I took one look at the grill and knew they used a Fresnel lens! What surprised me was that the latent-heat storage of this BBQ. I didn’t know heat could at above 450 degrees F for up 25 hours!
I haven’t checked You Tube, but it won’t be long before the DIY version of this will be available. MIT may invented it, but I doubt this would not be hard or expensive to make. The only real challenge is making it pretty.
A Fresnel lens can be harvested for FREE off of rear-projection TV. Watch Freecycle and Craig List for FREE ones.
The following August 2011 article is from http://inhabitat.com/wilson-solar-grill-stores-the-suns-energy-for-nighttime-fuel-free-grilling:
….A group of MIT students are working with the technology to develop a prototype solar grill. Derek Ham, Eric Uva, and Theodora Vardouli are conducting a study through their multi-disciplinary course “iTeams,” short for “Innovation Teams”, to determine the interest in such a concept and then hopefully launch a business to manufacture and distribute these grills. The goal is to develop a business model for distributing solar grills to developing nations as well as a grill for the American market. The American version is expected to be a hybrid propane/solar model that will allow for flame cooking as well as through thermal convection. If all goes well, in a couple years we just be giving solar grills as presents on Father’s Day and enjoying sun-kissed instead of char-broiled even after the sun goes down….
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October 2012 update: I noticed this August 12, 2012 video is about welding with a Fresnel lens. What I found interesting is the heat storage ability of steel. I am guessing a solar grill has a steel plate for the heat sink. I have a couple Fresnels gleaned from TVs. Now I am on the hunt for a thick piece of steel (for FREE of course) so I can place my cook pot upon it. (In case your wondering, yes, I do think solar cooking is addictive. Well at least for me it is.)
Here is the welding video I just referred to: http://www.youtube.com/watch?v=u7VpnwVctOo&feature=relmfu.