How does solar cooking work?

A solar cooker lets the UV light rays in and then converts them to longer infrared light rays that cannot escape. Infrared radiation has the right energy to make the water, fat and protein molecules in food vibrate vigorously and heat up.

It is not the sun’s heat that cooks the food, nor is it the outside ambient temperature, though this can somewhat affect the rate or time required to cook, but rather it is the suns rays that are converted to heat energy that cook the food; and this heat energy is then retained by the pot and the food by the means of a covering or lid.

This occurs in much the same way that a greenhouse retains heat or a car with its windows rolled up. An effective solar cooker will use the energy of the sun to heat a cooking vessel and efficiently retain the energy (heat) for maximum cooking effectiveness.

How solar cooking works can best be explained through the following mental diagramming of the process as well as the above images.

...For maximum efficiency it is necessary to "track" the sun, or in other words adjust your solar cooker so that it is directly towards the sun in order to be able to better concentrate and absorb the suns rays.

This does not mean that you must continually stand beside the solar cooker the whole cooking period. But it can mean adjusting the angle and direction every so often or every set period, such as every one to two hours.

The more direct that the sun's rays are towards the food and cooking pot the greater the energy (heat) capacity will be from the sun's converted rays.

Ideal cooking results when using a solar oven occur when the sun is bright and uninhibited or unimpeded by clouds, shadows etc.

Cooking can be accomplished as well on days when the clouds are high and thin, but it may slow things down a bit, and one would be wise to start a little earlier than usual.

Long, slow moderate solar cooking, such as with stew, chili, veggies etc. will do fine under less than bright skies if you allow more time.

Baking on the other hand will take longer and the temperatures will not be as optimum as could be, thus resulting in mixed outcomes with your baked goods.

How do the different parts of a solar cooker work

There are three main components to most solar cookers, or you could say three main principles to effective solar cooking; these being:

Concentration of the sun's rays is performed most often by reflecting panels, petals and such surfaces that can "focus" or concentrate the rays of light (UV) to a point or concentration.These reflecting panels are usually made of materials that are shiny and reflective due to the substance used in their manufacture, such as silver, chromium and aluminum.Without a means to concentrate the sun's rays it can take longer to heat objects or surfaces, thus most solar cookers are constructed with reflector panels to speed up the process of heat accumulation.

Absorption of the sun's energy (heat)in solar cooking is best achieved when a surface is dark in color, thus the most common solar oven interiors are usually black in color as well as the color of the cookware used for cooking the food.

Dark colors absorb the heat, whereas light colors do not absorb heat well. And some colors can reflect the sun's energy away, such as silver for example. Generally, the best cookware for solar cooking is the dark, thin variety because it absorbs the heat (energy) well; and because it is thin, it can then transfer the heat more quickly and evenly to the food.

Retention is the final principle in solar cooking.If a solar cooker is not well insulated and if it does not have a cover, or lid, then all of the concentrated heat (energy) and all of the absorbed heat would quickly dissipate into the air and be lost to the surrounding environment. A solar cooker must have the means to "trap" or hold the concentrated heat allowing it to accumulate and to "build up" to sufficiently high enough levels to be able to effectively cook.

* * A fourth principle, though not vital in all forms of solar cooking (parabolic cooking is one) is: transparency of your retentive materials, or in other words, your lid on a solar oven or your enclosure around your pot/pan on a solar panel cooker needs to be able to allow the sun's rays to penetrate inside to where the food/cooking vessels are located. This ability of the sun to penetrate is usually achieved by using clear glass, or plastic coverings on a solar cooker lid/door/enclosure which then in turn acts as an inhibitor, trapping the heat as well.

Got a Question about Solar Cooking?

What would you most like to know?

How might we answer your Solar Cooking Question?
Submit your question and we will do our best to answer it for you.

Enter a Title for your Question

Click here to see the rest of the form and complete your submission.

What Other Visitors Have Asked

Click below to see Questions from other visitors to this page...

Safety for solar cooking
Is it safe to use magnifying glass in solar cooking ?

All glass solar cooker
My question is if you can make a full glass solar oven with reflective panels on the side? Will this work?

Boiling water
Which type of solar cooking is best for just boiling water?

Are there any chain stores that sell solar cookers?
Are there any chain stores that sell solar cookers along with instructions for their use?

What about splatterings from cooking spilling al over the mirrors?
I never see solar cookers myself but I wonder about the chore of cleaning after cooking if any?

