Manny, I was shocked at some of the temps he was getting with those lens, he was talking about smelting copper!
That is truly amazing to me. I put an add on Freecycle for a projection TV, but its like a Taxi, when you really want one there are none around.
Graham, those folks are dedicated to solar cooking, they walk the walk as well as talking the talk.
Their set up are truly great, they had all the options working for them. Bottom line is, it is practical, it can be done, it does work, it saves energy, it saves money, it saves the planet, the draw back is that it takes more time to cook supper than we as Americans are used to taking. Oh, another draw back, it does not work in the rain,
Never doubt that a small group of dedicated people can change the world, indeed it is the only thing that ever has.