Solar Ovens?

[islandpiper]

With REAL summer just around the corner I was wondering if any one here had done any SOLAR COOKING? Self made oven? Commercial unit? What sort of unit?

I plan to make a simple insulated box unit with glass front and some mirror reflectors. Still looking for the right design.

And, no, cooking grilled cheese sandwiches on the dashboard of the truck does not count.

piper

 

[jdupre']

Oh, good. That's all I need - something else bouncing around in my head. :roll: :?

Reflectors, eh? Insulation and glass and .........................mumble mumble mumble................................



:lol:

 

[Kayak Jack]

Save your time, Piper San and Joey; these are about as practical as a bicycle generator and a freezer combo. Yeah, under very certain circumstances they will boil a half cup of water. But you'll starve to death waiting to cook a meal, at least twice in a row.

For anywhere in the South, look for an oven that will run on humidity. THAT would be a winner. (Maybe one that will run on dried Boat Science?)

 

[Wannabe]

I don't know Jack,
Think about it for a minute. With a good Fresnel lense one could concentrate a lot of sunlight in a small space and the humidity would just help keep the meat moist. How much insulation would you use in your oven. Would you put it on a gimble connected to a clock drive to keep it orentated into the sun. There is a lot to think about here. Ler us not be so hasty as to dismiss this fine idea. Living through some of the summers we have had down here I am convinced that this Would work.
Continue on Piper
Bob

 

[Kayak Jack]

Think about it, Bob. How many solar ovens do you see for sale at Sears, LL Bean, Campmor, or in your shop?

 

[Bellybuster]

solar ovens do indeed work and even up here in our Cdn winters. I tried the one in this link and was able to hit 240 degrees F. (averaged) in the late spring.
The problem with them is practability, they are just not practicle. They are large to pack and need to be monitered for temp and angle throughout the cooking process which can be long depending on what is being cooked.
With a match, some firewood and a dutch oven I can cook more in less time and take up less space. (maybe not weight)
It was a fun project though, been there done that won't bother again.

here's the link to the project
http://www.re-energy.ca/pdf/solaroven.pdf

 

[islandpiper]

I finally got a chance to make a real simple solar reflector, just a 20-inch cube cardboard box and some aluminum foil. I used some grill paint to coat a coffee can and foiled the top and put my candy thermometer in it. It ran up to 250 Degrees in less than five minutes with two frozen Pilsbury Grands Flakey Biscuits in it. Just about that time my wife wanted to go shopping so I cranked the unit around to face the sun and off we went. We came back in a couple hours and the biscuits were cooked, and BROWN through to the centers. I wish i had a recording thermometer so I'd know just how hot it got in there. I'm convinced now that on a sunny southern day we could bake a meat loaf or soda bread or whatever.

I may be watching for a bigger box and figure out how to get the foil on smoother. If there was some mylar covered foam board that would really be the best answer.

Piper

 

[lil'moe]

How about some of the foilfaced insulation board used in housing construction? Smooth, lite weight, halfway rigid--it might work.

 

[islandpiper]

lil'moe, that would work great. Just need to find some large chunks of scrap.....part of building projects is getting the materials for free or nearly so. Also, this design depends on many narrow folds and i'm not sure that an insulating material about an inch thick could fit the bill. That's why i was leaning toward foam board, as it is about the same thickness as corrugated board.

I used a simple cooked flour paste to stick the foil down and that may have caused some of the hill and valleys. I might go looking for some spray on solvent based adhesive.

piper

 

[jdupre']

250 degrees ?! Heck, way overcooked meat has an internal temp of less than 200 degrees. Water boils at 212 so there's a world of possibilites there. Other than a longer cooking time, I'd say it's an efficient cooking system -no real "fuel" used. Might be used as a slow cooker for stews or cooking tough cuts of meat while the campfire or kitchen stove is used for other things.

