Cooking with Solar

[ohdrinkboy]

What are your solar cooking experiences?

Was just looking at this for some quick hot water....they say 20 min to boiling.
Baby Thermo 2 Cup

[callmecrazy]

That would probably work well today, with it being 100 degress outside. But, I'd be really surprised if it didn't take 6+ hours to heat water for tea with that design. Not enough surface/collection area....

Of course my experience is limited to reading about solar cooking, and watching videos of people using 30 square feet of reflective surface to cook a 4qt pot of soup over a span of 8 hours.

[Bruce626]

Considering that I am in a third world tropical country ten degrees north of the equator, one would think that solar cooking - especially in a poor country - would be something that one would occasionally see. In seven years, despite keeping an eye out for such, I have not seen any solar ovens on offer anywhere here (Philippines). $65 USD to boil two cups of water seems a tad steep even if it works as advertized. There is a site on the internet done by a Swiss outfit that indicates that clear water with dubious organic microbes can be pasteurized with six hours in the sun. They use a recycled clear plastic two liter bottle (soft drink) sitting on a reflective surface. If heat is the object, one might drop in a black anodized aluminum tube to help absorbtion, and possibly put inside another clear container to reduce heat loss due to convection. One often reads about initiatives to assist the poor by teaching about using free solar isolation to pastuerize, heat water for bathing, and/or cook - but one seldom to never actually sees such (with the possible exception of first world yachties using a solar shower water bag).

[callmecrazy]

It might actually work as described.

SOLAR DISTILLED WATER FRESNEL LENS WATER FILTRATION SYSTEM CLEAN DRINKING WATER Solar Distiller. - YouTube

[Bruce626]

Nice video. One can often scrounge a Fresnel lens off the front of a rear projection TV that is being discarded, I was toying with such a system to make a solar powered forge some years ago. As one can see from the setup, this is not likely something that is easily used on a boat - even a relatively stable catamaran with lots of top deck space (and, as demonstrated, the fire hazard is not to be underestimated).

Note that there are some nice designs for relatively low temperature flat plate solar stills more easily used on a boat - "Sailing the Farm" might have directions for making one if I remember correctly. A low technology and inexpensive watermaker from the past, largely superseded by high pressure reverse osmosis technology. Won't make a cup of hot tea though.

To get tea from the sun, one can just make 'sun tea' - a clear closed container containing potable water and some tea bags left in the sun to steep and left out after dark to cool (or perhaps immersed a couple of meters below the surface where the sea temperature is cooler). The slow steeping process leaves the tea without the often bitter tang obtained with boiling water when the bags are left in too long.