How to Cook with the Sun

My test drive of a solar oven

My solar cooked stew (photo by Paul Greenberg)

What is the absolute lowest-carbon way to cook a piece of food? I’d been trying to reach a definitive conclusion about this question for a book I was writing about lifestyle and climate change. Online there was a heady debate about gas versus electric ranges. On the one hand electric conducts heat from a stove top much more effectively into the food you’re trying to cook, something like twice as efficiently as natural gas. On the other hand, if you’re a baker, filling up an oven with heat that must surround your food on all sides can be done more effectively with gas. On still another hand, gas is leaky and methane-based and on its way down the pipeline to your stove it often escapes and creates a greenhouse problem since methane is 30 to 50 times more potent at trapping heat in the atmosphere than CO2. On a fourth hand, until we switch the national energy grid over to renewables, a lot of the energy we use when we choose electric is going to come from coal, which is way worse than everything. Frankly all of these hands had tied me up in a knot.

And that’s when I found out about solar ovens.

Solar ovens are basically boxes surrounded by large panels of reflective materials that direct the sun’s radiation inward to food placed in said box. No plugs, no gas, no nothing, except the sun. They were first…