Mother Nature vs. the Electric Grid

 

During certain types of weather events, we often expect outages. But what actually causes equipment to fail when Mother Nature roars? Here are a few examples (although not an exhaustive list).

Rain

Heavy rain mixed with dust can get inside unknowingly cracked insulators (which hold the wires on top of the poles). The electricity then “tracks,” meaning it moves along the wet, dirty wooden crossarm to a good ground source (ground wire or guy wire) until it catches the pole on fire. Similarly, an osprey (or other large bird) will drop sticks and conductive debris to build a nest between wires. When the nest gets wet it can conduct electricity and cause a fire – this is a big reason why we often relocate large nests, for both safety of the animals and reliability of the system.

It may seem odd to say that rain causes fires, but that’s often the case because the dirty water conducts electricity very well.

Wind

Aside from the common tree or branch broken in the wind and falling on lines, other things can de-energize lines, too. We’ve seen nests, kites, tarps, roofing, orchard foil, trampolines or other unsecured items cause outages. This is one of the reasons it’s important to keep poles and lines clear.

Ice/Snow

Picture that frosty buildup on a metal pole that you would never put your tongue on – it builds up on our wires and other infrastructure, too. This “ice loading” can snap our wires under its weight, or make them extremely fragile if something else hits them (like a tree branch). Some ice and snow is ok – the lines can take it. But too much, especially on older lines, can cause failures. Heavy ice loading mixed with wind is a bad combination.