For the 12 years I’ve known her my friend Edie Farwell has been an enthusiastic proponent of a type of oven powered by sunlight. She’s on the board of Solar Cookers International, an organization that’s been promoting the use of homemade solar ovens as a way to save fuel, reduce emissions of carbon dioxide, and cook great food since the 1970s. These cookers are particularly important in third-world countries where firewood is scarce and heat from the sun abundant. I’d seen pictures of the gizmo, and the idea that a couple of cardboard boxes, some aluminum foil, and glue could effectively cook good-tasting food seemed unlikely. But three summers ago I agreed to build one and check it out.

Feeling as though I’d returned to the basement of the Griffin Christian Church to make crafts for vacation Bible school, I surrounded myself with two cardboard boxes, a roll of heavy-duty aluminum foil, some toilet-paper tubes, newspaper, a sheet of glass, and a big bottle of Elmer’s glue. Following a Solar Cookers International design, I suspended the smaller box inside the larger one, supporting it with cut-up cardboard toilet-paper tubes, and stuffed newspaper between the two boxes for insulation. I lined the inside of the inner box, which would form the interior of the oven, with aluminum foil and topped it with glass. I also constructed a lid for the outside box that fit tightly over the whole thing and had a foil-surfaced flap to direct the maximum amount of sunlight into the inner box.

The next morning I cut up potatoes and peeled garlic cloves, placed them in a pot I’d painted with oven black, drizzled olive oil over them, and sprinkled them with salt, pepper, and fresh sage. Then I carried my happy-hands-at-home project up to the tar roof of my two-flat.

It was an 83-degree day, and the sun beat down on my shoulders as I positioned the box and adjusted the reflector to push stray rays into the oven. I knew a black pot sitting inside a glass-topped, insulated box couldn’t be chilly, but I still doubted that this contraption would actually cook anything. My car grew hot sitting in the sun too, but I didn’t imagine I could bake a tuber on the dash. For objective evidence I lifted the glass and stuck a meat thermometer next to the pot.

I stared at it for a bit and tried to think if there was anything else I needed to do. My only remaining task was to leave the box the heck alone, but this didn’t feel like enough. I wanted to stir, smell, adjust, taste. I wanted to be involved in the process. I climbed downstairs, but every ten minutes I was back up on the roof to see what was happening. Other than the needle escalating on the thermometer, there was nothing to see but a cardboard box that once held Florida oranges. In less than 30 minutes the temperature had shot up above the highest mark on the meat thermometer, 190 degrees. From the position of the needle, I guessed it was at least 200 degrees inside the box.

The best way to ensure good solar cooking is not to open up the cover, because that quickly dissipates the heat. Still I wanted to feel how hot it was and see how the potatoes were doing. After an hour–the temperature was probably about 250 degrees by then–I opened the cover. I hadn’t thought to bring hot pads, so when I touched the pot lid I burned my finger. Embarrassed, I left the potatoes in peace.

Solar ovens can cook just about anything other ovens can–beans, rice, vegetables, bread, meat, fish, chicken, brownies, cookies. Solar cookers can also be used to pasteurize water, important in developing nations, where many diseases are spread by unclean drinking water. Since my solar cooker debuted–producing steaming, succulent roasted potatoes–I’ve used it a lot. It’s been particularly welcome this summer, when the idea of heating up the kitchen on a 95-degree day is less than appealing. All I have to do is carry the box to the roof, stick a pot in it, and leave for work. By noon I can have lentils, rice, or corn on the cob for lunch. Even if I leave the food in the oven all day it doesn’t overcook, and when I come home it’s sitting there warm and ready to be eaten for dinner.

I can attest that solar ovens cost little, work great, and are convenient. So why am I the only person in Chicago who seems to know about them? As addicted as midwesterners are to kitchen fads–fondue pots, juicers, woks, bread machines–why hasn’t there been a solar-oven fad?

“It’s not fast, and people like fast,” Edie suggested when I posed the question to her.

Yeah, but people liked the Crock-Pot for a while–and it required you to prepare the meal in the morning and let it simmer all day, which is much the way I use the solar oven.

“Well, it has to be a nice day,” Edie said. “You have to interact with your environment–you can’t just flip a switch and have it work.” This is true, although two or three hours of sunlight are often enough to cook whatever’s in the box. Intermittent gray skies don’t ruin a meal, though rain is a problem. Not that I’m panicked about the food. I just don’t want the cardboard to get soaked and fall apart. But solar ovens can easily be made out of water-resistant material–Edie’s is made from wood. And there are woven-basket cookers in Nepal, dung-brick cookers in India, adobe ones in the southwest, laminated-juice-packet ones in Spain. There’s no magic in cardboard.

Edie’s third response was “It’s very, very low-tech. People look at it and say, cook in something cardboard? You can’t be serious.” Since this wasn’t far from my original feeling about the enterprise, this theory strikes me as closer to the heart of the issue, at least in America.

I’m accustomed to having the equipment around me–the gas stove, the refrigerator, the washing machine–powered by mechanisms I don’t entirely understand. I can’t construct these machines myself, I can’t even repair them. It’s perverse, but if the solar oven had been more like that–if it had used photovoltaic cells perhaps–I might have started using one sooner. And I know I would have been more confident of its effectiveness if Williams-Sonoma had been mass-marketing a model out of sleek, modern materials at an appropriate price.

The passivity of solar cooking continues to be maddening for me. The only action I have taken in cooking my food in the solar oven is building the thing (which was accomplished in a single afternoon) and setting food inside it. There’s nothing I can do to increase the speed at which my dinner cooks. I can’t throw on more firewood or charcoal or turn up the flame. A cloud bank may roll overhead, but there’s nothing I can do to mitigate its cooling effect. The most I can do is occasionally use my forefinger to push the box a couple inches so the angle of the sun is more direct.

The staff and board of Solar Cookers International has a conference display that shows two women cooking: one stands over a stove, slaving away, stirring, steam billowing into her face, while the other sits by a swimming pool reading a magazine with her solar box cooker in the background.

We think we want to be the second woman, and it’s much more logical to want to be her–but something compels me to want to be the first. Still, I’ve nearly managed to adjust to the leisurely pace of solar cooking, and every time it works I feel the thrill of magic. So, doing my part to free women and men everywhere from hot kitchens and dependence on Peoples Gas, here’s how to get instructions to build your own oven: You can pull the design directly off Solar Cookers International’s Web site at

seer/sbcn/index.htm. (The Web page also offers photographs of different styles of cookers to inspire you.) Or write the crew at 1724 11th St., Sacramento, California 95814. Or call 916-444-6616.