Solar power from hair?

Now this is an intriguing concept, but don’t start saving your shavings just yet…

A new type of solar panel using human hair could provide the world with cheap, green electricity, believes its teenage inventor.
Milan Karki, 18, who comes from a village in rural Nepal, believes he has found the solution to the developing world’s energy needs.
The young inventor says hair is easy to use as a conductor in solar panels and could revolutionise renewable energy.

The solar panel, which produces 9 V (18 W) of energy, costs around £23 to make from raw materials.

This is early. As far as I can tell, the Daily Mail is the only source for this breakthrough, so our information is limited. From what we have though, here are some thoughts (coming from someone who is, alas, not an expert in hair…):

– More details are definitely needed. It says it generates 18W of electricity, but W/m^2 is the number I’m interested in. It’s hard to tell from the pictures, but I assumed it was 2ft X 2ft. That’s equivalent to about 50 W/m^2, which is pretty decent.

– But even that number’s worthless, because we need to know what conditions it was used. What’s the solar radiance? I think solar panel efficiency (W/m^2 electricity over W/m^2 solar radiance) is more important over the range of expected solar radiances, but I’m not sure. And we have no idea what that was. Did he just shine a light on it to get that value, or did it come from the Sun? Nepal’s at about 30 degrees latitude, which should give it a pretty high solar radiance (don’t know about cloud cover though). So this might be a bit on the low end. Not bad for a first try though.

– 23 pounds per panel works out to ~2.20/W. I just read recently that solar panel prices are down to $1.80/W. So this isn’t necessarily a deal breaker. Then again, prices are probably so low because of the recession and overproduction, not because costs are that low. In any case, this means the payback period (not counting installation and everything) is ~3-5 years. That’s pretty decent. But if the hair needs replacing every few months, then the payback period may never happen.

– Yes, he said costs could be cut in half if mass produced, but I don’t see any way of that happening. Mass collection of hair? Where are you going to get it all? I doubt even New York City could produce enough hair to get a mass production plant.

– Apparantly it works due to the melanin in the hair. So does that mean that gray or blonde hair isn’t as good? Will barbers start charging different amounts for each hair color? We can be racist AND ageist! Sorry, I had to put that one in there…

– Most importantly of all; this is described as a school project. There appears to be little thought at this point into the details of commercialization. So practically everything at this point is speculation. By everything, I mean costs AND benefits. Maybe they can boost the efficiency with more research. But the costs are probably more than this kid predicts. And there may be other issues as well.

– What about rain, weather, animals, etc? The article does say the hair must be replaced every couple months, so that’s an issue right there. Needless to say, nobody here will do it.

Pretty innovative approach though. My guess is that if it works, it has more of an application for undeveloped countries than for us. There’s no chance we can produce enough hair to satiate even a tiny fraction of our electricity demands, but it would certainly help out in Nepal. Also, even though this is early, I highly doubt hair is as efficient as cells specifically designed to be photovoltaic, and so I doubt they’ll be able to compete in the W/m^2 range. And for countries that use a lot of energy, that’s a deal killer.

Hopefully this kid finds a path to commercialization. I wouldn’t mind hearing more about it.


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