Wow. Geek powers harnessed for good instead of evil. ;)

In the first pic, I thought I saw a mouse smoking!!!!! Aarrgghh! It's too early in the morning! hahaha

That is fabulous!

This made me smile because it reminded me so much of my son when he learned how to set fire to things with a magnifying glass. I'll have to share this with him when he reappears online from somewhere in the South Pacific.

Interesting.

How do you continually change the focus of that contraption to keep the sun focused in the center? Do you have to pick up the frame and keep moving it?

I use two solar ovens all the time - almost year-round. They are convenient, easy-to-use, most food cooks/bakes in a NORMAL time frame - although you CAN use them like a Crock-pot for slow cooking. I can easily reach temperatures between 350° and 400°F. I even bake yeast breads in them.

The open parabolic reflectors are more difficult to control the temperature. I keep my solar ovens on a cart on wheels so it's easy to turn to follow the sun and they are waist high for stirring or turning items being cooked. I also have the ovens tied down to the carts so the wind doesn't turn them over.

So-called "special" cookware is readily available and most of it is inexpensive, it needs to be dark and thin. I also use quart canning jars painted on the outside with black heat-resistant paint. The jars work well for heating water and cooking food. The Tulsi Hybrid Solar Oven came with an assortment of pans and I can make 4 things at once in this oven. The Sun Oven didn't come with any cookware and the cooking space is more limited.

The Tulsi is about the size of a small suitcase and is easy to pack with everything you need and is ready-to-go for you campers out there. It will also run on electricity, so you can cook/bake in it ANYTIME - day or night - using electricity, or use solar only when the sun is shinning.

Once you've invested in special pans (many I already had), they quickly pay for themselves by the energy you save using solar.

I suggest wearing dark glasses when working with ANY kind of solar cooker/oven, but especially homemade versions. You CAN burn your eyes if you aren't careful. A hat with a brim will also help shade your eyes when moving food in and out of a solar cooker.

In the homemade version shown in the picture above, you will find it handy to raise pans up off the ground by using a trivet or rings from canning jars. Most food will also cook better and quicker in this type of cooker if you place the pan in an Oven Bag (the kind you cook a turkey in) to help keep the temperature even and the steam from escaping. You can place an oven thermometer inside the oven bag to help make sure you are cooking at a food-safe temperature.

Quick tip... I bake SMALL whole potatoes in black socks (purchased new and used for potatoes only). Large potatoes don't work as well as small ones, and foil-wrapped potatoes don't bake well because the foil is reflective. If you use an open parabolic reflector, place the potato-filled socks in an oven bag.

-Grainlady

So....do you suppose that if I run down to the Theater and "borrow" a couple of fresnel lights, I could use them to "cook" with....even without the heavy duty light bulb?
So....how is a fresnel lens different from an ordinary magnifying glass?
Linda C

Thanks guys. It was a fun project to make with a few kids. I have a waiting list of friends who want to borrow it for their BBQ..

Caliloo, you don't have to move it much because the sun doesn't move that fast.

Grainlady, the Tulsi Hybrid Solar Oven is a different solar cooker than most. It is very well insulated and well constructed. The sun only give you about 200 BTU/sq ft. many inexpensive so called solar oven are not well made enough to keep the BTUs to buld up the temperature fast enough. The Fresnel cooker I am using is about 7 sq. ft. With a little luck, you can probably find an even larger fresnel lens.

Lindac, a fresnel lens is a magnifying glass of a different geometry. It uses concentric circles of progressively acute angle of refraction to focus light, allowing the lens to be flat in shape. Theater light fresnel lenses can be used if they are big enough to collect solar energy. They can be heavy because they are made of glass. The plastic ones are thin and light weight.

dcarch

That is so cool.

I use a solar oven for most of my cooking.
I cook everything from beans to french bread in it and it works great!