Utility-caused wildfires

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Camp Fire, as seen by the Landsat 8 satellite on November 8, 2018. Red highlights active fire seen in infrared. Camp Fire oli 2018312 Landsat.jpg
Camp Fire, as seen by the Landsat 8 satellite on November 8, 2018. Red highlights active fire seen in infrared.

Utility-caused wildfires are a subsection of human-caused wildfires that are directly ignited by utilities, usually power lines. They are unplanned ignitions that can cause wild burns. [1] Hotter and drier weather as a result of climate change has been liked to lower moisture content in vegetation, which, along with high tree mortality has created ideal wildfire conditions. [2] Ignition often occurs when power lines come in contact with vegetation, whether elevated or on the ground. [1]

Contents

Industry critics claim that the industry is not doing enough to mitigate these disasters. [3]

Examples

Throughout the world, utilities, especially overhead power lines, have caused wildfires. [4] In 2023, downed power lines sparked fires in Lahaina, Hawaii. [5] In February 2024, on the Texas Panhandle, a decayed utility pole fell on dry grass and sparked the largest wildfire in state history. [6] The 2018 Camp Fire, the deadliest and most destructive wildfire in California state history, was caused by a single faulty hook on a PG&E transmission line. [7] [8] In the notorious 2009 'Black Saturday' fires in Victoria, Australia fires sparked by power lines killed 159 people and caused more than $4 billion (AUS) dollars in damages. [9] In Greece, on August 11th, a wooden electricity pillar with a loose cable held with a clothes hanger, sparked a fire that killed one woman and burned over 10,000 hectares. [10]

Causes

Utility-cased wildfires can be started by a variety of factors.

Downed lines

The vast majority of transmission lines, over 70%, in the United States are outdated, and are near 25 years old. [11] The average age for power transformers that power over 90% of the country is 40 years old. [12] Power lines, whether old or new, are susceptible to storm damage, and, in 30% of cases, the power line does not automatically shut off. [13] This can happen when the fallen line draws too little electric current to activate a fuse or circuit breaker. [13] These high-impedance faults (HiZ) can cause high-energy, high-temperature arcing that can cause ignition. [13]

Contact with vegetation and foreign objects

Vegetation contact, and contact with foreign objects, such as trees, are leading causes of wildfires. [1] In California, these factors were responsible for 35%, and 18%, respectively, of utility-related fires larger than 10 acres. [1] Strong winds have been known to exacerbate these problems. [1] Live wires can ignite dry vegetation and fuels, and fallen trees can result in downed lines. [13]

Conductor slap

Power lines are traditionally designed with significant clearance between conductors, this prevents them from contacting under normal operating conditions. [14] Under poor conditions, line conductors can slap against one another; this causes high energy arcing, and, occasionally, small bits of molten metal (generally aluminum) are ejected. [15] These ejected pieces of molten aluminum can ignite wildfires. [13]

Component failure

Many components, such as switches, transformers and insulators, contain thousands of complex circuits and parts. [16] While often able to effectively provide service for decades, they do eventually fail. [13] Occasionally, before complete failures, there is electric arcing and sparks that are too small to be detected by fail-safe sensors. [13] These sparks and electric arcs can result in the ignition of vegetation or foreign objects. [13]

Solutions

Electric companies are investigating solutions such as burying power lines, installing sensors, and using software to monitor cables and automatically shut them off. [3] In 2023 wildfire mitigation plans, Californian utility companies proposed over $9 billion to mitigate factors that cause wildfires. [17]

Related Research Articles

<span class="mw-page-title-main">Insulator (electricity)</span> Material that does not conduct an electric current

An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials—semiconductors and conductors—conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are non-metals.

<span class="mw-page-title-main">Electric power transmission</span> Bulk movement of electrical energy

Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a transmission network. This is distinct from the local wiring between high-voltage substations and customers, which is typically referred to as electric power distribution. The combined transmission and distribution network is part of electricity delivery, known as the electrical grid.

