Power Grid Basics
The power grid is the complex network of power sources, transmission lines, and distribution lines that brings electricity to your home.
The U.S. power grid is often called “the greatest engineering achievement of the 20th century." It is made up of millions of miles of power lines delivering different energy resources to communities around the country.
Power Grid Reliability
Many grid services are required to maintain reliable power, even during unexpected outages. These services are provided at different timescales and serve different purposes on the grid. As more advanced energy technologies are added to the U.S. power system, there is increased interest and requirements for them to provide essential reliability services during normal operation and during and after major power disruptions.
Learn about different aspects of grid operations and the ability of the power system to reliably keep the lights on.
Resource Adequacy
Supplying enough electricity in the right locations to keep the lights on during all hours of the year.
Operational Reliability
Balancing supply and demand in real time and rapidly responding to unexpected events.
Power System Resilience
Quickly responding to and recovering from power disruptions.
Power System Protection
Protecting the power grid from faults, or abnormally high or low electrical current.
Fact Sheets
Learn more about the reliability of the power grid:
Maintaining Grid Reliability – Lessons From Renewable Integration Studies (2024)
Reliability of the Current Power Grid (2024)
Causes of Three Recent Major Blackouts and What Is Being Done in Response (2024)
Maintaining a Reliable Future Grid With More Wind and Solar (2024)
Check out all our fact sheets on the power grid.
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Last Updated Aug. 27, 2025