Cooking Up Kitchen Savings

Is it more energy efficient to use small kitchen appliances instead of an electric range? How do I determine how much it costs to use kitchen appliances?—Richard W.

Large electric cooking appliances in the kitchen can consume a lot of electricity. The electric range, oven, refrigerator, and dishwasher are the primary electricity consumers in most kitchens. New refrigerators have become much more energy efficient over the past decade, which is important because the refrigerator is the only one of these major appliances that you have little choice but to use continuously.

It is fairly simple to determine how much an electric appliance costs to use, but you’ll need a calculator. The nameplate on each appliance lists the wattage or amperage it consumes. If wattage is listed, multiply that number by the amount of time the appliance is used (in hours per use, per week, or per month), and then divide this by 1,000. This gives you the kilowatt-hours used. Multiply this number by the electric rate listed on your bill (in dollars per kilowatt-hour) and you’ll see how much the appliance costs to operate. If the nameplate lists amperage, multiply it by 120 to get watts and start your calculations.

Keep in mind that this calculation is an estimate, because many cooking appliances are thermostatically controlled—meaning on low setting, the heating elements are off most of the time. On high, they may be on all the time. Use your best judgment to estimate how long they are on for personal cooking settings.

Large quantities of food are usually most efficiently cooked on the range or in the oven. Most newer self-cleaning ovens have heavy wall insulation so they bake and roast fairly efficiently. A good rule of thumb is to use the smallest cooking appliance possible for the amount of food.

Using a high-quality, well-insulated slow cooker can also be an energy saver. For fast cooking, a pressure cooker dramatically reduces cooking time.

Small countertop convection ovens are efficient. Convection ovens have a small fan to circulate the heated air around food to cook it faster. Reducing cooking time reduces the total kilowatt-hours consumed and the heat generated in your kitchen. Some foods cook better without the convection air, but they will take longer. Of course, using a microwave oven saves electricity because the cooking times for small quantities are very short.

Using smaller countertop kitchen appliances can often result in less electricity use overall, but not always. Many factors, including the time of the year and your HVAC (heating, ventilation, air conditioning) system, determine this overall electricity use.

For example, if you air-condition your house and use the kitchen range during the summer, the heat from cooking makes the air conditioner run longer—the cost of cooking is effectively increased. The moisture given off from cooking also increases the air-conditioning load. If you do not air-condition, the cost of cooking is just the electricity the appliance uses. Whenever possible, use countertop cooking appliances outdoors, or use a solar cooker for rice and steaming vegetables.

Things are reversed during the winter. All of the electricity used for cooking ends up heating your house and reducing the heating load on your heat pump or furnace.

If you have a standard electric furnace or baseboard heating, the heat from cooking costs the same, making the added heat a cost-effective advantage. But if you use a heat pump for heating your house, you may be getting up to three Btu of heat for each one you pay for. The heat you gain from cooking costs you more than from your heat pump, so it is not as advantageous.