Solar Cooking

In a survival situation or apocalyptic scenario, it doesn't make any sense to waste energy gathering wood when its warm out. So how can you cook your food without this enormous energy waste? Make yourself a solar cooker.

Solar cookers are generally made with a reflective material that reflects sunlight onto a dark colored cooking vessel. They can range from simple to incredibly complex. In this I'll lay out three very simple types, two of which are really easy to build at home.

The first is by far the easiest and most common type. It basically consists of a cardboard box lined with tin foil or mylar. Take a square cardboard box, and cut one along a corner from top to bottom. Line the entire inside of the box with tin foil. I use spray adhesive, but any glue you have will work. Angle the flaps at the top and front slightly inward, but not so much as to block light. Trim out the spaces on the bottom so that the lower flaps can be angled slightly upward. Make another flat piece to put the opened box on top of. Put a black crockpot in the center and face it south. Depending on cloud cover and temperature you can fully cook a chicken in about five hours. By periodically turning the box towards the sun throughout the day you can increase its efficiency.

The second type is a little more involved but very doable. First you need a satellite dish. Any size will work, the bigger it is, the faster it works. Just keep in mind that even a small dish can start a fire. For the reflective material you can use tin foil but Mylar is much better on curved surfaces. Cut your reflective material (in this case Mylar) into thin triangles. Spray the dish with adhesive and smoothly apply the Mylar, rubbing out air bubbles as you go. Spray the backs of the strips just before you apply them to ensure a smoother surface. Find the distance that the reflected sunlight is focused and place the pot at the focal point. This cooker boiled a pot of water in about a half hour.

If you want to tackle a large project, a water parabola is really neat. The basic design is a clear plastic sheet suspended above the cooking area, filled with water creating a parabola. Start by finding the heaviest clear plastic available. Cut a round hole in a piece of plywood and attach the sheet to the top, giving it a bit of slack. Build a frame to suspend it about 6-10 feet in the air and fill it with water. The weight of the water pulls down on the plastic forming a parabolic lens. Now find the focal point and make a table that is the proper height. Obviously don't use anything flammable. If you build it big enough you can fry an egg in seconds.

Using these and similar methods you can cook your food, pasteurize water, and even start a fire.

Here's a cool video from Green power science