Electric utilities work hard to prevent power outages, but when 1 occurs, there is a clear plan to restore power quickly and efficiently.
When the power goes out, utility staff springs into action to bring back the lights as quickly and safely as possible. Office staff determine the extent of the outage, while line crews brave the elements to check damage to the grid and make repairs.
Restoring power can be complex. The North American power grid— comprised of multiple regional grids—is arguably the world’s largest machine, with substations, power lines, and other infrastructure webbing out across the landscape to bring electricity to homes and businesses. To efficiently restore power across the grid, utilities typically start with the equipment that serves the most people and work down the line until all the lights are back on.
Transmission Lines
Transmission lines deliver power from electricity generators to a local utility’s grid. Serving as the highways of our electric grid, high-voltage transmission lines cover huge distances. They are often controlled by organizations such as Bonneville Power Administration or a transmission utility.
These large towers and their lines rarely fail—typically only in the most severe weather. If they do, many communities will lose power. Transmission lines must be repaired before power can be restored locally.
Substations
Substations are distribution hubs where utilities receive and send electricity. Substations typically serve local communities.
When there is an outage, utilities check to see if the issue is with transmission lines bringing in electricity, with the substation itself, or with the power lines moving electricity to homes and businesses.
Distribution Lines
Branching out like local roads, distribution lines take electricity from substations to towns, neighborhoods, and other small groups of consumers.
Because distribution lines are spread out like a web, rather than being condensed in 1 place like a substation, finding the cause of an outage along a distribution line can take more time. Often, utility line crews must patrol the lines to find the cause of the outage, such as a fallen tree that knocked down power lines.
Service Lines
Service lines connect distribution lines to transformers that serve individual houses, businesses, and other consumers.
If 1 home lacks power while lights are on in the rest of the neighborhood, the issue could be with the service line. If multiple homes have issues, it could be an issue with a transformer or distribution line.
During an outage, substations and distribution lines serving full communities are prioritized before repairs to individual service lines.