• And on the hardware side, the Giant Solar Funnel is live

    by  • June 14, 2009 • Hexayurt • 3 Comments

    Solar funnel from Jonathan Sanderson on Vimeo.

    Thank’s so much to Jonathan Sanderson and Elin for making the film. The Giant Solar Funnel is a solar funnel solar cooker than is very powerful, safe, and can be made in a few minutes from a big sheet of cardboard or corrugated plastic using just tape, glue and tinfoil.

    Give it a try, let me know your results!

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    Vinay Gupta is a consultant on disaster relief and risk management.


    3 Responses to And on the hardware side, the Giant Solar Funnel is live

    1. William Wiltschko
      June 15, 2009 at 4:57 pm

      Solar Cookers International (www.solarcookers.org) has been doing this for decades. How is this different or better? Is your distribution better? Just asking…


    2. RJ
      June 29, 2009 at 8:41 am

      Vinay you made two critical errors in its construction hence the lacklustre results. You forgot to cut a semi circle out of the edge of one of the long sides. Then you fold on the semi circle giving a tighter angle of incidence. The best angle is a between 50 to 60 degrees. The result of what you have done is that the bulk of the reflected rays are bouncing out of the funnel because the funnel’s angle is too wide.The funnel concentrates like a periscope not a parabola! Secondly, you used the wrong side of the aluminium foil,the matt finish side gives a far better result because it reflects less and absorbs more IR!

    3. June 29, 2009 at 10:20 am

      William, it’s a different design which looks like it might be easier to manufacture and give higher cooking performance, but we won’t know until it’s had some serious testing and field trials.

      RJ, the solar funnel wants to be as reflective as possible to concentrate the power at the bottom of the funnel, rather than absorbing heat further up. If we wanted a matt surface we could just use plastic 😉

      On the cone angle, I think the optimal angle is about 45 degrees which is a bit narrower than the inventors suggest. Again, a topic of active research. Where did you get the 50 to 60 degrees figures?

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