Wednesday, August 12, 2009

Alternative Stoves & Solar Ovens

An Alternative Stove Worth It's Weight in Gold:
Last Christmas I opted to support a variety of charities in lieu of buying gifts for friends and families. In the process of searching for organizations, I came across the Darfur Stove Project - a program that brought together a group of UC Berkeley engineers and the women of Darfur, who have endured not only poverty and displacement, but the constant threat of rape every time they leave a camp to gather wood for cooking.
Check out the project story, donate if you can, and please pass it on to others.

The Berkeley Darfur Stove® is four times more efficient than traditional 3-stone fires and two times more efficient than clay stoves. The efficiency and design of the stove has many benefits including:

  • less time outside of the camps collecting fuel wood, reducing the risk of exposure to rape.
  • fully enclosed flames reducing the danger of the dense straw and stick shelters from burning down.
  • reduction of smoke production compared to other stoves, reducing smoke inhalation and lung disease.
  • saving time by cutting down fuel wood treks, allowing women to pursue income generating opportunities.

The website also has instructions for building your own Berkeley Darfur stove. What a great project this would be for a science class, a scouting adventure, or even a family project for your next camping trip.

Eco-friendly Solar Ovens

Solar Cookers or Sun Ovens harness the energy of the sun to bake, boil and steam a wide variety of foods. They're eco-friendly, relatively portable (depending on size), and uses a free fuel source. Even if you're not ready to cook full-time on a solar oven, it's a worthy investment for part-time use.

There are a variety of types of solar cookers: over 65 major designs and hundreds of variations of them. The basic principles of all solar cookers are:

  • Concentrating sunlight: Some device, usually a mirror or some type of reflective metal, is used to concentrate light and heat from the sun into a small cooking area, making the energy more concentrated and therefore more potent.
  • Converting light to heat: Any black on the inside of a solar cooker, as well as certain materials for pots, will improve the effectiveness of turning light into heat. A black pan will absorb almost all of the sun's light and turn it into heat, substantially improving the effectiveness of the cooker. Also, the better a pan conducts heat, the faster the oven will work.
  • Trapping heat: Isolating the air inside the cooker from the air outside the cooker makes an important difference. Using a clear solid, like a plastic bag or a glass cover, will allow light to enter, but once the light is absorbed and converted to heat, a plastic bag or glass cover will trap the heat inside. This makes it possible to reach similar temperatures on cold and windy days as on hot days.

Alone, each of these strategies for heating something with the sun is fairly ineffective, but most solar cookers use two or all three of these strategies in combination to get temperatures sufficient for cooking. -- Source:

Prices for solar ovens can vary from $40 to a small model for camping or fishing, to more than $350 for a large model designed for use as a primary stove. Solar Cookers International has a great "Solar Cooking Archive Wiki with lots of information and recent news. The wiki covers a variety of topics from the basics of solar cooking to water pasteurization and global usage.


Anonymous said...

A solar oven is definitely worth the investment (or time to make a homemade one). Not only do I use mine for cooking and baking, but like you said, it's great for purifying water and also sterilizing. Contrary to what some may think, you can use a solar oven year round.

Judy Sheldon-Walker said...

I have a friend who heats with wood and does not use a furnace. I am passing this on to her. I bet she would be fascinated, just as I am.
Thanks for sharing!