Last updated on: 1/29/2009 | Author:

What Is the Electricity Grid?

General Reference (not clearly pro or con)

Barry K. Worthington, Executive Director of the United States Energy Association (USEA), and David Ropeik, Consultant in Risk Perception and Risk Communication at Ropeik and Associates, in their June 2001 article “America’s Power Needs – How the Grid Powers a Continent,” for World and I, provided the following definition of the electric grid:

“The Grid is the giant network of high-voltage power transmission wires- -those big ones up on those tall construction-set towers–that covers the entire United States and much of Canada. These wires are all interconnected at hundreds of substations, so power companies can buy and sell ‘product’ from each other. Effectively it’s a single machine to distribute electricity, stretching 3,000 miles from east to west, and 3,000 miles from north to south.

The Grid has three main sections. The eastern part connects everything from the Rockies to the Atlantic, and from Florida up into Canada. The western network connects everything west of the Rockies from Mexico up to Canada. Most of Texas is on a grid of its own. (Back in the 1930s, Texas utilities didn’t want to deal with interstate government controls.) For control purposes, the Grid is broken down into 150 smaller subsections, so things can be monitored on a more local basis.

But those subsections are only organizational. The wires are all interconnected. It is technically possible to light up a light bulb in Seattle with a watt that was generated in Tallahassee.”

June 2001

The Global Energy Network Institute (GENI), a non-profit organization conducting research on possibilities for a global electric energy grid, in a section of its website,, titled “National Energy Grid Map Index,” provided the following map of the different regions in the US electric grid (which is sometimes also referred to as the energy or power grid):

Source: “National Energy Grid Map Index,” Global Energy Network Institute (GENI) website (accessed Dec. 10, 2008)

Dec. 10, 2008

The Energy Information Administration of the US Department of Energy, in the “Glossary” section of its website (accessed Dec. 10, 2008), provided the following definition of the electric grid:

“A system of synchronized power providers and consumers connected by transmission and distribution lines and operated by one or more control centers. In the continental United States, the electric power grid consists of three systems: the Eastern Interconnect, the Western Interconnect, and the Texas Interconnect. In Alaska and Hawaii, several systems encompass areas smaller than the State.”

Dec. 10, 2008

Overdomain, LLC, Endecon Engineering, and Reflective Energies, in a Sep. 2003 report titled “California Interconnection Guidebook: A Guide to Interconnecting Customer-owned Electric Generation Equipment to the Electric
Utility Distribution System Using California’s Electric Rule 21,” for the California Energy Commission and available on its website, wrote the following:

“The electric grid is broadly divided into two systems: the transmission system that transfers bulk power at high voltages, from power plants to utility-owned substations and a few very large customers, and the distribution system that delivers power at medium and low voltages from the substation to the majority of customers.”

Sep. 2003

The Massachusetts Technology Collaborative, Massachusetts’ development agency for renewable energy, in a section of its website titled “Electricity Distribution” (accessed Dec. 11, 2008) provided the following definition of electric grid:

“The electric grid delivers electricity from regional power plants to local customers…

[T]he utilities that keep the grid running continually face challenges in maintaining the grid’s capability to deliver reliable electric service to all customers. Demand for electricity can sometimes exceed the grid’s capacity, particularly in high-density areas and areas where development is occurring faster than new distribution lines can be built. When demand exceeds the grid’s capability, the grid becomes congested, or unable to deliver the amount of electricity needed.”

Dec. 11, 2008