Around the world, solar ovens or “solar stoves” are increasingly being used to reduce people's dependence on firewood and other fuels. Even if you have electricity, a solar oven can be an effective, energy-saving addition to your cooking utensil. To build both a lightweight and a heavy-duty solar oven, follow these steps.
Step
Method 1 of 3: Solar Oven For light cooking
Step 1. Place a cardboard box inside a larger cardboard box
Make sure that there is at least an inch of space between the sides, and fill the gaps with strips of newspaper, which will act as an insulator.
Step 2. Line the inside of the smaller box with black cardboard, to absorb the heat
Next, cut the lid from the cardboard box into a clear square shape. Since you will be attaching the lid to the walls of your city, the width of each narrow end of each square must be equal to the width of the side where you will attach it; the width of each end should be a few inches wider than the width of the narrow end.
Step 3. Cover each sheet of cardboard with a light-reflecting material such as foil
Make sure it is firmly attached to the reflector, and smooth out any wrinkles or creases. Protect the material with rubber cement or one-sided tape from any light reflectors (glass).
Step 4. Glue each reflector to the top of one side of the box
You can glue, staple, or sew them as needed, leaving them to move around for now.
Step 5. Support each reflector at a 45-degree angle
The easiest, safest way to do this is to thread the reflectors together at the ends (eg by piercing the ends and tying them together with thread, then removing them to disassemble). You can also stick a rod into the ground under the reflectors, pile something under each reflector or use another method that will hold them securely in place. If it's a windy day, make sure your reflector won't be blown away by the wind.
If using rods, glue reflectors to the rods for added stability
Step 6. Position the oven in full sun, place the food in a smaller box, and wait for it to cook
It is best to cook food in a jug or in a small black saucepan. Experiment with cooking times and how and where you put the boxes. You may need to reposition your box several times during cooking to capture sunlight.
Method 2 of 3: Solar Solar For Heavy Cooking Jobs
Step 1. Cut a large metal drum in half vertically with a saw
An oil drum would be good for this project. Be sure to use a metal cutting knife; When you're done, half of the drum should look like a cradle. You only need half of the drum to make the oven.
Step 2. Clean the inside of half of the drum thoroughly with an oil-removing soap
Be sure to use a scrubbing brush and pay extra attention to edges and cracks.
Step 3. Measure and cut three pieces of sheet metal to contour the inner half of the drum
You will need one large rectangle for the curved inside and two semicircles for the ends.
- To make a large rectangular piece, one side should be equal to the length of what was previously the inner height of the drum; another equal to the length of the curved section of the interior, which you can measure using a flexible measuring tape (e.g. a sewing tape)..
- To make two halves of a semicircle: Measure the radius (half of the diameter) of the end half of the circle; tie a marker at the end of the rope then cut the rope according to the length of the fingers; holding the end of the string in the middle, use the marker to draw a perfect circle on the metal sheet; Cut the circle and cut it in half to make each cut a half circle.
Step 4. To attach the sheet metal to the inside of the drum with rivets, drill holes through both the sheet metal and the drum with 1/8-inch (3-mm) rivets, then attach the 1/8-inch (3-mm) rivets.
You can also punch holes through the sheet metal and drum and then attach them together with screws; although this will leave a screw tip on the back of your oven, the tape will eventually be covered with insulator.
Step 5. Paint the inside of the oven with a reflective paint that is safe for grilling meat
This will maximize the amount of heat in the oven.
Step 6. Make a continuous metal lip around three of the top four corners of the oven
This will hold the glass on top (where you'll slide it in and out through the fourth, open side) in place. The easiest way to do this is with four pieces of metal flashing:
- Measure the top edge of the oven and cut two halves of the flashing along this length. Then measure the long side of the oven, subtract the length of the flashing from this measurement, and cut the remaining four pieces of flashing along this length; this will allow you to apply flashing to the sides while making room for the flashing pieces at the end.
-
Place a piece of flashing over the edge of the end so that the bent metal “folds” from the outside vertical over the top horizontal end. Place the second flashing on top of the first flash so that the vertical side is the same height but the horizontal side leaves a gap wide enough to accommodate the thickness of the piece of glass. Place a strip of something (eg thick cardboard) between the two pieces of flashing to keep this open space, drill through both the flashing and drum, and secure it with rivets. Move and repeat on the other two sides.
Making a flashing sandwich (as opposed to just applying a single layer on the entire top) will keep the glass from rattling along the different ends of the cask that you cut by hand
Step 7. Turn the half drum upside down and apply an insulating spray to the outer wall
Make sure to apply it thinner than you think is necessary, as it will swell a little. See can for further instructions.
