Wildfire risk posed by an electrical substation.

Abstract

Wildfires have caused significant damage in Chile in recent years, with electrical infrastructure being a potential ignition source for these events. This study describes a methodology for estimating the wildfire risk associated with an electrical substation located in the Wildland–Urban Interface of Valparaíso, Chile. Wildfire risk is defined as the product of the probability that a fire originates in the substation and the probability of ignition of the surrounding vegetation fuels. The first probability was determined using an event tree, while the ignition probability was estimated from experimental data relating ignition to heat flux. Flame height and intensity were estimated using simplified models developed for spill fires. The probability of a fire originating in the substation was estimated at 1.92 × 10⁻⁷ events/year, resulting in a wildfire risk ranging from a value close to zero up to 2 × 10⁻⁷ events/year. This methodology provides a comprehensive interpretation of risk, considering both the probability of fire occurrence and the propensity of nearby vegetation fuels to ignite under such conditions. It therefore represents a useful tool for quantitatively evaluating wildfire risk in industrial infrastructures and for proposing appropriate mitigation measures.