Skip to Main Content

Renewable Energy Industries: A Research Guide

Electric Power Sector and Power Grid

Engineering and Research Center, cartographer. Principal power facilities; Western United States, existing and under construction. 1972. Library of Congress Geography and Map Division.

The vast majority of energy produced by renewable sources goes towards electricity. This section of the guide provides resources for learning about the electric power sector and electrical grid in the United States. The U.S. has three primary transmission grids that create a network to connect local girds to increase reliability: the Eastern Interconnection, the Western Interconnection, and the Electricity Reliability Council of Texas (ERCOT), which is also called the Texas Interconnection.1 There are also electric power marketplaces, which distribute electricity from power producers to customers. These marketplaces can be independent system operators (ISOs) or regional transmission organizations (RTOs). Because they function similarly, they are often grouped together, and are also known, especially in Europe, as transmission system operators (TSOs).2 In addition to the wholesale and retail energy markets, some ISOs and RTOs also have capacity markets, where power generators are paid to maintain generation capacity in reserve, to increase grid reliability.3 ISOs and RTOs cross state lines, so they are regulated by the Federal Energy Regulatory Commission (FERC). In 2006, FERC authorized the North American Electric Reliability Corporation (NERC), a non-profit non-governmental international regulatory authority, to be the national Electric Reliability Organization of the United States. NERC ensures the reliability and security of the electric grid for the contiguous United States, Canada and the northern portion of Baja California, Mexico.4

Smart grids, microgrids, and distributed generation (or distributed energy resources) are features often discussed in regards to modernizing the electrical grid, and they provide opportunities for renewable energy producers to enter the energy market.5

Overview of the Electric Power Grid

The following online resources are useful starting points for understanding the U.S. power grid, starting with Congressional Research Service Reports:

The U.S. Energy Information Administration (EIA) releases short energy news articles in their publication Today in Energy. The following two articles talk about the electric grid, but more information about the electric power sector can be found by doing a keyword search or browsing by tag.

Additionally, government agencies, organizations, and energy journalists have written helpful overviews explaining the power grid. Some useful starting points are linked below.

Additional Resources

The following online resources provide information on electric power sector, its history, and new technologies.

The following materials link to fuller bibliographic information in the Library of Congress Online Catalog. Links to additional online content are provided when available.


  1. U.S. Department of Energy, Hydropower Vision: A New Chapter for America's 1st Renewable Electricity Source (July 2016), 84: Back to text
  2. David Roberts,"Clean energy technologies threaten to overwhelm the grid. Here’s how it can adapt," Vox, (Nov 11, 2019). See also definitions and descriptions of end use sectors: U.S. Energy Information Administration, "Use of Energy Explained," May 14, 2021. Back to text
  3. American Public Power Association, Wholesale Electricity Markets and Regional Transmission Organizations External. Back to text
  4. David Nevius, The History of the North American Electric Reliability Corporation External, (NERC, 2020): 85. Back to text
  5. Richard J Campbell, The Smart Grid: Status and Outlook, CRS Report R45156, Congressional Research Service, (April 10, 2018).& Back to text