There are many choices today with respect to cooking appliances. Ranges that combine an oven and cooktop remain very common, but separate oven (particularly built-in style) and cooktop units have become increasingly popular as kitchens have grown. These stand-alone units allow for multiple ovens, additional burners, or a space for grille or griddle inserts.

Microwave ovens have gained in popularity since they were first introduced in the early 70s, due in part to a decrease in price but also to the gradual acceptance of this form of cooking. Today, most packaged foods give directions for microwave as well as conventional cooking. Electricity is still the most common energy source for cooking, accounting for 61% of all ranges in the US. Many cooks prefer gas cooktops because of their instant temperature control and even heat distribution, but they are often 50% more expensive than their electric counterparts.

Cooktops
Electric resistance coil cooktops have long been the standard in the U.S. Gaining in popularity are solid disk, radiant, halogen, and induction elements. These smoothtop cooking surfaces have been popular in Europe for years, but it is only recently that sales have reached 20% share of the electric market.

DOE has estimated that coil elements are roughly 6% more energy efficient than smoothtop elements. However, a 1994 study by Arthur D. Little found that there is no clearly defined correlation between element type and efficiency. Neither DOE nor Arthur D. Little reported specific data on solid disks, but several tests have found the efficiency of solid disks to be significantly less than the other styles, perhaps by as much as 20%.

The two common types of gas burners in the U.S. are conventional burners and sealed burners. Sealed burners are only available with electronic ignition, although even with conventional burners electronic ignition dominates the market. Sealed burners are fused to the cooking surface, the primary benefit to this being the absence of hard-to-clean spaces. As an additional benefit, DOE estimates that sealed burners are almost 5% more efficient than conventional gas burners.

Ovens
Ovens are the least efficient cooking. With electric ovens, DOE estimates that only about 12 or 13% of the heat produced goes to actually cooking food (with cooktops this figure is about 70% to 80%). The remainder is absorbed by the oven walls and then conducted to the air in the kitchen. With gas ovens it is estimated that wasted energy is a staggering 94%. Gas ovens lose additional heat through the flue and also as a result of incomplete combustion.

Based on DOE estimates, the typical cost of operating a gas oven is $22 annually with a pilot light or $13 with electronic ignition. For electric ovens, the cost is about $29 for a self-cleaning oven and $27 without the self-cleaning feature. This is based on national average fuel prices.

Most ovens sold today are self-cleaning, even though this style adds about $70 to the cost of a typical oven. Interestingly, while the self-cleaning process is a heavy energy consumer that requires the oven to reach temperatures of 850 degrees, these high temperatures require better insulation that reduces the energy consumption during cooking. The result is that self-cleaning ovens use almost the same amount of energy as manual cleaning styles.

Convection ovens circulate air throughout the cooking chamber in order to increase heat transfer to foods and reduce cooking times. Convection cooking is becoming more popular, but acceptance has been slowed by cost and the forced change in cooking habits (cooking times need to be reduced to account for faster heat transfer). Reported efficiency gains of convection cooking varies tremendously. DOE estimated that convection cooking would increase efficiency by 23%. However, Arthur D. Little reported the results of manufacturers tests which showed an improved performance just over 2%. Such variances can be accounted for by the generally accepted theory that convection efficiency is largely dependent on the kind of food being cooked.

Electric versus Gas
Gas cooktops, as noted earlier, often come with a price tag 50% higher than electric models. Of course, there are other things to consider when choosing between the two fuels, among them the operating cost. While a gas cooktop generally requires a greater initial investment, DOE estimates that a new gas cooktop costs $11 per year to operate. Compare this to $24 per year for electric, and you see that the purchase price is only part of the picture.

What about performance characteristics? Each fuel has its benefits and limitations. Gas cooktops have instant temperature response, but many gas elements have difficulty maintaining a low flame. Electric can provide low level heat for very delicate cooking, and it is also better suited for high capacity such as boiling large pots of water. However, electric coil elements provide rather uneven temperature distribution, and warped-bottom pans are not well suited to electric cooking.

What is involved in switching from electric to gas cooking?
The first thing you have to determine is the feasibility of getting gas service to your house if you don't have it already. The next step is to get the gas from the service to your kitchen. Feasibility of gas in your house: If you do not yet have gas service in your house you can check with a local gas distribution company for availability and any associated costs. Some companies will provide a free installation if you are within a certain distance of a main gas line. If you are beyond this range you might have to pay for the installation or you might not be able to get gas service at all. Gas supply to the kitchen: Running a gas line from the service to the kitchen can be a complicated and costly proposition. First check to see that you don't have gas already. Even if you have an electric range, there might be a gas line that was shut off during renovation. New homes are sometimes built with both electric and gas supplies in the kitchen to accommodate future remodeling. If you don't have a gas line to your kitchen, you can get a free estimate for this work from most plumbers. The price will typically range from $200 to $500 depending on the location and configuration of your kitchen.