Step 8. Pin a base to the bottom of the oven
Simply drill and screw the drum into the base most convenient for your location (e.g. a piece of wood, Attach a base to the bottom of the oven. Simply drill and screw the drum to the base that is most convenient for your location (ex. a piece of wood, square aluminum frame with wheels, etc.), make sure that the base is wide enough to keep the oven from tipping over. Depending on your location, you may want to adjust the angle of the oven to get the most of the available sunlight (eg. north, you may want to set the angle towards the south whereas at the equator, you should face it directly up).
Step 9. Drill drainage holes in the bottom of the oven
Simply drill a small hole every few inches in a straight line along the bottom, making sure to penetrate the insulator; this will allow any moisture that drips down the underside to exit the oven.
Step 10. Slide the custom size tempered glass sheet onto the metal lip
Tempered glass is not only tougher than regular glass, but also with sharp edges, meaning you can use it that way. Since you will be sliding the glass in and out on a regular basis, choose a thicker piece (eg 3/16 inches / 5 mm) to make it stronger. You may have to order it specifically at a hardware store based on the size/dimensions of your solar oven.
Step 11. Insert the magnetic thermometer
A wood stove thermometer, for example, has a magnet behind it and can withstand high, continuous heat.
Step 12. Lay a thin aluminum grill along the bottom (optional)
Simply set up a rectangular grill or two for easy placing of food.
Step 13. Test your oven's heat capacity on a sunny day
While you wisely expect the maximum heat to be between 250 and 350 degrees F (90 and 175 degrees C), the size, materials, insulation of a particular part of your oven will determine how hot your particular oven model is. Use this temperature to slowly cook the meat for a few hours just as you would cook with a crock. Roast beef or chicken can take 5 hours, for example, while ribs can take 3 hours (plus 5 to 10 minutes of barbecue at the end). Measure the internal temperature of your meat with a food thermometer as you would when using an indoor oven.
Method 3 of 3: Solar Vegetable Steam Engine
Step 1. Get 2 cardboard boxes 1 inch (2.5 cm) apart, 5 cardboard panels, one much larger than the rest, Styrofoam, transparent wrapping, aluminum foil, black craft soap, black Tupperware (with lid), water, your favorite vegetables, glue, and 5 strong sticks
Step 2. Place the large box on the cardboard panel, glue it in place
Place the smaller box inside the larger box, glue in place. Eliminate all differences in height.
Step 3. Cover the empty space between the 2 squares with Styrofoam
Do not glue. Line the inside of the small square with 2 or 3 layers of black craft foam, glue them together. Cover the 4 cardboard panels with foil completely and glue the foil to the cardboard. Try to avoid wrinkling the tin foil.
Step 4. Glue the panels at a 45 degree angle to the box
Cut a bit of the stick to fit under the panel at an angle. Glue the sticks in place (to the panels and to the panels with a tin coating).
Step 5. Cut a rectangular hole just large enough to pass the Tupperware through one side of the stove
Glue the remaining sticks to Tupperware. Pass the Tupperware into the hole.
Step 6. Take the transparent wrapper and stretch it over the entire estuary of the solar cooker
Glue in place.
Step 7. Wait for a sunny day
Fill Tupperware with an inch of water. Put your vegetables inside. On a sunny day, leave the solar cooker on for an hour. Then go back and see if it's done. Repeat step 7, if needed.
Tips
- You can always make a light oven for a school project with waste (leftover materials)
- In a pinch, you can reheat pre-cooked food such as canned food with the ziplock bag trick: place the food in a small zip lock bag and place the bag in a large zip lock bag to trap heat.
- Positioning the rod supporting the heat reflector will be easier if you have someone to hold the heat reflector at the right angle when you position and glue the support rod.
- To make your light oven more efficient and to make it cook at a higher temperature, you need to trap heat. (without a cover, hot air will rise, bringing in a continuous stream of cooler air). Oven cooking bags are inexpensive and easy to use; Oven cooking bags are cheap and easy to use; it's easy, seal / cover the cooking pot in the bag. A panel of glass, especially a double pane of glass is an alternative solution. The glass should be slightly larger than the smaller box but not so big that it won't fit in the larger case.
- You should use the oven in an area exposed to sunlight. Energy for heating comes from sunlight.
Warning
- Ovens for light cooking do not offer sufficient protection against hungry animals. Make sure to place it in a safe area.
- Don't put your hands in a hot oven without protection, you can give it yourself.
- Be careful when baking food or utensils in the oven or when moving glass panes (if applicable). Since these are ovens, they can get very hot. Use a rag to hold pans, tongs, etc. Because you'll need it when you're working with a conventional oven or heat source.
- Lightweight solar ovens are effective almost anywhere you get direct sunlight, but you can't precisely control the temperature and time of cooking like you can with a conventional oven. Make sure the food is cooked to the recommended temperature using a meat thermometer.
- Never wash glass from a heavy-duty oven in cold water while it is still hot; temperature difference can crack the glass.