<span class="mw-page-title-main">Static electricity</span> Imbalance of electric charges within or on the surface of a material

Static electricity is an imbalance of electric charges within or on the surface of a material. The charge remains until it can move away by an electric current or electrical discharge. The word "static" is used to differentiate it from current electricity, where an electric charge flows through an electrical conductor.

<span class="mw-page-title-main">Electric power distribution</span> Final stage of electricity delivery to individual consumers in a power grid

Electric power distribution is the final stage in the delivery of electricity. Electricity is carried from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between 2 kV and 33 kV with the use of transformers. Primary distribution lines carry this medium voltage power to distribution transformers located near the customer's premises. Distribution transformers again lower the voltage to the utilization voltage used by lighting, industrial equipment and household appliances. Often several customers are supplied from one transformer through secondary distribution lines. Commercial and residential customers are connected to the secondary distribution lines through service drops. Customers demanding a much larger amount of power may be connected directly to the primary distribution level or the subtransmission level.

<span class="mw-page-title-main">Spark gap</span> Two conducting electrodes separated in order to allow an electric spark to pass between

A spark gap consists of an arrangement of two conducting electrodes separated by a gap usually filled with a gas such as air, designed to allow an electric spark to pass between the conductors. When the potential difference between the conductors exceeds the breakdown voltage of the gas within the gap, a spark forms, ionizing the gas and drastically reducing its electrical resistance. An electric current then flows until the path of ionized gas is broken or the current reduces below a minimum value called the "holding current". This usually happens when the voltage drops, but in some cases occurs when the heated gas rises, stretching out and then breaking the filament of ionized gas. Usually, the action of ionizing the gas is violent and disruptive, often leading to sound, light, and heat.

<span class="mw-page-title-main">Substation</span> Part of an electrical transmission, and distribution system

A substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions. Between the generating station and consumer, electric power may flow through several substations at different voltage levels. A substation may include transformers to change voltage levels between high transmission voltages and lower distribution voltages, or at the interconnection of two different transmission voltages. They are a common component of the infrastructure. There are 55,000 substations in the United States.

<span class="mw-page-title-main">Single-wire earth return</span> Supply energy using single wire with earth as return

Single-wire earth return (SWER) or single-wire ground return is a single-wire transmission line which supplies single-phase electric power from an electrical grid to remote areas at lowest cost. The earth is used as the return path for the current, to avoid the need for a second wire to act as a return path.

<span class="mw-page-title-main">Pacific Gas and Electric Company</span> American utility company

The Pacific Gas and Electric Company (PG&E) is an American investor-owned utility (IOU). The company is headquartered at 300 Lakeside Drive, in Oakland, California. PG&E provides natural gas and electricity to 5.2 million households in the northern two-thirds of California, from Bakersfield and northern Santa Barbara County, almost to the Oregon and Nevada state lines.

<span class="mw-page-title-main">High voltage</span> Electrical potential that is large enough to cause damage or injury

High voltage electricity refers to electrical potential large enough to cause injury or damage. In certain industries, high voltage refers to voltage above a certain threshold. Equipment and conductors that carry high voltage warrant special safety requirements and procedures.

<span class="mw-page-title-main">Electric arc</span> Electrical breakdown of a gas that results in an ongoing electrical discharge

An electric arc is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma, which may produce visible light. An arc discharge is initiated either by thermionic emission or by field emission. After initiation, the arc relies on thermionic emission of electrons from the electrodes supporting the arc. An arc discharge is characterized by a lower voltage than a glow discharge. An archaic term is voltaic arc, as used in the phrase "voltaic arc lamp".

<span class="mw-page-title-main">Recloser</span> Electricity distribution networks circuit breakers

In electric power distribution, automatic circuit reclosers (ACRs) are a class of switchgear designed for use on overhead electricity distribution networks to detect and interrupt transient faults. Also known as reclosers or autoreclosers, ACRs are essentially rated circuit breakers with integrated current and voltage sensors and a protection relay, optimized for use as a protection asset. Commercial ACRs are governed by the IEC 62271-111/IEEE Std C37.60 and IEC 62271-200 standards. The three major classes of operating maximum voltage are 15.5 kV, 27 kV and 38 kV.

