Cooking with Sunlight: Learn How to Cook Food With Solar Cookers

By Jennifer Andes
Published on May 1, 2003
1 / 2

A parabolic cooker, such as the one above, cooks nearly as quickly as a conventional oven.
A parabolic cooker, such as the one above, cooks nearly as quickly as a conventional oven.
2 / 2

This box cooker, made of wood, is used in Sri Lanka.
This box cooker, made of wood, is used in Sri Lanka.

When Louise Meyer and Dar Curtis invite guests over for dinner on a late summer afternoon, all the cooking is done outdoors. There are no charcoal grills or other fossil fuel-burning stoves to heat up and clog the air. Instead, appetizers, entrée, and dessert are all prepared with abundant, free, clean energy from the sun.

Find out how to build and use your own solar oven.

Meyer and Curtis use special ovens called solar cookers to prepare their food. With eight people expected for dinner, they have four solar cookers at work on Curtis’s patio. The food is ready one or two hours before dinner but stays warm in the cookers until the chefs transfer it to a buffet table where guests help themselves. The evening’s offerings: chicken baked in its own juices, ratatouille, Italian peppers–“slightly overdone,” Curtis allows–and to top everything off, banana cake. “Perfect!” Meyer proclaims, noting the dessert is moist on top yet browned around the edges.

Meyer and Curtis, both of the Washington, D.C., area, are partners along with Minneapolis sociologist Barbara Knudson in Solar Household Energy (SHE), a nonprofit organization that offers an alternative to wood-burning fuel in developing countries where trees are overharvested. Solar cookers, or ovens, also are useful in the United States as easy, practical, and economical ways to bake, braise, or stew food. Not only are they an earth-conscious cook’s best friend, but their outdoor location conserves energy. “In summer, you don’t have the air conditioner fighting with the oven to keep the house cool,” Meyer says.

Solar Cookers International (SCI), a nonprofit organization assisting communities to use the power of the sun to cook food and pasteurize water for the benefit of people and environments, traces solar cooking to the late 1700s, when European naturalist Horace de Saussure set out to show that a place is hotter when the sun’s rays pass through glass. He built a miniature greenhouse out of five glass boxes stacked inside each other on a black table. The outermost box stayed cooler, and the smallest box recorded the hottest temperature, 189.5 degrees Fahrenheit. “Fruits… exposed to this heat were cooked and became juicy,” he wrote. De Saussure experimented with other “hot boxes” and was able to achieve cooking temperatures that reached 230 degrees Fahrenheit regardless of the outside climate. He couldn’t explain how the hot boxes cooked the food, but physicists today say the phenomenon will work in any glass container exposed to the sun.

A solar cooker is a device that directs sunlight onto a dark-colored cooking pot, maximizing the amount of light energy that reaches the pot and minimizing the amount of heat loss. The essential elements of a solar cooker are sunlight, a black pot, reflectors, and a glass-covered box or a clear plastic bag. The black pot attracts the sun’s rays while the panel reflectors amplify them. Meanwhile, the glass or plastic prevents the heat from escaping, thus creating a “greenhouse” inside the solar cooker. As inventors and ecologists have experimented with hot boxes over the years, a variety of solar cookers have become available.

Comments (0) Join others in the discussion!
    Online Store Logo
    Need Help? Call 1-800-234-3368