Why Does Power Go Out During Storms?

Heavy rain, lightning, strong winds and other types of severe weather cause power outages by knocking down power lines, blowing objects into overhead lines, flooding power-related equipment, or damaging insulation, among others. Most storms bring strong winds along with them, which causes trees to sway and branches to snap. When a tree branch comes in contact with the high-voltage power lines, the power is automatically cut, and then restarted when the contact ends. This is to prevent the electric current from being discharged and wasted. If a branch snaps and falls onto a power line, the power will remain off until the problem can be resolved. In some cases, the wind can be so bad that it will blow power lines down, or an entire tree will fall across the lines, pulling them down. This is why municipal crews spend a lot of time cutting trees back when they begin to encroach on nearby power lines. Aside from the wind, precipitation is also potentially disastrous for power lines. Heavy and continuous rains can damage the insulation elements (e.g., bushings and switches) and cause a blown fuse and power loss.