BizAims

The electric power industry plays a critical role in our society on many levels. It advances the nation’s economic growth and productivity; promotes business development and expansion. It is a robust industry that contributes to the progress and prosperity of our nation.It provides the nation with the most prevalent energy form known — electricity. It powers our homes, offices, and industries; provides communications, entertainment, and medical services; powers computers, technology, and the Internet; and runs various forms of transportation. Not only is electricity the cleanest, most flexible, and most controllable form of energy, its versatility is unparalleled. Clearly electricity is a crucial commodity we all take for granted. We scarcely think about it, unless we don’t have it. Fortunately, almost without exception, electricity is there for us when we flip the switch.

 Delivering electricity to consumers is a complex task. Behind it lies a series of highly technical functions such as the generation of power, its transmission, and its final distribution to the consumer. Because of the physical nature of electricity, the entities performing these functions are not isolated. To a degree, all power suppliers and delivery systems are interconnected; thus, the decisions they make affecting the generation, transmission, and distribution of power have widespread effects on all consumers. Consequently, communication and cooperation among all power suppliers and delivery systems are essential to the smooth working of this industry.

No single fuel is capable of providing the energy to meet all of our nation’s electricity demands; therefore, many energy sources provide the fuel necessary to generate electricity. The combination of energy sources used is referred to as the generation or fuel mix. Electric companies use a diverse mix of fuels to generate electricity. Most of the company uses coal to produce electricity, others uses nuclear fuel, natural gas, hydropower, fuel oil, wind, solar and biomas.

Several factors influence a utility’s decision to use particular fuels to generate electricity. Chief among them are price, availability, and reliability of supply. The fuel choice also depends on whether the unit will be used continuously or only during peak usage times, its environmental impact, and necessary environmental controls.

Most utilities rely on a variety of fuels to generate electricity. A varied fuel mix protects the electric company and its customers from contingencies such as fuel unavailability, price fluctuations, and changes in regulatory practices. It also helps ensure stability and reliability in electricity supply, and strengthens national security. For example, since 1978 coal- and nuclear-based generation have increased significantly, while the use of oil has decreased by almost two-thirds. Recent advancements in gas-fired turbine technologies and the low price of natural gas have also resulted in increased reliance on gas as a fuel source for electricity generation.

Electricity is measured in units of power called watts. One watt is such a small amount of power, however, that the more commonly used measurement is the kilowatt, representing 1,000 watts. The higher the watt or kilowatt rating of a particular electrical device, the more electricity it requires.

The amount of electricity a power plant generates or a customer uses over a period of time is measured in kilowatt-hours (kWh). Kilowatt-hours are determined by multiplying the number of kilowatts required by the number of hours of use, and then dividing by 1,000. For example, if you use a 60-watt light bulb 5 hours a day for 30 days, you have used 60 watts of power for 150 hours, or 9 kilowatt-hours of electrical energy.

 Electricity Is Produced Around The Clock By Generators In Power Plants. The simplest type of generator has two main components: a rotating magnet called the “rotor,” which turns inside stationary coils of copper wire called the “stator.” When the rotor rotates through the magnetic field, it generates a flow of current through the copper coils of the stator. Generating plants must use some form of energy or fuel to turn the rotor.

Most electricity is produced by burning fossil fuels—coal, natural gas, and, to a much lesser extent, fuel oil. These fuels are burned in a boiler to turn water into steam. Under high pressure, the steam turns the blades of a turbine that spins a generator, producing electricity. In a nuclear plant, steam is produced by the controlled splitting of uranium atoms in a process known as nuclear fission. In a hydroelectric power plant, moving water provides the energy to turn the turbine blades. With wind turbines, the flow of wind turns the turbine blades, which then turn an electric generator. With solar power, sunlight is converted into electricity through solar cells that absorb the sun’s energy.

Electricity moves through a complex transmission system. It Must Travel From Power Plants Through A Vast Network Of Overhead Lines And Underground Cables To Reach Consumers.Transformers are located in substations near an electric generating plant. In much the same way that a pump builds up the pressure of water in a hose, transformers step up the electricity voltage to levels ranging from 69,000 to 765,000 volts. The voltage level depends on the distance the electricity must travel and the amount desired. From the transformers, electricity enters the transmission system. Transmission lines, which consist of heavy cables strung between tall towers, carry electricity to the point where it is needed. Electricity travels at nearly the speed of light, arriving at a destination at almost the same moment it is produced. 

When electricity leaves a power plant (1), its voltage is increased at a “stepup” substation (2). Next, the energy travels along a transmission line to the area where the poweris  needed (3). Once there, the voltage is decreased or “stepped-down,” at another substation (4), and a distribution power line (5) carries the electricity until it reaches a home or business (6).

 Step-down transformers located in distribution substations reduce the voltage of the electricity from transmission lines to lower levels so it can be carried on smaller cables or distribution lines. Smaller transformers on poles or underground further reduce the voltage so that it can be used by residential customers. Homes, businesses, and farms require 120- or 240-volt service. Industrial customers using large amounts of electricity ordinarily require higher service voltages.

 Electricity Has Unique Properties That Do Not Allow It To Be Stored Or Routed. Unlike oil or gas in a pipeline, electricity cannot easily be stored. It must be generated and delivered at the precise moment it is needed. To reach consumers, electricity must travel from a power plant through miles of transmission and distribution lines until it reaches its final destination where it will be used. Electricity travels through the path of least resistance. This path must be made of a material—such as metal—through which electrons can easily travel. Unlike telecommunications, electricity cannot be routed from one destination to another. Electricity will travel down whatever paths are made available to it but cannot be directed to go to a particular destination. Utilities have interconnected their transmission systems so that they may buy and sell power from each other and from other power suppliers, and to ensure reliability of service.

Electric Companies Meet Peak Consumer Demand By Keeping Additional Generating Capacity Available. Electricity must be produced when customers need it. Because electricity cannot be stored easily or economically, electric companies and other electricity suppliers must have enough generation facilities available to meet the maximum demand on their systems, whenever that occurs.

The electric load that electric companies and other electricity providers must supply is the sum of all customers’ demands. Because customer needs vary constantly, demand varies constantly, too. Heaviest demand usually occurs during the day from all sectors—industrial, commercial, residential, and transportation—and lowest demand during the night. Demand also varies with the seasons and with changes in the weather.

To ensure that there is enough electricity available to meet customer demand, some plants work around the clock, allowing electric companies and other power providers to generate a steady supply of electricity equal to the demand of their customers. Typically, companies use coal-based, hydro, or nuclear plants to provide this continuous service because they are cheaper to run for prolonged periods.

Pumped storage hydro, natural gas, or oil-based units are usually the units of choice for providing service for the hours of the day when demand hits its highest levels or peak. These peaker units may be started and stopped quickly, unlike coal- and nuclear-based plants.