PG&E is using both helicopters and drones to perform transmission line inspections in Marin and Sonoma counties.
The utility's System Inspections Program accelerates inspection cycles beyond compliance regulations to keep up with increased wildfire risk. The accelerated program is one of several measures the utility has taken to keep its systems safe amid extreme wildfire conditions; others include enhanced vegetation management and electrical system "hardening," a general toughening of various equipment to better withstand the tougher conditions, PG&E says.
PG&E has notified residential and business customers along several transmission lines throughout both counties of the drone and helicopter flights via postcards or automated phone calls. The inspection areas for the weeks of Aug. 31 and Sept. 7 are along lines that run through:
- Marin County: San Rafael, Novato, Sausalito and Bolinas
- Sonoma County: Petaluma, Lakeville, Fulton, Santa Rosa, Windsor, Healdsburg (Fitch Mountain), Sonoma, Boyes Hot Springs and Agua Caliente
The ongoing program serves to find and fix potential risks to the safety and reliability of PG&E's power delivery system. The company is prioritizing work in areas of extreme (Tier 3) and elevated (Tier 2) wildfire risk as defined by the California Public Utilities Commission (CPUC) High Fire-Threat District Map. Equipment along electric transmission lines located in Tier 3 and Tier 2 areas will be evaluated more frequently, while infrastructure in non-high fire-threat areas will be inspected at least every six years.
In 2020, the company plans to inspect more than 15,000 miles of its electric lines. That includes all lines in Tier 3 areas and one-third of all lines in Tier 2 areas. Inspectors are looking at all components of PG&E assets, including cross-arms, insulators and footings, along with critical electrical components and equipment.
Inspectors document findings through high-resolution images, which are reviewed by dedicated teams experienced in system maintenance, engineering, construction and maintenance planning to evaluate identified conditions.
All the highest-priority conditions found through inspections will be promptly repaired or made safe. Repairs for all other conditions are scheduled for completion as part of the company's routine work execution plan.
Weather permitting and barring maintenance issues, flights will occur Monday through Saturday from 7 a.m. through 6 p.m. over the next couple of months.