What kind of materials best absorb heat from the solar cooker?
From these items what will be the material that can absorb the most heat? Ex. empty cardboard box with its lid, scissors, aluminum foil, tape, plastic …

thermal energy
how will thermal enrgery enter the solar cooker and becume trapped inside email me at ashley.luna @tauntonschool.net

What other insulators can I use for my solar oven?
I know you can put rolls of newspaper in the solar oven, any other cheap insulators like cotton balls or something?

radiation
what type of radiation passes through the box?

use of a conductor in transferring heat from a solar panel to a solar cooker
I am trying to make a solar cooker and the main challenge is how to transfer heat from the sun to the cooker

Application of Solar Cooking for Cooking Mid-Day -Meal in Schools
We want to start the technique of Solar Cooking in running mid-day-meal in schools. On trial basis we want to start in school having 50 odd students. Our …

at what angle should the mirror be placed in a cuboid shaped solar cooker to get maximum reflection focused at a point
i need this information for a science project

why would you use plexiglass instead of saran wrap?
Why? Also which one is better? _____________________________________________ Thank you for your question Jolee, One can use saran wrap for …

What degrees of the panel should we put to make the solar panel reflect heat efficiently?
Should it be 120???????????? Your answer could work, depending on the size of your solar oven and the size of your panels. Here is some advice …

why we use solar cooker ?
We use solar cooker because it is the cheapest source to cook food. ___________________________________________ Thank you Vaibhaw Nand for your …

HELP! Solar oven problems.
My group is doing a solar oven for our graded assignment. So far we wasted three days making two useless prototypes that cooled down the water that we …

Minimum ambient temperature?
Is there a minimum ambient temperature needed to allow a solar oven work? If so, what is it? We are conducting a science experiment to determine if …

Which interior is better for the inside of theSolar Oven?
I built a solar oven 24 by 15 by 8 in. outside measurement and 22 by 13 by 8 in. inside measurement. I have 1/2 in. thick tempered glass that rests on …

Solar Cooker Temperature
What is a "good average" maximum temperature for a solar box oven. I have students building ovens for a project and I need a temperature that they should …

Building a Solar Oven
I am building a solar oven for a science class. The materials we are provided are as follows: Tin foil, cardboard, tinfoil tray, aluminum foil, saran wrap, …

solar cooker science project problems
I am making a solar oven for a science project, but we are not allowed to use plastic, glass, or plexiglass in our ovens. Are there any designs that do …

how or where should I place additional reflective panels for pizza oven?
My daughter is doing a science project and she is going to make 2 solar ovens. I suggested doing the simple pizza box style oven and then perhaps same …

What angles sre the side solar panels cut?
At what angles do you cut the 4 side panels for a box solar oven? Also at what angle do the solar panels sit to direct the suns rays to the box below to …

Anybody know about sun tracking devices?
I never built a solar cooker , but I assume that everyone has to move or adjust the solar cooker manually to align it toward the sun every 15 minutes or …

Click here to write your own.

Aluminum Roasting Pan Solar Cooker?
Hello, I have an antique roasting pan (a large turkey pan with removable grate on the bottom, and side lifters attached to the grate). It also has a …

What sizes of Granite Ware Pot will fit into the Sun Oven?
Or any other oven. Please recommend sizes - thanks! I am using my Sun Oven for the first time today and find the 9" round roaster to be too small. …

Uv rays
Can You use a uv flashlight and the sun to cook food?

Building a Simple Solar oven
I am building a simple solar oven for school that needs to get up to 150 degrees F, and I was wondering if you could give me a simple idea that I could …

How does a solar cooker trap heat?
Plastic covering? Greetings Cherie Ann, Thank you for your solar cooking question. A solar cooker does have to trap or retain heat in order …

what energy transformation takes place in a solar cooker
What energy transformation takes place in solar cooking?

How does the box solar cooker work ?
For my School's Science fair __________________________________________ Greetings Varun, Thank you for your question about solar box cookers. …

what are some of the designs of the solar cooker? Not rated yet
the designs _________________________________________________ Thanks for your question. Here on this you can see some different designs and …

how would heat gain and heat loss affect solar cookers Not rated yet
when building a box solar cooker and a solar panel cooker, how would heat gain and heat loss affect a solar cooker? Can anyone help me understand this? …

aluminum tinfoil? Not rated yet
I am a student who is trying to make a simple yet efficient solar oven, i got the absorption down but can i use aluminum tinfoil for concentration? …

How does solar energy affect cooking? Not rated yet
Hello My daughter has a project and she has to do a pizza box solar oven. My question is how does solar energy affect cooking? Thank u in advanced …

Expensive solar cookers Not rated yet
hi my name is Sinead, i am doing an assignment about solar cookers in third world countries, your web sight says that basic ones are only $5.00 which …

reflective surfaces Not rated yet
Does the number of reflective surfaces that a solar oven has make a difference in how fast or how hot water heats up?? _____________________________________________ …

Cost of materials Not rated yet
Hi I'm doing a project for environmental science and I was wondering how much materials would cost for solar cookers to send to under developed countries. …

how to make the best solar cooker in the class? Not rated yet
I am in grade 10 science and I have a project to make a solar cooker that will heat up at least 10 degrees when tested; the more degrees the more bonus …

material used for solar cookers Not rated yet
If we want to make a model of solar cooker ,what material we have to get from market and for what purpose. _____________________________________________ …

Materials to use for solar cookers Not rated yet
what kind of materials are used to make a solar cooker to ensure optimum performance? Thank you Limakatso for your inquiry. That is a very good …

Click here to write your own.

Your Name	(first or full name)
Your Location	(e.g., City, State, Country)