Cardboard Solar Thermal Cooker

This project was made by Anthony Smith, Kyndle Nickens, and Charles Arellano.

The goal we were striving for is to cook sausages with a solar thermal cooker that demanded insufficient amount of materials as possible. With this solar cooker, the highest temperature achieved was 197 degrees Fahrenheit. This design would be useful to people with limited amount of resources, but still aim for cooking food with a hot surface. The materials needed to construct this solar thermal cooker is cardboard, string, spray adhesive, black paint, and aluminum foil. Make sure to have enough paint to over one half of the cardboard as well as having enough adhesive and foil to cover another whole half. The tools needed for this project are just a pair of scissors. As a group, we spent absolutely nothing on this project because these were common house-hold items or they were provided by the teacher. However, foil could cost around $1, cardboard can be found for free or bought for around $5, string comes in around $3, spray adhesive is around $2, tape is around $2, and black paint can be as little as $0.20. The total cost for this project can range for about $13.20. This project will take about half an hour to an hour. The cardboard box we used measured in to about 18 inches in length, 12 inches in width, and 12 inches in height. If you could not find spray adhesive, you can resort to using tape.

When completed, light will hit the panels that are in a vertical position and reflect onto the black surface. This black surface is the focal point, thus making this the area to cook the food in. The light becomes focused onto one focal point because the three panels are angled so that it will hit the surface. Not only will the surface gain light from the reflectors, but it will gain light directly from the sun as well. The sun will be directly striking the black surface which will increase the temperature. Since the surface of the focal point is black, this area will absorb the most heat. We do not want the surface to be white or brown because albedo will affect this. Some light will be reflected off of the surface if it is not black. Because black absorbs the most, this surface will ultimately be able to absorb the light energy and convert it into thermal energy, allowing for people to cook on it.

First, determine where you want to make the holes. These holes will be used to angel the panels correctly, so make sure the hole is big enough for the string to pass through. You need to put one hole on the left panel and one hole on the right panel that is equally the same distance from the center. On the other half, you need to put two holes that are symmetrical on the left side and the right side.

Now use the spray adhesive on the panels. Make sure to spray most of the surface on all three panels.

Once you have sprayed the three panels, now apply the Aluminum foil. Once applied to the surface, you can simply use your finger to rid of the bubbles that are found. You can simply press on the bubble and drag it out to an edge to rid of it.

Now, fold the cardboard in half so that the reflectors face down and the stand remains facing you. Take out your paint and paint the entire surface black. Make sure you are still able to determine where you have put your two holes on each side.

Once the paint dries, you are able to construct it now. Use the string to pass by one of the holes. Let’s start off with the top, most left hole on the stand. Once you put the string through that hole, make sure it passes through the left reflector hole and goes out through the right reflector hole. From here, put the string through the top, most right hole and now the string should meet the origin. Tie a tight knot so that the panels will be stable in a vertical position. If it is not tight enough, you can repeat the process, but this time use the second holes you made on the stand.

This project worked surprisingly well for the limited supplied used. We were able to get the surface hot enough to cook sausages. According to http://whatscookingamerica.net/Information/MeatTemperatureChart.htm, raw pork sausages need about 160 degrees Fahrenheit to cook, where pre-cooked sausages are need 140 degrees. This proves that our solar thermal cooker is able to cook sausages. Considering the amount of supplied used and the ability to achieve our goal, we are happy with the final product. If we were to do this again, I would certainly get a bigger piece of cardboard and a better reflector, instead of aluminum, to achieve better results.

Throughout this project, the only tool we needed was scissors. Not only are they great for cutting, but they are great for making holes with. All you just need to do is determine where the holes need to be placed and stab it with the scissors.

As a group, we would like to credit our teacher, Mr. Bording, for providing the materials that led to our success. We would also like to thank those who have helped provide support and ideas to help us become successful.