Here in the desert there is one of the best cookers around, the blazing sun. Does the best job on barbecue ribs by far, even better than the Satisfied Frog and our other fine local restaurants. Comes out more moist, falling off the bone. Sun's got its drawbacks. Doesn't work at night and not too good on cloudy days.
Solar cooking is slow, but moist and tenderizing.
Takes all day and you've got to realign the oven to the sun every hour or so as you walk by. Temperatures in our oven run 295 F degrees midday and down to 200 degrees or so by evening. It's best to use darker colored dishes or roasters to better absorb the sun's rays. If the food has a lot of moisture, use a covered dish to keep from steaming the oven window. If the window steams because the food is boiling you may need to lift the lid momentarily and perhaps wipe if necessary.