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Fortifying the electric grid against the threat of wildfires has never been more important. Research shows that U.S. wildfires impacted an average of 6.8 million acres per year over the past decade. And so far in 2020, more than 32,000 wildfires have already burned nearly 2.2 million acres.
Although wildfires are naturally occurring, I believe utilities can strengthen distribution systems to reduce risk. In response to fires over the past four years, the California Public Utilities Commission (CPUC) has significantly expanded its fire protection codes and standards.
Utilities the world over are developing similar strategies and mitigation plans to reduce wildfire risk. The reality is that updating transmission and distribution systems to combat wildfire risk is a complex effort. Equipment manufacturers can help, specifically by designing and testing solutions in close coordination with the California Department of Forestry and Fire Protection (CAL FIRE).
CAL FIRE is leading the way to help utilities strengthen wildfire mitigation efforts with confidence. Although the organization’s guidelines may only legally apply to California utilities, wildfires occur more frequently on the East Coast — making CAL FIRE framework an extremely relevant template for utility risk management programs across North America.
In the late 1980s, California’s building code became unified under the California Building Standards Code – otherwise known as Title 24 of the California Code of Regulations. Part 9 of Title 24 is known as the California Fire Code. It establishes minimum requirements and aims to safeguard the public from fire hazards.
From my perspective, a crucial aspect of the California Fire Code is the California Power Line Fire Prevention Field Guide. This document outlines procedures to minimize the risk of catastrophic wildfires caused by electrical power lines and equipment. The field guide also details testing processes and a list of qualified equipment that meets CAL FIRE exemption requirements. An updated draft was recently published in 2020.
For example, the guide provides Power Line Clearance Requirements for any organization that owns, controls, operates, or maintains any electrical transmission or distribution line upon any mountainous land, or in forest-covered land, brush-covered land, or grass-covered land. The guide states that these organizations should maintain the following distances of vegetation clearance from power lines:
a) Four feet away from any line operating at 2,400 or more volts, but less than 72,000 volts
b) Six feet away from any line operating at 72,000 or more volts, but less than 110,000 volts
c) Ten feet away from any line operating at 110,000 or more volts
Utilities are able to achieve exemption from these types of CAL FIRE requirements only if they apply solutions approved by the department to reduce wildfire risk. These solutions are listed with their corresponding code exemptions within the field guide.
To obtain a product exception from CAL FIRE, manufacturers must follow strict test procedures demonstrating the ability to operate without generating sparks or arcs that would otherwise occur with traditional devices. Let’s take a look at how this testing process works.
The CAL FIRE procedure for qualifying electrical equipment and devices for exemption is outlined in CCR Title 14, Section 1255. Under this section, the utility or hardware vendor must submit exemption requests to CAL FIRE with the following materials:
The way I see it, this last step is of critical importance, as all electrical tests for determining compliance must be conducted under the direction of a third-party electrical engineer or fire protection professional. All testing details such as current, voltage, and starting and ending times should also be recorded closely and included in the final documentation provided to CAL FIRE.
When performing a CAL FIRE product exemption test, a radius of flammable vegetation is established around the device under simulated environmental conditions. The equipment is then installed according to manufacturer specifications and energized within its ratings.
The device is then operated to ensure it does not cause ignition risk for the surrounding test material. For example, enclosed devices (like reclosers, sectionalizers, autotransformers, non-expulsion devices, etc.) need to demonstrate that no external arcs/sparks or expelled hot particles are generated during normal operation.
Similarly, open-type or fixed devices (such as air switches, open link fuses, connectors, lightning arresters, manual bypass switches and disconnects) need to interrupt line current and short-circuit current within the design range without creating arcs/sparks or hot particles.
Eaton’s ELF-LR fuse is a product that has been granted permanent exemption by CAL FIRE from pole clearance requirements when the fuse is installed according to manufacturer’s specifications. The exemption test was performed at a utility test lab in California with a fire marshal in attendance providing third-party verification.
As shown in the images below, our full range, current-limiting dropout fuse is engineered with a self-contained design that eliminates noise and expulsive showers — unlike traditional expulsion fuses — making it suitable for use in areas where a high fire hazard exists.
We recognize there is not a one-size-fits-all approach to reducing wildfire risk and recommend utilities focus on approaches that prioritize speed, added intelligence and cost-efficiency. Although adding CAL FIRE exempt solutions is a critical step, Eaton is working with utilities in additional ways to strengthen the grid now and into the future.
For instance, advances in products designed to support underground power systems are becoming a more cost-effective option for some applications. Solid dielectric switchgear in particular is enabling utilities to move overhead lines underground in high-risk areas.
Adding intelligent grid automation schemes can also help automatically and remotely isolate and manage impacted service areas following an event. Solutions like feeder automation software work with recloser controls to isolate the impacted areas of the grid and automatically reconfigure the system to reduce the scale of power outages.
Further, utilities around the country (including some of the largest in California) are also using grid planning software for its powerful modeling capabilities and analytics that provide cutting-edge grid intelligence. These platforms, in tandem with high-fidelity monitoring, provide new levels of accuracy and precision for voltage and current — painting a more detailed picture of what’s happening on the grid. By implementing these technologies across the distribution system, utilities can closely monitor threatening environmental conditions and equipment health for analysis and corrective action.
It’s clear that combatting wildfires is a critical concern. Utilities need to be confident that their equipment will operate safely and efficiently over its service life. The CAL FIRE product exemption process provides just that. At Eaton, we’re helping utilities by continually performing testing of our new and existing wildfire hardening solutions in compliance with CAL FIRE.
We’re also continuing to invest in research and development to advance grid modernization. Whether you’re in California and already meeting the CAL FIRE requirements or anywhere else in the world, creating a more fortified electrical system should be a priority. The investment in intelligent digitalized solutions and site-ready fire-hardening technologies will not only help address wildfire risk — but also help better prepare the electrical grid for the demands of tomorrow.
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