Southern California Edison unveiled a $582 million program Monday that would step up wildfire safety measures, including a plan to replace nearly 600 miles of its power lines with insulated wire.
In complying with wildfire mitigation plans spelled out in Senate Bill 901, officials for the utility on Monday filed details of its Grid Safety and Resiliency Program with the California Public Utilities Commission.
Edison plans to replace nearly 600 miles of overhead power lines in high fire risk areas with insulated wire by the end of 2020. The move would mark the first large-scale deployment of insulated wire in the U.S. designed to reduce wildfire risk.
While up to 10 percent of wildfire ignitions in California are from power lines, within Edison’s service area more than half of ignitions associated with distribution lines are caused when objects such as metallic balloons, tree limbs and palm fronds come into contact with power lines.
While bare, uninsulated wire meets California state standards and is widely used by utilities across the country, insulated wires can significantly reduce the potential for ignitions resulting from contact with foreign objects.
In addition, insulated wires provide the greatest overall value compared to other mitigation measures such as undergrounding lines.
The utility also wants to make its poles safer. The new poles would be made from “layers of strong glass fibers bonded with epoxy resins.
Under the plan, where appropriate and whenever utility poles are to be replaced, they will be replaced with fire-resistant composite poles that would support the increased weight and diameter of the insulated wire.
Edison also plans to replace about 3,400 miles of overhead line with insulated wire between 2021 and 2025.
Funding for that work would be included in future general rate case requests.
The utility infrastructure would be further improved under the new plan with the installation of fuses and circuit-breaker type devices called remote-controlled automatic reclosers.
Edison is installing 15,700 “current limiting fuses” which would interrupt current more quickly and avoid the potential creation of their own heat source during fuse operation when compared to traditional, industry standard fuses.
The move promises to limit the number of customers affected by an outage.
Use of “reclosers” would stop affected circuits from automatically re-energizing so that work crews can physically inspect the lines before they are re-energized. (The Signal, 9/10/2018)