Tips and Tutorials

How Does a Solar Cooker Work?

Solar Cooker
Written by Shikha Mehta

Did you know you can save on your cooking fuel bill if you buy a solar cooker? Solar energy is replacing all conventional sources of energy. You’re more aware of solar power that provides electricity. However, another way of tapping it heats water and makes meals.

Normally, a kitchen has a cooking gas that uses LPG gas or kerosene to burn. Moreover, there is an oven to bake dishes that run on electricity. Solar cookers actually replace both! You can boil, fry, pan-fry, roast and bake food in these devices. You can also pasteurize drinks!

I’m sure you’re willing to try this out. There are many varieties in the market having different technologies and prices. Let’s check out everything you need to know about solar cookers.

What is a Solar Cooker?

Just like solar water heaters, this device traps sunlight in a way that heats food or drinks. They mostly look like a box or a dish where there’s enough space for a vessel.

No additional fuel is used here. The device is designed to trap sunlight within and increase the temperature inside between 65°C (150°F) – 400°C (750°F). Let’s see how.

How Does a Solar Cooker Work?

There’s basic science involved behind the working of a solar cooker:

  • The cooker is made of a material that reflects light, like thin metal or mirrors.
  • All the light concentrates at one point.
  • At this point, you keep the vessel containing food or liquid.
  • Sunlight has particles that are high in energy called photons.
  • When these photons interact with matter, the molecules start vibrating.
  • This vibration generates heat.
  • When you cover the vessel with a glass or plastic lid, it traps this heat inside. At last, your meal ready to consume.

Depending on the design, each cooker has its own pros and cons. So, let’s take a look at the options available.

Types of Solar Cooker and Their Uses

There are 5 types of solar cookers by design and functionality:

Panel Solar Cooker

Imagine if you’re camping in the mountains and you have to cook your own food- all by yourself. Here’s when a panel cooker assists you. You can fit this device in your backpack and cook yourself meals during the day. You can get it for as less as $3!

Design: The cooker is made of cardboard and aluminum sheets that reflect light at one point. The top and one side of the cooker is open. Since it’s made of cardboard, you can fold it easily.

Capacity: 121°C (250°F) – 149°C (300°F)

Utility: Boiling soup & vegetables, cook meat and bake desserts

Box Solar Oven or Solar Stove

Imagine if your oven could bake without you having to plug or start it! Well, the opportunity is available in the market already! You do get ovens that you can place in the sun to make you a filling meal. No need for plugs!

Design: It is a closed box, usually black in color. It has a transparent lid that allows sunlight to enter while the rest of the walls help to trap heat.

Capacity: 121°C (250°F) – 204°C (400°F)

Utility: Bake bread, stew & desserts as well as heat liquids

Parabolic Dish Solar Cooker

Just as a parabolic dish CSP, this one functions in the same way. This is one of the most efficient solar cookers that exist in the market to date.

Design: The cooker is in the form of a dish, made of a mirror or any other reflective material. The light concentrates on the focal point. This generates immense heat. You can cover the vessel containing the item with glass or plastic to trap more heat.

Capacity: 260°C (500°F) – 371°C (700°F)

Utility: Grilling, frying, stir-frying and boiling various dishes

Evacuated Tube Cooker

You’ve most probably studied in physics that light travels the fastest in a vacuum. The cooker uses this concept to heat food faster.

Design: The tube is made of glass which is a vacuum from the inside. So, light passes through the tube quickly. Since the material is glass, it retains it well, heating up the entire tube.

Capacity: 290°C (550°F) or above

Utility: Bake desserts & bread and cook vegetable and meat

Community Solar Cooker or Solar Kitchen

While most solar cookers are capable of cooking for only 4-5 people in a day, there’s just one type used for the masses. This cooker can make food for more than 50 people at a time. This makes it useful for use by lower-income groups.

The shape is similar to a parabolic dish, though the way is bigger in size. One cooker covers an area of 7-9.5 square meters. They’re made of mirrors that reflect sunlight to the focal point. Some have secondary reflectors that enable indoor cooking too.