<span class="mw-page-title-main">Arc flash</span> Heat and light produced during an electrical arc fault

An arc flash is the light and heat produced as part of an arc fault, a type of electrical explosion or discharge that results from a connection through air to ground or another voltage phase in an electrical system.

In an electric power system, a fault or fault current is any abnormal electric current. For example, a short circuit is a fault in which a live wire touches a neutral or ground wire. An open-circuit fault occurs if a circuit is interrupted by a failure of a current-carrying wire or a blown fuse or circuit breaker. In three-phase systems, a fault may involve one or more phases and ground, or may occur only between phases. In a "ground fault" or "earth fault", current flows into the earth. The prospective short-circuit current of a predictable fault can be calculated for most situations. In power systems, protective devices can detect fault conditions and operate circuit breakers and other devices to limit the loss of service due to a failure.

<span class="mw-page-title-main">Underground power line</span> Replacement of above-ground power and telecommunications cables with underground ones

An underground power line provides electrical power with underground cables. Compared to overhead power lines, underground lines have lower risk of starting a wildfire and reduce the risk of the electrical supply being interrupted by outages during high winds, thunderstorms or heavy snow or ice storms. An added benefit of undergrounding is the aesthetic quality of the landscape without the powerlines. Undergrounding can increase the capital cost of electric power transmission and distribution but may decrease operating costs over the lifetime of the cables.

<span class="mw-page-title-main">AusNet Services</span> Australian energy company

AusNet Services is an Australian energy delivery services business, owning and operating more than $13 billion of electricity and gas network assets. It is privately held, and was formerly listed on the Australian Securities Exchange (ASX) and the Singapore Exchange (SGX). AusNet is currently owned by Australian Energy Holdings No 4 Pty Limited, a company controlled by Brookfield Asset Management. The co-investors include pension funds in Australia and Canada.

<span class="mw-page-title-main">Aerial bundled cable</span>

Aerial bundled cables are overhead power lines using several insulated phase conductors bundled tightly together, usually with a bare neutral conductor. This contrasts with the traditional practice of using uninsulated conductors separated by air gaps. This variation of bundled conductors utilizes the same principles as overhead power lines, except that they are closer together to the point of touching but each conductor is surrounded by an insulating layer.

<span class="mw-page-title-main">Conductor clashing</span> Electrical issue from unintended contact

In an overhead power line, conductor clashing occurs when energized wires accidentally come into contact with each other. Overhead transmission systems typically use un-insulated bare conductors for reasons of weight and economy. When bare conductors touch, the resulting momentary short circuit or electric arc can cause disturbances to the electric power system, damage to the conductors, or fire. Conductor clashing may be caused by wind, ice, excess sag due to creep or thermal expansion due to sustained heavy loading, or by contact with animals or objects. Conductor clash is prevented by proper design and installation to anticipate the likely conditions of weather and load. The effects of clashing conductors can be mitigated by fuses or protective relays and circuit breakers to de-energize the shorted conductors. For some types of transmission line, it may be possible to automatically reclose a circuit breaker in expectation that the clash was a momentary problem, thus minimizing interruption of service to grid customers.

<span class="mw-page-title-main">Trembler coil</span> Part of early car ignition systems

A trembler coil, buzz coil or vibrator coil is a type of high-voltage ignition coil used in the ignition system of early automobiles, most notably the Benz Patent-Motorwagen and the Ford Model T. Its distinguishing feature is a vibrating magnetically-activated contact called a trembler or interrupter, which breaks the primary current, generating multiple sparks during each cylinder's power stroke. Trembler coils were first used on the 1886 Benz automobile, and were used on the Model T until 1927.

The 2019 California power shutoffs, known as public safety power shutoff (PSPS) events, were massive preemptive power shutoffs that occurred in approximately 30 counties in Northern California and several areas in Southern California from October 9 to November 1, 2019, and on November 20, 2019, by Pacific Gas and Electric Company (PG&E), Southern California Edison (SCE), and San Diego Gas & Electric (SDG&E).

