Super Solar Oven

Posted by: admin on Aug 17, 2012 | No Comments

You can use the sun’s energy to heat up a tasty treat with this simple solar oven! (Get an adult to help you with the cutting and to advise on the cooking.)

You Will Need

Cardboard pizza box (the kind delivered pizza comes in)

Stanley knife or scissors, Aluminium foil, Clear tape, Large heavy-duty, or freezer zip lock bag

Black sugar paper, Newspapers, Ruler, or wooden spoon
Instructions
Use the knife or sharp scissors to cut a flap in the lid of the pizza box. Cut along three sides, leaving about an inch between the sides of the flap and the edges of the lid. Fold this flap out so that it stands up when the box lid is closed.

Cover the inner side of the flap with aluminium foil so that it will reflect rays from the sun. To do this, tightly wrap foil around the flap, then tape it to the back, or outer side of the flap.

Use clear plastic from your bag to create an airtight window for sunlight to enter into the box. Do this by opening the box, cut out a square of plastic from your bag big enough to cover the opening, and tape over the opening.

Leave about an inch of plastic overlap around the sides and tape each side down securely, sealing out Line the bottom of the box with black construction paper – black absorbs heat. The black surface is where your food will be set to cook.

 

To insulate your oven so it holds in more heat, roll up sheets of newspaper and place them on the bottom of the box. Tape them down so that they form a border around the cooking area. The newspaper rolls should make it so that the lid can still close, but there is a seal inside of the box, so air cannot escape.

The best hours to set up your solar oven are when the sun is high overhead – from 11 am to 3 pm. Take it outside to a sunny spot and adjust the flap until the most sunlight possible is reflecting off the aluminium foil and onto the plastic-covered window. Use a ruler to prop the flap at the right angle. You may want to angle the entire box by using a rolled up towel.

 

You can make toast by buttering a slice of bread, or sprinkling cheese on it, then letting the sun do the rest. It would also work great to heat up leftovers. So the paper at the bottom doesn’t get dirty, put what you would like to cook on a clear plastic or glass plate. A pie plate would work well.

To take food out of the oven, open up the lid of the pizza box, and using oven mitts or potholders, lift the glass dish out of the oven.
What’s Happening?
The heat from the sun is trapped inside your pizza box solar oven, and it starts getting very hot. Ovens like this one are called collector boxes, because they collect the sunlight inside. How does it happen? Rays of light are coming to the earth at an angle. The foil reflects the ray, and bounces it directly into the opening of the box. Once it has gone through the plastic wrap, it heats up the air that is trapped inside. The black paper absorbs the heat at the bottom of the oven, and the newspaper make sure that the heat stays where it is, instead of escaping out the sides of the oven. Your solar oven will reach about 200° F on a sunny day, and will take longer to heat things than a conventional oven.

Top Tips You can also pre-heat your oven by setting it in direct sun for up to an hour. Even on partly cloudy days there may be enough heat and light from the sun to slow cook a special dish. Stir liquids (if you’re cooking something like fondue, rice, or soup) every 10 minutes and rotate solid food every 10-15 minutes as well, so it cooks evenly.

Thanks to, and adapted from hometrainingtools.com

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