Benefits of Using a Solar Cooker

Often, people think that solar cookers have a limited capacity and are not as efficient as our regular ovens and stoves. However, you should know that with time, they have developed to function way better than what you have inside your kitchen. You can literally cook anything in a solar cooker – meat, bread, vegetables, stew and soups.

Following are the advantages of using a solar cooker:

Eco-friendly technology

We all know that the sun is a renewable source of energy, abundant and free for all. All you do is tap it the right way so that you can get the most out of it. No emissions or residue is left, unlike any other conventional source.

Free of cost

While you might have to pay to buy a solar cooker, you don’t have to pay for the fuel – the sun. Usually, your electricity bill includes charges for the stove and oven you use. However, you make a one-time payment for solar cookers.

Makes more nutritious food

You may say that solar ovens are slower than the microwave. However, the truth is that when food is cooked slowly, it is more nutritious. Moreover, the flavour and taste of the food is also more intense.

Saves time

Compared to cooking on a stove, cooking on solar ovens can actually save you time. This is because all you have to do is mix the ingredients, put them in a vessel and then put it in the cooker. In time, the food is ready.

Excellent for making dry food

All solar cookers are designed to trap moisture. Thus, if you want to make something dry, it is actually more effective than a traditional cooker, stove or oven.

A good tool for beginners

If you want to learn or teach cooking, using a solar oven helps greatly. This is simply because they are extremely simple to use. You can easily use it for complicated items that need more expertise on a traditional stove.

Safer to use as compared to a traditional stove

Usually, when you cook on a gas or electric stove, you need to stir the food continuously. This has higher chances of getting your fingers or hands burnt. However, the only time you have to be careful with the solar cooker is when you take the food out.

The Best Solar Cookers You Can Buy

Solar cookers are now easily available for online purchases at extremely reasonable prices. Considering that they last a lot longer than electric stoves and ovens and do not have added fuel or maintenance costs, following are the solar appliances you can use for cooking:

GOSUN Survival Gear Solar Oven Sun Cooker

You can bake, roast or steam food at a temperature up to 550°F in 20-30 minutes. It works with the help of a vacuum tube and parabolic reflectors surrounding it. The best part is that it is portable and extremely safe to use.

Sunflair Portable Solar Oven Deluxe with Complete Cookware, Dehydrating Racks and Thermometer

This is another portable oven that is lightweight and excellent for baking anything. It is suitable to carry at picnics and camps. It can cook up to a temperature of 285°F taking 30-40 minutes. The best part is that you can fold it as it is made of a soft, heat-trapping material.

All American Sun Oven Dehydrating and Preparedness Accessory Package

This is a typical panel cooker that works at 360-400°F to bake, boil or steam anything you want. It is foldable and easy to set-up. Thus, you can carry it wherever you want to. However, the best part is that it takes only 20 minutes to cook anything.

How to Make Your Own Solar Cooker: DIY?

Well, solar cookers aren’t that expensive, if you see that they don’t require any maintenance costs. Still, you can choose to make, especially if you’re only traveling.

You’ll be needing a box, black paint, cardboard, foil, scissors, glue, plastic sheet, and plastic lid.

  • Cut out the top portion and paint the inner walls black.
  • Cover the outer walls with plastic.
  • Cut the cardboard in the form of a trapezium and stick foil on one side.
  • The smaller width should be the same as the length of the box.
  • The larger width will be 2” bigger.
  • Stick the trapezium over the box in a way that the foil reflects light inside the box.
  • Cover the top portion with the plastic lid.

You can create 1-4 reflectors, depending on your requirements. If you’re fond of making stuff and experimenting, this is a good thing to try out.

Since solar cookers work only in the presence of sunlight, you do need an alternative stove that works at night. However, you still save on your bills as you’ll make 2 out of 3 meals using the solar cooker.

Don’t have time for making stuff? Let’s check out this absolutely cheap solar stove you can buy for starting.

About the author

Shikha Mehta

I discovered my talent in writing while I was in high school. Since then, I discovered the joy of sharing your knowledge with people around you. This is the reason why I love making my contributions to Insights of Technology. Being a certified content writer, I have been writing on several topics, science & technology being one of my favorites.

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