In response to your statement about PG&E’s long neglected outdated infrastructure. Since the late 1990s, PG&E has invested billions in infrastructure upgrades. PG&E has state-of-the-art technology across its entire power grid. An insulated high voltage wire called “tree wire” can be effective in certain circumstances. It is certainly not a substitute for a well-designed underground system.
The problem with a tree wire system is that it always has uninsulated sections to accommodate connections and switching devices. The tree wire is supported by utility poles and crossbeams. Posts and rails cannot stop a falling tree. They cannot support the additional weight produced by ice and snow. They cannot stop the destructive power of high winds and lighting. All of these problems with the tree wire system have the potential to start a fire.
The new tree wire has good insulation value. Over time, this insulation value can change. Outdoor temperatures, internal wire temperatures, wire expansion and contraction due to amperage fluctuations, and air pollution all cause tree wire insulation to degrade. Remember we are talking about tens of thousands of volts and hundreds of amps flowing under that damaged insulation.
Initially, a high voltage underground system takes time and money, but in the long run it will be easier to maintain and be a better system to prevent fires. As a retired construction lineman, I know PG&E wants to keep your lights on and your safety.
—D. Nicholas Evans, Chico