Cooking With Solar Power - Types of Solar Ovens

Cooking with solar power is a fun and novel way to prepare a meal. It won't replace your kitchen range but on hiking and camping trips, using the sun as an oven can provide a pleasant and enjoyable meal. With solar cooking, you can bake, steam and barbecue.

We are all familiar with how hot a car can get on a sunny day. As the sunlight hits the interior, it warms up the enclosed air. The trapped air can't escape and continues to get hotter and hotter and can reach temperatures up to 75 degrees Celsius. Simple solar ovens work in the same way. If we concentrate the sunlight, even hotter temperatures and faster cooking times can be achieved.

Black Box Oven

This is the simplest solar oven to construct. Take a small, black box with a removable lid and insulate the interior with a layer of newspaper or bubble wrap to trap the heat inside. Using a food container, place the food in the middle, close the lid and place in the sun. Just like a parked car with the windows rolled up, the interior will trap the heat and the air will get hotter and hotter. Limit the number of times you peer into the box to keep as much heat inside. Cooking time will depend on how large the box is relative to the size of the food item.

Enclosed Box Oven

Take a large, open-top box and line the interior with a layer of newspaper or bubble wrap and cover this insulating layer with tin foil (the shiny side out). To allow more sunlight to enter, cut the front of the box to half of the original height and slope the sides to the full height of the backside. Sunlight will enter the front and top of the box, reflect off of the shiny sides and concentrate heat in the middle. Use a piece of transparent or translucent plastic as a cover to trap the heat inside. This type of solar oven collects more heat and can even bake bread in just a few hours. Make sure you keep the box pointed directly at the sun.

Parabolic Reflector Oven

This type of oven uses a parabolic-shaped support to reflect the sunlight to a central point. Costly mirrors can be used, but aluminum foil works well. Depending on the size of the reflector, enough sunlight can be reflected to boil water and barbecue foods (it may take a few hours to rise the temperature). These are the most efficient solar ovens but require a proper mechanical support that will raise the cooking surface to the central reflection point. These types of ovens usually produce too much direct heat and are not good for baking.

Pros and Cons of Solar Cooking

Advantages:

• Uses free energy from the sun.
• When the sun is shining, solar ovens can provide a warm or hot meal at any location.

Disadvantages:

• Doesn't work at night or on overcast days. Sunlight is required.
• To work most efficiently, the oven needs to be continuously directed towards the sun.
• The food may attract insects and scavengers.
• Clouds and cold temperatures lengthen the cooking time.

Cooking with solar power is a novelty. It's not practical for everyday use, but can provide a hearty meal when travelling outdoors or in an emergency situation.