If you have dryer hookups in your laundry room for both electricity and gas, or if you are building a new house where either can be easily installed, you can choose between dryers in which a gas flame heats the air or an electrical element heats it. Gas dryers cost slightly more than electric ones but tend to be less expensive to run over time -- although how much less depends on energy prices where you live.
How Dryers Work
All dryers use electricity to rotate the drum that holds the items being dried and to run a fan that blows hot air into the drum. The difference between electric and gas dryers is that electric dryers also use electricity to provide the heat, while in gas dryers natural gas or propane provides it.
Here's the Hook
Electric dryers require a dedicated 240-V circuit. Your laundry room is likely to have this already. Gas dryers require a professionally installed gas hookup. Your laundry room might, or might not, have this already. If it does not, a gas dryer is unlikely to produce enough savings to justify the expense of installing one.
There is a small difference in price for equivalent models of gas and electric dryers, with gas being more expensive by about $50 to $150 as of 2014.
Assuming that you have a choice of hookups, the ultimate decision between gas and electric will likely come down to their relative running costs. This depends on the costs of gas and electricity, which vary widely from state to state, and also often from one time of year to another. Typically, however, a load of laundry will cost about twice as much to dry in an electric dryer as in a gas dryer. The California Energy Commission reports that an electric dryer completes a single laundry load for between 32 and 41 cents, as of 2014, while a gas dryer will cost you 15 to 33 cents per load. How much you save using natural gas over the life of the dryer would depend how much laundry you do.
Gas dryers heat up more quickly than electric ones, therefore making drying times shorter -- so they are generally kinder to fabrics. On the other hand, gas dryers naturally involve having gas in the house. Gas always brings with it the small but real possibility of explosion, and the process of burning gas results in small amounts of pollutants being released into the air in the house.
Consider a Line
All dryers, whatever their source of heat, are intrinsically inefficient. Consider hanging at least some of your washing out to dry on a line, at least in the warmer months. Sunlight and wind are, after all, entirely free.