Microwave Ovens

Cooking with a microwave oven instead of the stove can save you money. Fast and efficient microwaves use from 30 percent to as much as 80 percent less energy than conventional ovens. They also have the added benefit of not heating up your kitchen, so they can save you money on air conditioning in the hot times of the year.

Microwaves ovens use very high-frequency radio waves to penetrate the surface of food to heat water molecules inside. These energetic waves can greatly reduce cooking times and energy consumption for preparing certain foods, especially in small amounts. That's why microwave ovens are especially efficient for smaller portions or for defrosting things. When it comes to large items, however, using your oven or stovetop is usually more cost effective.

For the most economy, consider several ways of cooking, including toaster ovens and crockpots - those insulated ceramic pots with built-in electric heating elements. This table from the Consumer Guide to Home Energy Savings compares the cost of cooking a casserole in several ways. It assumes the cost of gas is $.60 a therm, and electricity is $.08 a kWh.

ApplianceTemperatureTimeEnergyCost
Electric Oven3501 hour2.0 kWh$.16
Electric Convection Oven32545 minutes1.39 kWh$.11
Gas Oven3501 hour.112 therm$.07
Electric Frying Pan4201 hour.9 KWh$.07
Toaster Oven42550 minutes.95 kWh$.08
Electric Crockpot2007 hours.7 kWh$.06
Microwave Oven"High"15 minutes.36 kWh$.03

Smart Buying

Consider these tips when shopping for a new microwave oven:

  • The energy efficiency of different brands of basic microwave ovens does not vary greatly. As a result, microwaves are not appliances that display ENERGYGUIDE labels or receive ENERGY STAR ratings. Generally speaking however, a small or compact microwave - rated at 600 to 800 watts -- is probably more energy-efficient than a midsize or large one, typically rated at 850 to 1,650 watts. Don't buy a bigger microwave than your family needs.
  • Newer models of microwave ovens include features that improve energy efficiency and cooking performance. These include temperature probes, sensing controls that tell by moisture content when food is properly cooked, and variable power settings.

Smart Use

Remember these tips to use your microwave efficiently:

  • Microwaves are most efficient for small portions or defrosting. For large meals, stovetop cooking is usually more efficient.
  • Microwaves aren't appropriate for all cooking; they can cook food unevenly and they can't brown food. Microwaves are especially good for small portions and leftovers.