Hazy smoke wafting across the backyard or campsite, char-broiled burgers…these are the stuff of lazy summer-time cookouts. Except for one hitch: smoke and char-broiling not only pollute the air but aren’t good for your health either. For green-minded grillers (and those who just want a break from energy-intensive stove cooking), , solar power can be an eco-friendly alternative. Flame- and smoke-free solar ovens rely entirely on the sun's abundant — and free — energy to cook food and can be used virtually anywhere.
How to build and use a solar oven
Just as a closed car parked in direct sunlight becomes super-heated, solar ovens rely on the greenhouse effect to collect and trap the sun's energy and convert it to heat. But it can be tricky to time how long to cook food with a solar oven, so trial and error is often the name of the game. In general, solar cookers don't heat much beyond 300°F, so food tends to cook more slowly.
Sun ovens work best on cloudless days when the sun is highest in the sky (more than 45 degrees above the horizon) and ultraviolet (UV) rays are most able to penetrate the atmosphere. That means from April to October in the northern hemisphere, usually from 10 am to 2 pm In the early morning and late afternoon and during the winter months (November to March) the sun is usually too low to generate cooking-strength UV rays. As a general rule, use a solar oven when your shadow is shorter than your height or when the UV Index is seven or greater. To find out the current UV index in your area, visit the US Environmental Protection Agency's SunWise site.
If you're a DIYer, making your own solar oven is relatively simple. With just a few easy-to-find — including cardboard boxes to serve as the oven frame, aluminum foil to reflect sunlight into the oven, and a clear cover like plastic wrap to keep heat inside— you'll be able to concoct just about any culinary creation you'd bake in a conventional oven or grill. Get ideas and instructions on how to make your own solar cookers with one of these guides:
Find it! Solar ovens
For the non-handy, there are many affordable solar ovens available on the market, ranging from $30 to $300 and beyond. Here are just a few.
Before you buy
Because solar ovens rely on the strength of UV rays to cook food, it can be difficult on cloudy or other low-UV days to ensure that meat, poultry, and certain other foods reach adequate temperatures to kill potentially dangerous bacteria. To prevent foodborne illness, beef should reach an internal temperature of at least 145°F and poultry should reach 165°F. The US Department of Agriculture (USDA) recommends using a thermometer when cooking with a solar oven to make sure food is thoroughly done. Food-grade thermometers are inexpensive and make a good addition to your solar cooker purchase.
Buying a flameless solar oven helps you go green because…
- It doesn't require charcoal, gas, or electricity to operate, eliminating all greenhouse gas emissions.
- Because no flame is used and temperatures remain relatively low, solar ovens also minimize the formation of cancer-causing compounds that are created when meats are flame-grilled or broiled or baked at high temperatures.
Whether you're cooking indoors or out, meal-making takes an environmental toll. Gas and electric kitchen stoves represent about 8 percent of home energy use and contribute to greenhouse gas emissions. Barbecue buffs face a similar eco-dilemma: No conventional grilling method (whether charcoal, gas, or electric) is free from eco-impacts. One of the lowest-impact alternatives is a solar oven, which harnesses the sun's energy for smoke-free, no-pollution cooking.
Charcoal and wood burn "dirtiest," unleashing hydrocarbons as well as health-harming soot particles into the air. In addition, lump charcoal — made from pieces of charred wood — causes deforestation in many parts of the world and contributes greenhouse gases during production. Charcoal briquettes — molded from charred sawdust and wood scraps — are also greenhouse-gas contributors and often contain coal dust and other unhealthy additives. What's more, the 46,000 tons of lighter fluid used to fire up coals each year release about 14,500 tons of ground-level ozone-causing volatile organic compounds (VOCs).
Gas and electric aren't without their eco-drawbacks either. Natural gas is a fossil fuel, and electricity is often generated via coal-fired plants and other emissions-producing methods.
- volatile organic compounds (VOCs): Organic solvents that easily evaporate into the air. VOCs are emitted by thousands of products, including paints, cleaning supplies, pesticides, building materials and furnishings, and may cause immediate and long-term health problems. VOCs are also considered a possible carcinogen, and can create ground-level ozone, the main component of smog.
- CBS News - Cooking With The Sun: Solar Cookers Get Put To The Test By "America's Test Kitchen"
- [http://www.emagazine.com/view/?3664&src=QHA018 emagazine.com - EARTHTALK: Week of 03/25/2007
- Journey to Forever - Solar Box Cookers
- SFGate.com - Hot off the grid: Solar ovens utilize nature's rays for energy-efficient, everyday cooking - even in foggy San Francisco
- Sierra Magazine - Hearth & Home: P's and Q's of BBQ - A guide to guilt-free grilling
- US Department of Agriculture - Safe Food Handling: Do New Consumer Products Enhance or Endanger Food?
- US Environmental Protection Agency - Personal Emissions Calculator Assumptions and References