown.


Image:Hairsolar-panel Trinity.jpg
A close up of the solar cell created by the Trinity team - the dark hair can clearly be seen stretched between two metal pins. (Source: Gizmag)

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Image:Milan solar hair panel wires jp70.jpg
(Source: Daily Mail; UK)

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Image:Milan solar hair panel lighted jp70.jpg
(Source: Daily Mail; UK)




Company: (None yet?)

The Trinity International School science and technology team showing off the solar panel. (Source: Gizmag)

Inventor: Milan Karki

Milan Karki, 18, of rural Nepal attends school in the capital, Kathmandu. He and four classmates initially made the solar panel as an experiment but the teens are convinced it has wide applicability and commercial viability.

"First I wanted to provide electricity for my home, then my village. Now I am thinking for the whole world."

Raised in a village completely unconnected to electricity, Karki first tried to use water currents hydro power on a small scale, but said the experiment became too expensive.


In the News

  • Featured: Solar > Photovoltaics >
    Nepalese teen claims cheap solar panel using human hair - Milan Karki, 18, of rural Nepal, believes he has found the solution to the developing world's energy needs, saying hair (due to Melanin) is easy to use as a conductor, in place of expensive silicon. The £23 solar panel produces 18 Watts. Electrical engineers call it a hoax. (PESWiki; Sept. 10, 2009) (Comment)
  • Teenager invents cheap solar panel from human hair - The hair replaces silicon, a pricey component typically used in solar panels, and means the panels can be produced at a low cost for those with no access to power. (Slashdot; Sept. 9, 2009) [has some pretty insightful commentary]
  • Soylent, I mean solar, power is people!' - While the developed nations of the world spend huge amounts of money trying to eek out just a little more efficiency from traditional solar panels made from silicon, an industrious young lad from Nepal has figured out how to use human hair to get 9V of electricity from the sun. (CrunchGear; September 9, 2009)

Other Coverage


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See also

- Directory:Solar - index of resources
- PowerPedia:Solar Energy - Encyclopedic review of history and future
- News:Solar
- Directory:Solar Energy Research and Development
- Videos:Solar
- Directory:Concentrated Solar Power
- Directory:Solar PhotoVoltaics | Directory:Home Generation:Solar PV
- Directory:Solar Thermal
- Directory:Home Generation:Solar Heating
- Directory:Thin Film Solar
- Directory:Solar:Photosynthesis Imitation
- Directory:Solar Tower
- Directory:Floating Solar Chimney
- Directory:Space Based Solar Power
- Directory:Solar Sails
- Directory:Plastic Solar Cells
- Directory:Silicon - more efficient uses, alternatives, methods
- Directory:Black Silicon
- Directory:Synchronous Solar Heliostat
- Directory:Solar:Installation and Consultation
- Directory:Solar:Largest
- Directory:Solar Applications
- Directory:Solar:Chargers
- Directory:Solar:Vehicles
- Directory:Solar Hydrogen
- Directory:Walipini Underground Greenhouses
- OS:Solar Ethanol - distiller design
- Directory:Solar Pavement - black-body absorption of the asphalt - Other Open Source Projects
- PESWiki main index
- PES Network Inc.

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