<span class="mw-page-title-main">Bobcat Fire</span> 2020 wildfire in Southern California

The Bobcat Fire was a large wildfire in Los Angeles County during the 2020 California wildfire season. The fire ignited on September 6, 2020, and burned 115,997 acres (46,942 ha) before it was fully contained by November 27. The Bobcat Fire primarily burned in the central San Gabriel Mountains, in and around the Angeles National Forest, and is one of the largest fires on record in Los Angeles County to date.

References

  1. 1 2 3 4 5 "REDUCING UTILITY-RELATED WILDFIRE RISK" (PDF). energysafety.ca.gov. Public Utilities Commission and Boston Consulting Group. December 2020. Archived from the original (PDF) on 2022-02-24. Retrieved 18 October 2024.
  2. ↑ Park Williams, A.; Allen, Craig D.; Macalady, Alison K.; Griffin, Daniel; Woodhouse, Connie A.; Meko, David M.; Swetnam, Thomas W.; Rauscher, Sara A.; Seager, Richard; Grissino-Mayer, Henri D.; Dean, Jeffrey S.; Cook, Edward R.; Gangodagamage, Chandana; Cai, Michael; McDowell, Nate G. (March 2023). "Temperature as a potent driver of regional forest drought stress and tree mortality". Nature Climate Change. 3 (3): 292–297. doi:10.1038/nclimate1693. ISSN   1758-6798.
  3. 1 2 Penn, Ivan (22 March 2024). "Utility-Caused Wildfires Are Becoming a National Problem". The New York Times.
  4. ↑ Boxall, Bettina (5 January 2020). "Human-caused ignitions spark California's worst wildfires but get little state focus". San Diego Union-Tribune. Archived from the original on 19 June 2023.
  5. ↑ "Deadly Maui wildfire was sparked by downed power lines, investigation finds". Yahoo News. 2024-10-03. Retrieved 2024-10-06.
  6. ↑ "Decayed power pole sparked the largest wildfire in state history, Texas House committee confirms". Marfa Public Radio, radio for a wide range. 2024-05-02. Retrieved 2024-10-06.
  7. ↑ Zimmerman, Jeffrey. November 2018 Camp Fire. National Oceanic and Atmospheric Administration, Jan. 2020, https://www.weather.gov/media/publications/assessments/sa1162SignedReport.pdf.
  8. ↑ Derbeken • •, Jaxon Van (2019-12-06). "New Images of PG&E Hooks on Camp Fire Power Line Released". NBC Bay Area. Retrieved 2024-10-06.
  9. ↑ "How an Australian State Fought Back Against Grid-Sparked Wildfires - IEEE Spectrum". spectrum.ieee.org. Retrieved 2024-10-06.
  10. ↑ Souliotis, Yannis; Maltezou, Renee (15 August 2024). "Faulty power cable may have caused Greece's worst wildfire this year, sources say".
  11. ↑ U.S. Department of Energy. Quadrennial Energy Review Energy Transmission, Storage, and Distribution Infrastructure. 2015.
  12. ↑ Tompkins, Al (2022-12-27). "When will we update our power grid?". Poynter. Retrieved 2024-10-03.
  13. 1 2 3 4 5 6 7 8 "How Do Power Lines Cause Wildfires?". Texas Wildfire Mitigation Project. 2014-02-13. Retrieved 2024-10-06.
  14. ↑ "Power Line Safety". International Sign Association. Retrieved 2024-10-07.
  15. ↑ Short, Tom (10 October 2024). "Conductor Slap" (PDF). Electric Power Research Institute.
  16. ↑ "Transformers: Explaining the basics". CALCO. 10 October 2024.
  17. ↑ Warner, Cody; Callaway, Duncan; Fowlie, Meredith (February 2024). "Risk-Cost Tradeoffs in Power Sector Wildfire Prevention" (PDF). Energy Institute at Haas.
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