Year-round inspections, repairs and upgrades to our energy grid are among the wildfire mitigation measures we use to ensure safe, effective operations.
“Safety is our highest priority and we have multiple measures in place to reduce the risk that wildfires might present to the public, while maintaining reliable service for our customers,” said Larry Robinson, Director of Engineering.
Some of the measures we use to guard the grid from wildfire risks include:
Inspection and vegetation management. We inspect and reinforce our network of transmission and distribution lines throughout Arizona. Employees continually conduct visual inspections of lower-voltage distribution facilities to identify equipment in need of maintenance and vegetation in need of trimming. Crews work throughout the year to trim trees and other vegetation that could create fire risks.
Near Nogales, UniSource crews perform ground patrols every year to inspect distribution equipment in forested areas. Our 138 kilovolt (kV) transmission facilities are patrolled by helicopter twice a year.
In the Kingman and Lake Havasu City areas, UniSource’s 69 kilovolt (kV) lines and remote lower-voltage distribution lines are patrolled by helicopter once a year.
“Clearing vegetation away from our equipment helps reduce the chance that a wind-blown branch could contact power lines and start a fire,” Robinson said.
Fire-resistant systems. We’ve improved the grounding and bonding procedures of power pole hardware to reduce ignition risks. Our System Control operators monitor our local energy grid around the clock to identify faults and de-energize equipment as needed to support wildfire mitigation and fire suppression efforts.
Emergency planning and situational awareness. UniSource participates in wildfire training and preparation efforts with neighboring utilities, public agencies, tribal offices, private landowners and others before and during wildfire events. If wildfires approach our systems, employees are assigned to coordinate with firefighting agencies and local officials at incident command sites. Employees monitor state and federal wildfire and emergency management websites to identify potential threats near UniSource systems.
Despite our robust wildfire mitigation efforts, extreme summer heat and high winds can increase the risk that power lines might spark wildfires, particularly in remote, dry areas.
Beginning this summer, in dangerous weather conditions, we may need to proactively shut off power to a very limited number of customers in certain areas that are risk-prone for wildfire. These shut-offs would temporarily interrupt electric service until conditions improve. This measure, which UniSource would only use as a last resort, is known as a public safety power shutoff (PSPS).
After a comprehensive analysis of weather, vegetation, wildfire history and fire spread modeling in regions we serve, we’ve determined that about 750 electric customers in Santa Cruz County and about 350 electric customers in Mohave County could be subject to PSPS events. Our review included engagement with emergency response coordinators and first responders. The vast majority of our 105,000 electric customers will not experience a service interruption due to PSPS events during periods of extreme wildfire risk.
For more detailed information on such events, visit uesaz.com/wildfire-safety.
