Electric generators are used to supply power to homes, commercial and industrial establishments when there is a disruption of power. It is also used in places where there is no supply of electricity. Electric generators come in a wide variety of models, size, and prices. Choosing the right electric generator depends upon an individuals need. A homeowner first has to identify the appliances to be powered by the generator. The total wattage required to run these appliances has to be added up, including the starting wattage requirement of some of the appliances such as refrigerators. This makes up the total wattage power required from the generator. Lights and other smaller appliances require 120 volts of power, whereas appliances like electric stoves and driers require 240 volts. It should be checked whether the generators have the necessary voltage ratings.

There are few features that have to be considered before buying an electric generator. First, make sure to check to see if the engine has an overhead valve. An engine that comes with an overhead valve start easily, last longer and is less noisy. Second, check whether the engine has a cast iron sleeve in the cylinder to protect the engine from early wear and tear. In addition to this, electric generators come loaded with many convenient features such as electric start, power switch to alternate between 120 and 240 volts, low oil shut down that shuts the engines when the fuel in the tank reaches a certain level and an hour meter to show the duration of time the engine has been running. Electric generators are generally powered by gasoline, diesel, propane or natural gas. There are inexpensive but have a short life. Diesel generators are fuel-efficient, have a longer life but are relatively expensive. Propane and natural gas generators are best suited where fuel is ready available.

Certain precautions have to be taken while using generators. They should always be located outside the house to prevent exposure to harmful carbon monoxide. They should always be kept dry and should not be touched with wet hands to avoid getting electrocuted. Generators should not be refueled when in operation -- spilling of fuel on hot components may cause fire. It is always wise to invest in a good quality generator. Electric generators can be purchased at any appliances or hardware store. Industrial and commercial electric generators are available with their respective dealers. All brands and models of generators are listed on the web sites.