Submitted by Holly Eagleston, Founder of Firescape
According to Moody’s a year after the 2025 Los Angeles fires, insured losses amount to $25–30
billion and the subrogation questions surrounding the Eaton Fire are still unresolved, pending a
determination of cause. That single unanswered question, how the fire started, will govern how
billions of dollars in losses are ultimately allocated between carriers, a utility, and a state wildfire
fund.
For claims professionals, this is the pattern worth internalizing: in a utility-associated wildfire,
the entire financial resolution turns on the mechanics of ignition. Understanding the mechanics
of what actually causes electrical equipment to start a fire, and what utilities are doing to prevent
it, is no longer specialized knowledge reserved for engineers and mitigation planners. It has
become core competency for anyone who handles wildfire exposure.
How the Grid Starts Fires
Utility-associated ignitions are not random events. According to CPUC ignition data, the number
one cause of ignitions is tree-to-wire contact. Other ignition modalities include equipment
failure, and arcing from wildlife or debris.
Vegetation contact is the leading cause. Studies of California ignitions attribute more than half
of utility-related fires to conductors coming into contact with vegetation. This happens in two
ways: a tree or limb falling into an energized line, and a conductor swinging out into nearby
vegetation under high wind. A branch bridging two conductors can sustain high-temperature
arcing which showers sparks on the ground below.
Conductor slap occurs when power lines, engineered to maintain clearance from one another,
are driven together by wind or fault forces. The contact produces high-energy arcing, causing
sparks capable of igniting ground-level fuels.
Equipment failure either from a pole failure or the components on the pole. A cracked insulator
can allow current to arc directly onto a wood pole. A failing transformer can overheat or explode.
Aging apparatus under rising load produces sparks it did not produce when it was new.
Critically, these mechanisms tend to be weather-dependent. The same high-wind conditions that
make an ignition most likely to catch and spread are precisely the conditions that make
conductors sway, vegetation fall, and faults occur. Grid ignition risk and fire-spread risk can peak
at the same moment.
The Mitigation Toolkit
Utilities deploy vegetation management, hardening, and as a last resort, Public Safety Power
Shutoffs. But one of the highest-leverage, lowest-cost tools lives inside the protective relays on
every circuit.
Normally these devices are tuned for reliability. Because many faults are momentary, reclosers
trip and then automatically re-energize, often several times, assuming the fault has cleared. In
fire weather this becomes dangerous: over dry fuel, each reclose attempt showers hot particles
and sustains arcing — in effect, striking a match repeatedly over tinder.
Utilities reconfigure their settings for fire season, in programs known as Enhanced Powerline
Safety Settings or Sensitive Relay Profile, collectively fast-trip protection. Two adjustments do
the work: interrupting power within a fraction of a cycle at the first sign of a fault, and disabling
automatic reclosing so a tripped line stays de-energized until a crew inspects it.
The catch is reliability. A more sensitive circuit trips more often, meaning more outages. The
outage may be extended, since the line cannot re-energize until inspected. Applied
indiscriminately, fast-trip settings degrade service and create their own risks. The entire value of
the strategy rests on precision: the right settings, on the right circuits, at the right time, relaxed as
soon as the weather allows.
Technology That Sharpens the Decision
Weather shifts hour by hour across a territory spanning thousands of square miles. Decision of
where to enact settings should also be based on wildfire spread modeling, and consequence
modeling. Solutions such as Firescape GridWatch platform, offers dynamic, circuit-level
picture of where risk is elevated and helps utilities determine when and where to apply
mitigation settings.
The technology to prevent a large share of grid-caused ignitions already exists, and it cuts them
roughly in half where deployed. What is missing is not capability but adoption. These tools
remain concentrated among a handful of large western utilities, while thousands of cooperatives,
municipal systems, and utilities in newly fire-prone regions have yet to implement them. Every
one of those gaps is a future claim waiting to happen. The claims industry has as much stake as
anyone in seeing prevention adopted broadly, because the alternative to prevention is higher
likelihood of catastrophic wildfire.
