Science, not Home Economics
The problem with too many environmentally conscious types is that they are scientifically un-conscious—too willing to believe any green claim made by advertisers. So I was very glad to find some fellow skeptics at the Eskom eta Awards: the girls of the Clarendon High School Coelacanth Enviro Club in East London.
Like me, these high school students were intrigued by a new type of stove, induction cookers, which promise huge energy savings. These devices use magnetic fields to heat a pan or pot, which must be made of iron or steel. The companies selling them typically claim that induction cooking uses half the electricity because it is faster than a conventional stove. The Coelacanth Club put these claims to the test.
Cooking a range of foods on both an ordinary spiral hotplate and an induction cooker, the girls found that the induction cooker reduced electricity consumption by 19 percent on average. The savings were high when intense heat was required: 33 percent for boiling water and 30 percent for deep-frying potato chips. For simmering, the savings were less impressive. In fact, the induction cooker was no more efficient than the spiral stoveplate when making fudge (These girls were definitely not on a diet.)
I’ve crunched their numbers to get a sense of the savings in rands. If every day for a year you cooked their “meal” of boiled water, fudge, mashed potato, potato chips and creamy chicken, you would save R130 a year at a typical rate of R1.20 per kilowatt hour—and you would gain a lot of weight. Since induction cookers cost anywhere from R600 for the Prima brand at Makro to R1200 for the Snappy Chef brand used in the Clarendon test, it will take several years before the cooker has paid for itself.
There are other advantages to induction cooking, however. The pan reaches high heat levels much more quickly, saving time. The pan heats but the stove does not, so it is safer. Most models shut off automatically when the pan is removed, which will save ditsy cooks even more on their electricity bill. Finally, your cooking carbon footprint will fall, as long as you are not cooking fudge.
But the Clarendon girls found that for the ultimate in low-carbon stove-top cooking, gas is by far the best option. Preparing the same range of foods on a gas stove cut carbon dioxide emissions by an average of two-thirds. Greening your kitchen emissions by using to gas can be either cheap or expensive, depending upon where you live. The lucky Jo’burgers with access to Egoli Gas can save money compared to cooking on electicity. Unfortunately, for the rest of us, using bottled gas at the current price of R1225 for a 48 kg cylinder means paying 88% more compared to powering an ordinary electric stove.
More environmentally friendly meals can come without any pricetag, however, according to the Coelacanth Club. Their research shows that simple improvements in cooking techniques, such as using lids, simmering on low heat once food has come to a boil, and using only as much water as needed, can save about 40 percent of the energy required to cook more inefficiently.
The Clarendon Coelecanth Envio Club won the Young Designers category at the eta awards. And we have all won in the kitchen by learning from their efforts.