How Generators Work

By Toni C - Feb 7, 2012

A generator is essentially a device that converts one form of energy to another. In the world of electricity, an electric generator usually relies on the input of mechanical energy to produce electrical energy.

Much like a water pump does with water, an electric generator forces an electrical charge to flow through it, releasing this energy through the output end of the generator. Just like a water pump does not actually create water, an electric generator does not actually create energy but simply converts mechanical energy into usable electricity.

Most modern day generators use the principle of electromagnetic induction to make electricity. This principle states that electric charges can be forced to flow steadily by placing an electrical conductor in a magnetic field and causing it to move. The movement of this conductor gives each of its ends a different voltage, and this in turn forces the electric charges to move in a single direction, creating a flow of electric current.

The mechanical energy used to produce electrical energy may be obtained from a number of different sources including wind, steam, or flowing water. The vast majority of personal electric generators rely on internal combustion engines to create energy through burning fuel. While there are many different kinds of fuel available, the main ones that are used in today’s electric generators include gasoline, diesel, and propane.

Gasoline is the most widely available fuel, but it is also very expensive and highly flammable. Diesel is considerably less flammable, less expensive, and has a longer shelf life. It may, however, cause a greater amount of noise and produce more emissions. Propane has a long shelf life and is easier to store for long periods of time. It is a relatively clean fuel to burn and produces less engine noise than diesel. Propane tends to be more expensive than other fuels. Engines that run on propane are often quite complex and have a higher possibility of failure. Other less-popular fuel options include natural gas, bio-diesel, and emulsified diesel.

Electric generators generally come with a fuel tank in which to store the fuel and an engine in which to burn it. Other essential components of most electric generators include the alternator, which produces the magnetic field; the voltage regulator, which controls the electrical output in terms of voltage; and the exhaust and cooling systems, which employ efficient cooling liquids to ensure that the generator does not overheat.

As far as output is concerned, there are two main types of electric generators, standard generators and inverter generators. While the engine of a standard generator runs at full throttle regardless of how much of its electricity is being used, the engine of an inverter generator can run at variable speeds. An inverter generator can run slower and therefore use lower quantities of fuel when less of a load is placed upon it, or it can throttle up and run at a high speed when more electricity is needed. Although the cost is typically higher than standard generators, inverter generators are more energy-efficient and friendlier to the environment. Inverter generators are most suitable for sensitive electronics and situations where there will be a great degree of fluctuation in the amount of electricity needed.

When considering which type of generator to use at home, in your business, or the great outdoors, it’s important to always keep in mind your fuel storage needs, noise level requirements, power fluctuation needs, and portability requirements.