Hurricane Risk Assessment of Power Distribution Poles Considering Impacts of a Changing Climate

Storm-related power outages cause approximately $270 million per year in repair costs in the United States. As a result of increasing sea surface temperatures caused by the changing climate, hurricane patterns (i.e., intensity/frequency) may change; however, there is much uncertainty as to how climate change may affect hurricane patterns. Implications of the changing hazard patterns on hurricane risk warrants an investigation to evaluate the potential impact of climate change on power distribution pole failure. This paper proposes a probabilistic framework to evaluate the vulnerability of power distribution poles to hurricanes under the potential impact of a changing climate. Two methods for the design of distribution poles in the United States, the National Electric Safety Code method and the ASCE method, are considered to investigate the difference of the vulnerability of a distribution pole subjected to hurricane hazard. The framework includes a reliability analysis of the designed power distribution poles using fragility analysis, the effects of degradation of timber poles, probabilistic wind models, and an assessment of the potential impacts of climate change on the annual failure probability of power distribution poles. This paper finds that climate change may have a significant effect on the structural failure probabilities of distribution poles. The age of the poles has a significant impact on the reliability of power distribution poles, which warrants the exploration of cost-effective methods to determine when a distribution pole should be replaced to ensure adequate strength to withstand wind loads. DOI: 10.1061/(ASCE)IS.1943-555X.0000108. (c) 2013 American Society of Civil Engineers.