High above the ground, Zip Zap is one of billions of electrons racing through a high-voltage transmission line. Rumor has it that a wildfire is roaring nearby. Most electrons fear the heat, but not Zip Zap. She is a thrill-seeker. She is tired of the daily grind — running from the power plant to a toaster and back. She dreams of having a big breakout moment where she starts a fire or shocks someone.

Her strategy is to try to escape in this part of the race: Once she gets to the lower lines, they will be covered in plastic insulation. The high-voltage lines are bare metal, and the surrounding air itself is the insulation keeping her from veering off the track.

Zip Zap knows her race could end abruptly. If that’s going to happen, she hopes it’s because of what Californians call a Public Safety Power Shutdown (PSPS) — when the utility company cuts the flow before the fire arrives to thwart her ambition to create mayhem. If the flow is turned off at the source, the lines stay intact, and Zip Zap only has to suffer a long boring wait. If the fire hits first and snaps the line, the race track is destroyed, and her racing career is over.

But, so far, so good.

As the line gets close to the fire, the air turns into an oven. Zip Zap feels the metal wire beneath her begin to expand and stretch. This is thermal expansion. The once-tight wire sags and droops into a long, lazy curve. Zip Zap accelerates down the dip, watching the ground get tantalizingly close. The sagging line is now a major safety violation, and is inches away from touching dry brush, almost granting Zip Zap her wish of starting a fire. Almost.

Then comes the big wipeout! Thick soot and ash have coated the wire and, more importantly, the ceramic insulators. Usually, these insulators act like “DO NOT ENTER” signs, keeping Zip Zap and other electrons from running onto the wooden or metal poles. But the soot creates a dirty, conductive bridge over the ceramic.

Sparks fly in all directions. Electrons skitter onto the poles. It is a free-for-all, with every electron looking for a way out. Zip Zap tries to get into the fray, but momentum shoves her back onto the main line.

Disappointed, she almost misses her big break. The air around the wire is no longer clear; it is a smoky vortex filled with carbon and ash. This mixture is so intense that it ionizes, the smoke enables the very air between the wire and the trees to conduct electricity.

Seized by the attraction, Zip Zap joins a massive strike force of electrons. Together, they arc through the smoky haze like a localized bolt of lightning. They slam into a pine tree with a deafening crack. Bark explodes, branches ignite, and sparks spew over the forest floor.

Zip Zap’s wildest dream is fulfilled: She goes out in a spectacular flash of fire-starting glory rather than meekly slipping out a kitchen outlet.

What can you do?

BEFORE the fire: Ensure that trees are trimmed from around power lines. Utility companies often do this for free. Or hire professionals who have the expertise and equipment to work safely around electrical lines.

DURING the fire: Stay safe.

AFTER the fire (and at all other times): Report damage to power poles and downed lines. Stay clear of downed and low-hanging power lines — at least 30’ (about one city bus length)!

RIGHT NOW: Make a donation to help Creative Crisis Leadership turn complex science into simple, life-saving knowledge!

Sources

1. Wildfire Reliability | California Public Utilities Commission
2. Extreme Weather and Climate Vulnerabilities of the Electric Grid | Oak Ridge National Laboratory
3. Knowing what to do around a downed power line could save your life | San Luis Valley REC