# Parabolic solar cooker



## Stephan1eMitchell (Jun 12, 2016)

Just curious as to whether anyone here has successfully turned a large old satellite dish into a solar cooker.

I have seen a few on YouTube but everyone I see there live in the south. I'm in Canada so I am hoping that a larger dish, perhaps 6 feet in diameter, would be enough for my climate. I also have access to a 10-foot dish, but I think that might be overkill.

I am hoping to find someone here who can point me in the right direction. Again, I have seen lots of examples on YouTube but I'd like to find someone who needed a larger dish and was able to get one working.

Thanks!


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## Mad Trapper (Feb 12, 2014)

You might also consider a frensel lens from a large dead TV set. Lots of info on those.......

https://offgridworld.com/build-a-fresnel-lens-solar-cooker-for-free/

http://prepforshtf.com/fresnel-lens-solar-cooker/

https://graywolfsurvival.com/84068/solar-diy-building-fresnel-solar-cooker/


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## Back Pack Hack (Sep 15, 2016)

I started to experiment with an old parking lot light I gutted. Just a big metal box with a glass door. Didn't get much done with it, then winter set in. Hopin' to get back on track with things go from white to green.

ETA: My goal is to just be able to pasteurize water, not cook food.


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## Elvis (Jun 22, 2018)

I've played with a solar oven, a friend used the Fresnel lens cooking. Sun powered cooking is very slow, especially when cooking something that makes a lot of steam plus it requires several hours of good sun. Both are sub prime for heating water and cooking a pot of rice compared to a wood fire or other cooking methods.

First understand that I've cooked using alternative methods for many years at least 30 times a year, mostly using the wood methods listed below. Yes, we use electric cooking much of the time but this house is solar powered so often cooking with electric isn't the best option.
Best is gas (propane in my case) grilling or close the top with a lid to make an oven, Rent or buy a 250+ gallon propane tank with a gas stove for several years of cooking.
Next is probably a rocket stove. a large handful of smaller wood and twigs will boil 2 quarts of water for 10 minutes and we make all sorts of things on the rocket stove. Just get a handful of large twigs for fuel..
Next is a wood fired dome oven to make everything from pizzas to bread to cooking a steak on a rack set on the coals.. Makes casseroles too.. delicious. 
Cooking on the woodstove in the house comes out last but better than cooking in a solar oven. 

One of my 1st preps was to buy a well known solar oven. Several years later I sold it. Just my 2 cents.


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## Mad Trapper (Feb 12, 2014)

I concur that wood is good except summer when it makes my house too warm.

My backup heat/oil furnace is off except when I need hot water for a shower in winter. The wood stove always has a large pan of water on it to humidify the house or for washing dishes. If I'm going to cook something a another pot goes on in advance, then I finish cooking on the electric stove. This is a big old boiler plate woodstove that takes 26" chunks of wood. You can use it for cooking on top, a dutch oven is handy.

Summer time lots get cooked outside using wood on a grill. Downside is when damm biting bugs are around but the smoke generated helps with those. Nothing better than meat/fish cooked smoked on good hardwood fire.


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## AquaHull (Jun 10, 2012)

parabolic interpolation

https://deepblue.lib.umich.edu/bitstream/handle/2027.42/29347/0000415.pdf?sequence=1

parabola

https://www.merriam-webster.com/dictionary/parabola

Automotive lighting FAQ - Headlamp systems

I did a fair amount of auto lighting, the parabola reflects light out, so an old tube TV lens may work


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## Stephan1eMitchell (Jun 12, 2016)

Elvis said:


> Sun powered cooking is very slow, especially when cooking something that makes a lot of steam plus it requires several hours of good sun. Both are sub prime for heating water and cooking a pot of rice compared to a wood fire or other cooking methods.


Thanks everyone for your replies and information.

Yes, that is the feedback I've gotten from most people about solar cooking. The little satellite dishes with polished finishes appear to work ok on YouTube but in the real world not many people seem happy with them. I didn't buy one of those solar cookers that you referred to, just because I thought there would be no way it would be feasible here in Canada.

