IT took us four hours to cook one cup of rice on a partly sunny summer day in Boston, but there will be no gas or electricity bill to pay, and we didn't use a nonrenewable energy resource. Plus, cooking in a solar stove was fun: following the moving shadow of the sun; re-aiming the panels to get maximum sunlight on the food; frowning when clouds moved in, covered the sun, and quadrupled the usual cooking time for rice.
But in some climates, where clear days are more abundant than firewood, cooking with the sun is a sound alternative.
Fifty years ago, inventor Merton (Bud) Clevett set out to make such a solar cooker, spurred by an article in this newspaper that described an African woman's daily, 10-mile trek to secure firewood. Mr. Clevett wanted to design a cooker that could be shipped and copied easily.
Since then Clevett has designed more than 100 solar stoves; he and his wife manufacture six models at their Clevlab headquarters in Littleton, Colo. The stoves range in size - from one-person meals to enough for 10 - and in price - from $20 to $475. He once custom-made a unit that used photovoltaic cells to operate a rotisserie.
His most popular model, the one we tried last week, is the Sunspot, a 10-inch-square cardboard box surrounded by foil-laminated panels that direct sunlight downward, through a clear plastic window over the food. Temperatures can reach 375 degrees F. on a sunny day, and the oven can cook a range of foods: meat, potatoes, bread. Sunspot weighs only 20 ounces and folds to 4-by-10-by-10 inches - convenient for backpackers to carry on camping trips.