It is very easy to turn on an electrical device and have it work; but have you ever wondered what powers a television set, a Playstation 2 game console, a telephone, the lights in your house, the ceiling fan above your bed or the radio in your room? Electricity is the reason that all of these devices work and meet your daily demands each and everyday. The force of electricity is relied by all of mankind as a building block for modern society.
Electricity is a form of energy and is the flow of electrical power. In order to power electrical devices, an uninterrupted flow of electricity is key. Atoms make up every form of matter in the universe. All atoms have a nucleus, or center/core, which contains positively (+) charged particles known as protons, and uncharged particles, neutrons. Surrounding the nucleus are negatively (-) charged particles called electrons. Electrons and protons, if added together will usually equal zero, a neutral charge, this is because in a balanced atom the number of protons will equal the number of electrons. When an outside force upsets the balancing force between protons and electrons, an atom may gain or lose an electrical charge. An electrical current is caused when a charge is lost from an atom.
Many pioneers have experimented with electricity to better comprehend how it works. Following Benjamin Franklin's notorious kite experiment, the principles of electricity became more understood. Thomas Edison invented the electric light bulb, which was safer inside buildings. Prior to Nikola Tesla's inventions, direct current was the only use for outdoor lighting. Tesla pioneered the generation, transmission and began to use alternating current electricity. Alternating current can be transmitted over greater distances than direct current.
A transformer was invented by George Westinghouse to send electricity over long distances in order to supply customers with electricity that were located far from the generating plant. Transformers change electricity from low voltage to high voltage allowing for the electricity to travel more efficiently.
Electricity is measured in units known as watts (W), named for their founder, James Watt. James Watt invented the steam engine also. One watt of power is extremely small; therefore, they are usually designated as kilowatts (kW), which is equal to 1000 watts. The amount of electricity used over a specified period of time is known as a kilowatt-hour (kWh). Prices of kilowatt-hours vary throughout the country from a low price of 4.26 cents per kWh in Kentucky, to a high price of 13.39 cents per kWh in Hawaii. The major difference in price is due to the location of readily available electricity. Kentucky is a major producer of coal. The overall national average price is 7.21 cents per kWh.
The basic devices used in the generation of electricity are generators; these generators convert mechanical energy into electrical energy. Generators are a method based on the relationship between magnetism and electricity. A large magnet is positioned so that when it rotates, a small electric current is induced in each section of wire. All of the currents in each wire when summed up equal a current of considerable size. This large current is used for electric power.
Several different types of electrical generating units are operated with a wide range of fuel sources. Electric utility power stations use turbines, engines, or water wheels to convert mechanical or chemical energy to electricity by driving an electric generator. The most common methods of generating electricity is by the use of steam turbines, internal-combustion engines, gas combustion turbines, water turbines and wind turbines. Most of the electricity in the United States is produced using steam turbines.
In a turbine, the kinetic energy of a moving fluid, either liquid or gas, is converted into mechanical energy. A wide range of fuel sources are used as a form of force to turn a series of blades mounted on a shaft, which rotates the shaft connected to the generator, thus creating electricity.
Electricity is a secondary source of energy that comes from the conversion of other primary sources. These primary sources include fossil fuels, uranium and renewable sources.
Coal, petroleum and natural gas encompass the use of fossil fuels in electricity generation. These fossil fuels are burned in gas turbine generators where the hot gases produced from combustion are used to turn the turbine blades, which in turn spins the generator to produce electricity. Petroleum is also burned in generating units with internal-combustion engines; these internal-combustion engines are where the combustion occurs inside cylinders of the engine that are connected to the shaft of the generator. The engine drives the generator to produce energy off of the mechanical energy provided from the generator. In 2001, roughly 51% of the country's kilowatt-hours of electricity used coal as its source of energy. Less then 17% of the nation's electricity was fueled by natural gas, while only 3% of all the electricity was generated using petroleum.
Another means of electricity generation comes from the method of nuclear power. Nuclear power takes place from a process known as nuclear fission, in which atoms of uranium fuel are hit by neutrons. When this collision of uranium and neutrons occurs fission takes place, releasing heat and more neutrons. This process occurs continuously, forming a chain reaction releasing heat. The heat is used to transform water into steam, which spins the turbine that generates the electricity. Nuclear generating units accounted for the second largest portion of electricity generation in the United States at a share of nearly 21%.
Hydroelectric power units use flowing water to spin a turbine that is connected to a generator. There are two types of hydroelectric systems that produce electricity, the falling water system and the run-of-the-river system. The falling water system uses dams. Flowing water accumulates in reservoirs that release water through a pipe and applies pressure against the turbine blades to drive the generator. The run-of-the-river system uses the forces created by the rivers current to apply pressure to the turbine blades to produce electricity. Approximately 7% of all electricity production in the United States was produced by the use of hydropower.
The use of non-water renewable sources of electricity generation currently contributes about 2% of the total power production in this country. Geothermal power comes from heat energy trapped beneath the surface of the earth. In geothermal powered units of electricity generation, the underground water is heated to extreme temperatures as it reaches the surface thus, being released as steam. Solar power comes from the energy emitted from the sun. The uses of photovoltaic cells, which generate electric power directly from the light of the sun, have proven to be more costly then fossil fuels. Radiant energy from the sun is used to produce steam to drive turbines in solar-thermal electric generators. Wind power is the conversion of wind-generated energy into electricity with the use of windmills. The burning of biomass materials provides another means of generating electricity. Biomass includes wood, garbage and agricultural waste. These sources are burned in the same manner as fossil fuels, thus creating electricity by producing stream to rotate the turbines.
Electricity is an important aspect of modern society. Think about how often you use and rely on your electrical appliances, now think about the process that goes into producing the electricity that enables you to have the modern comforts that you are so dependent upon. With the ever-increasing prices of electricity and the depletion of the ozone layer by greenhouse gases, a discovery in cleaner burning methods of generating electricity is vital. As many of the resources in use today are being used to supply the world with electricity, technological advances are constantly being realized with the renewable resources and more ecologically safe methods of electricity generation.