Overcooked myths: microwave ovens and home energy use
The roving finger of home energy blame finds another target in today’s New York Times. The microwave oven is portrayed as the biggest guzzler of home energy in a confusing table of bar charts and percentages.
It’s true that newer technologies with always-on or standby functions are increasing the demand for home electricity, but we must remember that these aren’t all simply adding to the demand — sometimes they’re replacing it. The microwave is a perfect example.
For small meals, the microwave is by far and away the most efficient (and by extension eco-friendliest, and cheapest) way of cooking. In fact, the same meal can consume less than 1/5th (pdf) the amount of electricty if cooked in a microwave rather than a conventional convection oven.
So why the confusion? Well, it’s true that the microwave does have a very high energy consumption rate of around 800 watts. But nobody has the microwave oven on all day. This is where the numbers can get misleading — power ratings (generally given in watts) must be multiplied by the time the device is actually in use to make for simple comparisons. A little bit of math reveals that the microwave’s quick heating ability results in a net gain in efficiency over conventional stoves (if not necessarily a gain in good flavor).