That's why I'd like to try a large satellite dish - to see if casting the solar net a little wider will make it feasible. I'd like to try a 6-foot dish. I have access to a 10-foot dish but holy smokes that thing is BIG. I just wanna fry some eggs, I'm not lookin to burn a hole through my iron frying pan. But maybe here in this northern climate a super large dish may work the best. I am still hoping to find someone who has gone through this already. If not, I will report back to the group in 6 months or so when I am an expert on the subject. :^)


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## Mad Trapper (Feb 12, 2014)

The frensel lens from a dead tv will be easier and better.

Think about 2-4' of snow on a dish, and making the dish follow the sun, compared to a flat 4' X 3' screen. The screen you make vertical, what you going to do with a dish?

Also, look at making the focus are for a dish............


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## Elvis (Jun 22, 2018)

A drawback to a solar oven, whether it be an All-American solar over or a parabolic dish shining down and focusing the sun is that the ovens require a glass top to hold the heat in. Steam rising from the food clouds the glass reducing the solar heat getting in. A Fresnel lens has the same problem.

Now if instead you used that large parabolic dish to focus the heat on the bottom and sides of the "oven" box you would eliminate that problem. Basically instead of projecting the sun's heat through the glass top on to the food instead you heat the box itself like a real an oven works. It might work.

Keeping in mind that any solar oven only works when the sun is strong another way to cook with solar would be to put a couple of these 12v heating elements 
https://www.ebay.com/itm/152785819933
in a "oven box" Hook each one to a 100-150 watt 14-19v solar panel. By controlling the number of solar panels you'd have some ability to control the "oven" tempature. Add a bit of insulation to the box and they should be able to get the tempature up to 350 degrees. I never saw a solar oven get over 320 degrees.

No charge controller or inverted needed.

But add a $20 controller and a battery and you've got power to cook or run some lights even when there is no sun. The battery and controller part to store electricity are a bit more complicated to get right but not rocket science..


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## Back Pack Hack (Sep 15, 2016)

Elvis said:


> A drawback to a solar oven, whether it be an All-American solar over or a parabolic dish shining down and focusing the sun is that the ovens require a glass top to hold the heat in. Steam rising from the food clouds the glass reducing the solar heat getting in. A Fresnel lens has the same problem.......


That's why you cook using lids on the containers.


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## Yavanna (Aug 27, 2018)

Solar oven is something I always wanted to try, but the ones that seem to work are really expensive over here, wich is too bad, since I have a LOT of good sun all year long... Perhaps some day I will try to build one of those homemade versions.


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## Stephan1eMitchell (Jun 12, 2016)

Thanks again everyone for the input.

I thought about making a frensel lens but then I thought that in my climate it might catch enough sunlight to be useful. (My latitude is along the US-Canada border.) A 55 inch TV screen is 10 square feet of area. The model of satellite dish that I missed by a few days at my local scrap yard was 6'2" in diameter and would capture 30 square feet of sunlight. The 10 foot dish (almost 80 square feet!) I currently have access to would probably be too large to work with so I'm hoping that a 6 foot dish will work.

Also I should have been more clear when naming this thread. "Cooker" is a little vague. I want a solar stove top, not a solar oven. I want something to fry food on. I don't expect there to be much flour around in the Doomsday scenario I'm preparing for so I don't expect to be doing much baking. I want to be able to boil water, fry meat and boil a pot o' potatoes.

The SolSource solar cooker (I will attach a pic) has a diameter of 4 feet (12 square feet) but a YouTuber in a northern state said that it was a struggle to get it up to cooking temps. So I'm hoping to find a 6 foot dish and make it work.


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## Mad Trapper (Feb 12, 2014)

I think you are underestimating the frensel lens. If you find a good spot focus it can generate 2000 oF, that is enough to weld/melt steel.

It is also much easier to make a carriage to track the sun in comparison to a dish.


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## jmc (Mar 5, 2019)

And you can use the wonder bag to keep anything you've heated up warm.


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