This reminds me of something I saw in college in the early 70's. There was a demonstration set up in the quadrangle by the science club. I don't remember all the details but I remember an umbrella shaped dish with a reflective coating on the concave side which was facing the sun . In the middle of the dish about 6 inches from the surface, was some kind of motor. I remember seeing a clear cylinder and a piston going up and down turning a crank. I'm guessing this motor was turning a few hundred RPM. Circular motion with no fuel burnt. That should bear greater investigation. Never saw anything like it since. Interesting idea.

Joey

 

[Jimmy W]

That was probably a solar powered Sterling engine. http://en.wikipedia.org/wiki/Stirling_engine
YouTube has quite a few videos of them. A short one here: http://www.youtube.com/watch?v=nq6iCO9KLKA&feature=related

 

[jdupre']

Jimmy, the You Tube video is just about exactly what I saw. Can you imagine scaling that up 10 or even 100 times. You could be talking about some real serious power.

Joey

 

[Kayak Jack]

I hope you guys don't mind if I stick to my camp stove.

 

[jdupre']

Go ahead and keep using your camp stove. I'll keep using my grill and alcohol stove. Piper will probably (hopefully!!!) keep using his Dutch oven. The solar oven might be something one would use in ADDITION to and not INSTEAD OF your normal cooking system. For dyed-in-the-wool tinkerers, things like solar cookers and soda can popcorn poppers are itches that have to be scratched. In the DNA , I guess. :mrgreen:

 

[Kayak Jack]

<SNIP> For dyed-in-the-wool tinkerers, things like solar cookers and soda can popcorn poppers are itches that have to be scratched. In the DNA , I guess. :mrgreen:

At least, it serves to keeps you unruly kids off the streets. sigh

 

[oldsparkey]

Folks use to think that the automobile would never replace the horse. :roll: Solar energy is like the automobile was back then. 10 years from now things should be interesting when looking back to these days.

If someone would of told me about all the wonders we have today back in the 50's I would of thought they were crazy Science Fiction Nut's. Today we take all that progress for granted.

 

[Kayak Jack]

<SNIP> If someone would of told me about all the wonders we have today back in the 50's I would of thought they were crazy Science Fiction Nut's. Today we take all that progress for granted.

Science fiction has a sneaky habit of becoming science fact. Best example is, the patent office credits Jules Verne with invention of the submarine - "20,000 Leagues Under the Sea".

Other ones are Dick Tracy's wrist radio, everything that Buck Rogers had or did, etc.

I was talking with a friend the other day, who informed me that "mikes" are a thing of the future. It stands for Micro Devices. Solar panels are becoming easier to use, and more successful. The trick is to control the output. Hooked to a battery, a solar panel will continue to charge the battery to a point of ruination, and maybe explosion. Current has to be controlled. Operating satellite phones, laptop computers, GPS, iPods, etc. can now be done with solar panels, but they are not economically feasible yet to be readily available at Sear, Lowes, Home Depot, etc. Soon, very soon, we will have such solar panels in the crown and or brims of hats - or the yoke of a shirt - to power these devices.

The Ruptured Duck sez, The future just ain't what it used to be.

 

[Bellybuster]

solar power can easily be used as a sole source if it weren't for the cost. The cost will remain high untill the gas companies are running out of profits (not in my lifetime)
We priced out gouing full solar on a home and it was crazy expensive. To run fully off grid would have taken 35 years to break even but wow...is a gas furnace ever cheap

 

[islandpiper]

Here is the site that I found with the easiest/best unit:

http://www.freewebs.com/sunnycooker/fun ... erplan.htm

piper

 

[islandpiper]

The news is predicting that the Resident will propose broad sweeping alternative energy programs tonight to help kill off the oil industry. I think I may apply for the biggest SOLAR HEATING AND COOKING grant they offer. May as well get a hatful of money, as i already have built and used a prototype device and reported the results publicly. That ought to be worth a million bucks or so.

piper