Electricity Basics

What Is Electricity?

People use electricity every day — to charge phones, to power computers, to turn on lights, to cook dinner, and to brew that morning cup of coffee.
Electricity is the flow of electrical charge. Homes, buildings, and businesses get electricity through an interconnected system that generates, transmits, and distributes electricity – also called the grid.
GENERATION: Electricity is produced when certain forces (mechanical, magnetic, heat, or light) interact with energy resources — sunlight, wind, water, natural gas, coal, oil, nuclear. Various processes convert the potential energy from these resources to electric current, which is the movement of charged particles.
TRANSMISSION: Electric current then moves to an interconnected group of power lines and other equipment. These lines move electricity from its source, often transmitting high voltage electric current across great distances.
DISTRIBUTION: Devices called transformers then reduce the voltage of the electricity and move it to another set of lines and equipment that connect directly to the homes and businesses in your community.
The electric network, including generation, transmission, and distribution lines

What Are the Sources of Electricity?

Power generation sources in US in 2016

2016 US electric generation sources

Sources of public power generation in 2016


Availability of Electricity

Some sources of power can be ramped up and down fairly easily, while others must run continuously. Continuously operating plants are also called “base load resources” and plants that are used only when energy use increases are called “intermediate” or “peaking” resources. Renewable sources generate electricity only when there is sufficient energy, such as from the wind or sun, and in the absence of associated storage capacity, are considered “intermittent” or “variable” resources. 


Where Electricity Travels

The electric transmission network in the United States is organized into three interconnections – large grids that operate in sync and are carefully coordinated to prevent widespread blackouts. These interconnections effectively set boundaries for where electricity flows across the U.S.

Map of US interconnections

Buying and Selling Electricity

Power suppliers can sell the power they generate or transmit in wholesale power markets. The Federal Energy Regulatory Commission regulates this wholesale sale of electricity. In an effort to increase transmission access to buyers and sellers, FERC encouraged transmission infrastructure owners to hand over operations of transmission facilities to regional transmission organizations, also called independent system operators. These RTOs/ISOs provide interstate transmission services and operate wholesale power supply markets. Not all regions of the country have an RTO or ISO, and there are variations in regional power supply and transmission markets.


What is the Smart Grid?

The smart grid is a developing network of transmission lines, equipment, controls, and technologies working together to respond immediately to electricity demand.


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