DIY Solar Panels


Reader [unangst] pointed out to us an article in the U.K.’s Daily Mail, where a teenager from Nepal had managed to create a 9v, 18W solar panel using human hair rather than the usual semiconductors (usually crystalline-silicon). The complex silicon in solar panels are what keep the prices out of reach of developing nations, and while there are a number of new technologies that are helping  bring down the cost, [Karki] managed to make his solar panel for only £23 (roughly $38). He also claims that when mass produced the price could drop substantially down to under $10 a panel, which would shatter the $1/watt sweet spot.

The melanin in hair acts as an organic-semiconductor, and while the hair does not have the longevity that silicon panels have (months rather than years), these panels can be made cheaply and serviced with little to no complex knowledge. Using melanin as an organic semiconductor seems to be a newer idea, because information seems hard to come by, but we managed to find a research paper from 2007 that explored the energy absorption attributes of melanin, as well as some good background info for the science types.

Research Paper (Warning: PDF)

So, Hack a Day readers, which one of you is going to make your home-brew solar panels first? Let us know when you do.

Thanks [unangst].

74 thoughts on “DIY Solar Panels

  1. Who says the panel in the photo is the whole thing? It could be that panle only generates .05 watts and they’ve got hundreds of em. Somewhere I read that they buy hair for 16p/KG. So if only a fraction of the 23quid goes on hair, that’s a heck of a lot of hair and probably a huge panel.

  2. Max,
    That’s a reasonable question, except that elsewhere on the web there’s video of the team lighting devices that would require more than 0.05W, and there’s a photo of 1 panel providing about 9VDC and, apparently, lighting a fluorescent light via an upconverter, and there are articles claiming the students built a panel (just one is mentioned) capable of charging a cellphone. Also, by my calculations, a panel or bank of panels built with this technology would require 14,400 square meters or a square 120 meters on a side. Furthermore, according to quotes in other articles, the teens say that the hair has to kept saturated with salt water to work. So that means, somebody would need to keep a huge bank of panels wet all day long, as I imagine they would dry out fast. Then, there’s the matter of the hair which, after all, is just protein decomposing in the wet environment. Maybe what you say is true or maybe somwthing was lost in the translation. The author of the Daily Mail piece says she just “saw the panel working”. She didn’t really examine it and, based on the article, doesn’t understand the science behind it at all. When somebody from a university sees it or they publish a paper/patent explaining their technology we’ll know for sure. Based on what’s been made public, it’s virtually certain that the students haven’t made a working solar panel from human hair.

  3. I too figured BS but figured, hey why not test. Took five minutes to grab hair samples from the fam…running the gambit from blonde/grey to dark brown. Needless to say the voltages measured were inconsistent and very, very low: 6mV to -8mV, when exposed to a 23W CFL…much more than the 6V tube light in the Daily Mail article. FWIW, lighter colored hair (less melamine) registered voltage at longer lengths than darker hair (more melamine). I think this is am important observation seeing that the photo in the article shows dark hair and short segments between contacts.

    So, why were my readings so low? First thought was meter sensitivity/accuracy. I think hack-a-day had a post on this not too long back from the dude that does the oscilloscope reviews. So, I grabbed my cheapo meter to compare and sure enough, I registered 50 to 90mV using it (interestly no negative voltages this time). Interestingly, the dark hair did consistently register higher than the lighter colored samples.

    So, there may be something to this but I don’t have the equipment to test it correctly. I still doubt their results though based on the photos shown or of the ultimate practicality of it. The hair has to be wet? What about mineral content in the water or the hair itself? Is the hair cleaned before use? I can already hear the jokes about the village being downstream from the dump we send our e-waste to be “recycled”.

  4. “I too figured BS but figured, hey why not test.”

    I measured hair and got zero volts under full sunlight and exposed to a UV light source. I also got no conductivity. That is, hair is a perfect insulator.

    I suggest that you try different fibers other than hair such as synthetic fibers (rayon, nylon, etc.) plant fibers (cotton swabs, silk fabric), and sample different colors as a control. Also, try other multiple light sources.

    Please describe your setup exactly or post a photo of it. How much hair did you use? How were the electrodes arranged? What light source and how close was it to the sample? I have a picture and description of the setup I used on my website:

    If I you describe your experiment and I can successfully replicate it, I will post the results. However, I expect that you’ll find by using control samples is that you are seeing noise, not a real electric current.

  5. I think that hackers have their own way of looking at the world. When I see “hair solar panel” my very first thought is “what makes it tick”? I immediately want to take the idea apart and find the mechanism behind it. It seems that sites promoting this story are just passing it on without asking fundamental questions. Same with the “tree electicity” business. I instantly think: What if you cut the tree down? Does it matter if the tree is standing or lying down? What if the tree is dead? What if you stick the electrodes in wet soil? What if you stick them in a fence post? What if you tape them to wet concrete? See what I mean? Instead of getting all excited about “trees generate electricity” my first question is “*how* do trees generate electricity”? In my mind, asking those kinds of analytical questions is the heart of science (and hacking).

  6. I have to admit this is a very creative twist on the meaning of “renewable energy”. I would like to see some actual numbers on output and reliability before I got too excited.

    I think that true do it your self solar panels will be brought a step closer when solar panel manufacturers begin to integrate micro inverters into every panel. Doing so provides maximum power point tracking (MPPT) at each panel and eliminates string inverter design complexities.

    This makes it much easier for weekend warriors to get their hands dirty and complete a large portion of the install themselves. Granted you still need a qualified electrician to connect you to the grid but you can save a good deal on labor with this approach. For more information check out this article:

  7. Solar Panel Savings Measurement Tool – The website allows us to check how much will we actually save by installing solar panels on our roof. To calculate the savings, the website considers the square feet area currently available to install solar panels, available sunlight and its intensity in every state (of USA), in each month of the year, and the energy (kWh) we are currently consuming

  8. For some reason, flagging this story as a hoax attracts red arrows, which is a shame.

    It is a hoax, of course. Hair is too efficient an insulator for this to work. Also, the surface area exposed to the sunlight isn’t anything like enough to generate power, even allowing for the questionable properties of melanin.

    If you were to climb into those photographs and dismantle the apparatus, you’d find a battery keeping the bulbs alight.

    Jeff Martin

  9. It is a hoax, of course. Hair is too efficient an insulator for this to work. Also, the surface area exposed to the sunlight isn’t anything like enough to generate power, even allowing for the questionable properties of melanin.DIY solar panels are very useful in our lives thanks for the modern technology….Hmmm who invented the DIY SOLAR PANELS?

  10. Wow, this really is a hoax? Huh, it got me all excited about how it would actually work.. Haha. Weird though.. but anyways.. I suppose we can always just get one of those DIY solar kits and get cranking on our own solar cell power! (That’s what I’m doing, at least..)

  11. Thank you for your article. It makes a change to read an article that actually means something connected to solar power. I’ve got a similar website myself, so will keep popping back to see what else you’ve posted.

  12. Don’t bother reading any of the DIY solar panel articles that spammers post here. Instead, read this site that debunks their nonsense:

    The debunking link describes how spammers actually get coached on posting innocent-looking stuff on blogs like “Wow! This is really a hoax! I am soooo disappointed. Guess I will have to build my own DIY solar panel!”. And of course there’s a link to the spammer’s website.

    You can pretty much assume any post with “DIY solar” or “build your own solar panels” is a scam. Given economies of scale and other factors, you are better off getting commercial panels than getting mixed up with these bozos.

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