The first power pole in California was erected in the 1880s, almost around the time when the light bulb was invented by Thomas Edison. Today, the state has a web of fragile and fire-triggering lines that run up to a whopping 210000 miles. According to the California Department of Forestry and Fire Protection, four of the smaller fires that took Northern California in its grip last year were caused by power lines. California’s fire investigators have held Pacific Gas & Electric responsible for some of the catastrophic Northern California wildfires in 2017 that killed 44 people and lead to property losses of more than $3 billion. If the allegations are proved right, the company might end up paying $9 billion to cover the damages.
With power lines now under scrutiny as the suspected culprit behind California wildfires, the deadliest wildfires have ignited some grave questions. Is the country’s electrical grid is due for a costly overhaul? What measures should be taken by the power companies to prevent wildfires from wreaking havoc again?
Power Lines and Fires – What’s the Connection?
Power lines have regularly topped the list of the biggest culprits behind California wildfires for the last several years. In 2015, power lines reduced 149,241 acres of forest land to ashes. This is more than twice the amount from any other cause.
Regulators have slapped the state’s investor-owned utilities with hefty fines related to wildfires, including:
- $37 million for the 2007 Malibu fire (Southern California Edison)
- $14.4 million for the 2007 Witch, Rice and Guejito fires (San Diego Gas & Electric)
- $8.3 million for the September 2015 Butte Fire (Pacific Gas & Electric)
While the investigating agencies are still investigating whether the Northern California fires were sparked by the power lines, dangers these age-old power lines pose to the forest and precious lives cannot be ignored.
As a matter of fact, power lines cause fires through various mechanisms:
Downed lines: Power distribution systems are equipped with protective devices, like fuse and circuit breakers that detect short circuit fault conditions and minimize damage to the system. In some cases, a single energized line conductor breaks and falls to the ground. The surface contact resistance causes a restricted flow of the fault current. The current is too low to blow a fuse or trip a circuit breaker. A line with this fault may remain energized for a long period of time, causing high-energy and high-temperature arcing, which could ignite anything in its vicinity.
Conductor slap: Power lines are designed in a way that sufficient gap exists between conductors to keep them from contacting each other. But in some rare conditions, conductors slap together, creating high-energy arcing and ejecting hot metal particles, which are capable of starting a fire.
Recurring faults: Some power line faults can occur multiple times due to conductor slap, equipment failure, vegetation etc. Such repetitive faults can lead to fires.
Component failure: A typical power line circuit may have hundreds or even thousands of components which eventually fail with time. Before they fail, they undergo a pre-failure period during which they continue to serve load. This pre-failure period often involves arcing and sparking at levels that are so small that they often go undetected. Under favorable conditions these may lead to fires.
Preventing Such Mishaps in Future
In order for California to prevent such catastrophic wildfires in future, there is a need to find measures to make existing power systems safe. Here are some measures that can be taken:
- Undergrounding wires: Undergrounding is a solution that the power companies are now considering to prevent fires in future. Underground power lines do not get swayed away by the wind. The tree branches blown away by wind also can’t hit them. They can, therefore, prove to be an ideal solution for wildfires in places like California, which has a history of wildfires sparked by overhead power lines tangling with trees.
- Insulating the lines and wires: Overhead transmission lines may be insulated from their support towers by phenolic, ceramic or other insulating materials. The high tension wires are insulated from each other and the ground by air due to its low cost and easy availability. Underground transmission cables can be insulated using a variety of materials, including oil.
- Retiring old wooden poles: Replacing wooden poles with steel poles will ‘fire-harden’ the lines in the areas that are prone to wildfires. Moreover, steel poles have relatively lower greenhouse gas emissions and impact on energy resources.
- Turning off power when the wind picks up: Deliberate, pre-planned power outages can help prevent fires when there is extreme wildfire risk. Deliberate power outages during intense windstorms have already been practiced by San Diego Gas & Electric Co. in the past. It may cause inconvenience to the customers but can surely save them from catastrophic consequences.
- Biomass energy: Biomass energy can help reduce greenhouse gas emissions and prevent wildfires by promoting forest fuel reduction. As it is, the biomass waste is commonly disposed of by burning, which further leads to pollution and warming of the environment. Using biomass for fuel can help curb both the problems. In fact, California, as a part of its ambitious renewable energy goals, is making a push to use forest fuels in biomass energy power plants.
California is the world leader when it comes to energy technology. The solutions listed above are well within the reach of one of the world’s most advanced and innovative economies. All that is required is the vision, optimism, and industry leadership to help reduce wildfire occurrences. There is a need to think and work in ways that are safe, clean, and reliable in the fight against wildfires and in the pursuit of a clean energy economy.