Brownout vs. Blackout

Demand for power can become greater than the amount being generated—such as during extreme low temperatures in the winter, a heatwave in the summer, or equipment failure at generation plants. The system can become overloaded by high usage, and brownouts may become necessary to avoid blackouts. Below are more details about brownouts and blackouts.

*URECC will take all possible measures to avoid brownouts, even to the extent of temporarily shutting down circuits to prevent low-voltage damage to members’ electronics, HVAC units, and other electric-powered products.

• What’s the Difference Between a Blackout and a Brownout?
  A brownout is caused by high electricity demand that is near or above a utility’s production capacity. When this occurs, the utility may reduce the flow of electricity to certain areas to prevent a blackout. A blackout is a large-scale service interruption that can happen as a result of severe weather or equipment failure at power plants.
• What Causes a Brownout?
  When demand nears or exceeds the utility’s maximum production capacity, the utility may intentionally throttle the flow of electricity in certain areas. These intentional brownouts may last from a few minutes to several hours—until demand likely decreases and the utility can restore full power. While less common than severe weather events, brownouts can also occur spontaneously due to damage or malfunctions in the grid or nearby plants.
• Why Do Blackouts Happen?
  A blackout is when electrical service stops entirely. The term “blackout” typically refers to large-scale interruptions, while smaller events like transformer failures are often called “power outages.” Major blackouts often result from severe weather or equipment failure at generation sites.
• What Is a “Rolling Blackout”?
  A rolling blackout is a deliberate process used by utilities—similar to a planned brownout—to temporarily relieve pressure on an overtaxed grid. These short-term outages are rotated across multiple areas to prevent a wider-scale blackout. They are typically announced, though often with short notice. (Note: Rolling blackouts are different from “planned outages,” which are scheduled well in advance for maintenance.)
• What to Do During a Power Blackout or Brownout?
  If you notice dimming lights or other signs of a brownout, unplug computers and sensitive electronics. Most appliances can handle low voltage, but electronics may be damaged. During a blackout, consider unplugging devices as well—while the outage itself won’t harm them, the surge when power returns could.
• Who to Call in a Power Blackout or Brownout?
  After unplugging electronics, contact your local utility to confirm if the brownout is grid-related. If not, it may be a home issue—call an electrician. For a blackout, report the outage to URECC and check for restoration updates. Stay informed by signing up for real-time alerts via the URECC SmartHub app.

Blackouts and brownouts are rare, but understanding what they are and how to respond is key to minimizing the inconvenience.