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Are Your Wood Poles Protected Against Fires?

May 7, 2024
Electric utilities have options to protect assets from increased fire damage and cost risks.

Wildfires have been increasing in size and damage for the last 30 years, and higher temperatures have led to drier conditions, increased drought and longer fire seasons. According to the National Interagency Fire Center, the number of acres in the U.S. burned by wildfires has more than doubled since 1985: 3.3 million acres (1.3 million hectares) from 1985 to 1999 vs. 7 million acres (2.8 million hectares) from 2000 to 2020.

And the cost to suppress these fires has increased at an even higher rate, with the federal government spending an average of US$1.6 billion per year on wildfire suppression.

A Holistic Approach

Utilities may pursue a range of methods to harden their plants, including undergrounding power lines and replacing wood poles with alternate materials such as steel or concrete. These options can come with a hefty financial and operational cost — especially when they are done ad hoc rather than as part of a comprehensive, coordinated program.

The good news is fire prevention can be a key component of a holistic approach to a utility grid’s resiliency and asset hardening initiatives. Extending the life of existing assets by asset inspection, using data analytics to prioritize hardening needs and applying remedial coatings or wraps to structures that stave off fire damage can be far more cost-effective and less operationally intensive. With thoughtful coordination, when grid asset service teams are already in the field assessing and restoring assets, they also can deploy solutions that reduce the impact of a wildfire on those assets.

Asset Fire Protection

Utilities have multiple ways to protect against fire — before one ever breaks out. Cost-effective remedial applications can be proactively applied to existing wood poles to protect against potential fire damage and extend the life of existing assets. Options can include fire-retardant mesh wraps that expand and protect the pole in high temperatures, as well as spraying or brushing a fire-retardant coating directly on poles.

These fire-hardening methods have proven successful in the field. For example, a large electric utility in the western U.S. chose to proactively coat nearly 1000 poles in its grid system. The poles supported multiple high-value transmission lines in an area identified as elevated risk for brush fires. These assets experienced two consecutive fires in less than 60 days, and only one of the poles required replacement due to damage above the treated area. The utility was able to treat the same poles again — after removing the fire exposed coating — so they can protect against possible future fires. Another example includes a large Canadian utilities whose wise investment to wrap with a fire retardant mesh resulted in zero of the wrapped structures failing, and saved millions of dollars in avoided repair and outage costs.

Utilities also deploy visual assurance patrols to identify damage or defects, such as broken hardware, broken or missing crossarms and other potential hazards as well as right-of-way encroachments. Crews can conduct an infrared thermography inspection, which reveals any areas of overheating on the pole, and an overhead detail inspection for conformity to code.

Additionally, utilities can improve the pole resiliency through upgrading and hardening poles with trusses and conduct a pole loading analysis, using technology to capture actionable data on pole integrity and resiliency.

During a fire, utilities can send resources into the field to treat assets ahead of advancing flames. A southwest U.S. electric cooperative took this remedy when a wildfire broke out. The utility sent crews to apply a latex-based fire protective coating to utility poles in the path of the fire. Crews selected a safe starting point in front of the fire location and applied the protective coating to 1100 poles. As the fire blazed across 27,000 acres (10,927 hectares), the fire took down 220 untreated poles, 60 homes and several other buildings, but the 1100 treated poles survived.

And, after a fire, utilities are encouraged to perform a visual damage assessment to determine the status of poles exposed to the fire, restore candidate poles with trusses, replacing damaged poles as needed, and perform new asset inventory verification that includes cataloging new pole locations and documenting attachments.

Capitalization Of Assets

When a wood pole is damaged and cannot remain in service for its predicted useful life, but rather must be replaced prematurely, it can be very expensive. The cost of a wood pole hardening program that includes treatment is substantially less than replacing many lost poles sooner than necessary. The outlined fire protective solutions result in longer asset lives and improved performance of both the assets and the overall system. Therefore, they should be capitalized and depreciated, especially if wildfire is a risk factor in the area. Note that the cost of wildfire protective products can be recorded in Federal Energy Regulatory Commission (FERC) Account 364, which includes the cost of poles, towers and fixtures.

A comprehensive inspection and treatment program that clearly identifies poles with a substantial amount of expected useful life remaining can make an even better case for capitalizing and depreciating the cost of wildfire protective products and services.

A Best Practice

When poles survive a wildfire, power to customers is more likely to remain in service without interruption. In areas where wildfires occur — a growing area each year — taking a complete-solution approach to grid asset fire protection should be a best practice for utilities. Hardening a structural grid asset is smarter than replacing it, whenever possible. Protecting it from damage in the first place is even smarter.

Solutions for asset fire protection can be applied, at speed and scale, as part of an existing or new grid asset inspection or restoration program. Taking such a holistic approach to the grid system, including protection against wildfire damage, is the kind of efficient, effective and sensible decision rate payers expect from their utilities.

Chad Newton is the Senior Portfolio Director – Wood Infrastructure at Osmose. He holds a BS in Mechanical Engineering and a MBA, both from the Georgia Institute of Technology. He is active in the IEEE PES Overhead Lines Subcommittee, a member of ASC O5, and a member of AWPA. In his current role, he oversees the design, development, and implementation of Osmose’s industry leading wood pole inspection, protection, and restoration products and services as well as Osmose’s Structural Resiliency as a Service. He and his team focus on bringing valuable innovation in the areas of evaluation, life extension, protection, and strengthening of wood poles to enable a more structurally resilient grid.

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