Hurricane Grid Hardening

A significant development in Grand Bahama required a new 22 mile [35.4 km] 69kV line to be built. With frequent hurricane exposure, the project needed to push the limits of accepted overhead line storm resilience to reliably deliver service to the west end of the island.  

The island location presented many project challenges. In addition to hurricanes, the salt spray corrosion issues and soil pH levels which would limit steel pole service life and the island location logistical challenges which would result in costly material handling issues with concrete poles. Of all the engineered pole material options available, PowerON composite poles were chosen over steel and concrete poles. The lightweight, inert poles are comprised of sections that nest together, ensuring that the 65 ft. [19.8m] poles can fit into standard sized 40 ft. intermodal shipping containers. Furthermore, PowerON poles have an 80-year service, requires no scheduled maintenance, and are covered by a 41-year warranty

Designed in 2008 by Barkey Technologies, the maximum windspeed requirement of 150 mph [67.1 m/s], which was used in the NESC Rule 250C design criteria, was chosen due to the extreme winds of 120 mph [53.6 m/s] that were observed in recent hurricanes up until that time. Engineered using Power Line Systems’ PLS-POLE™ software, construction on the all-composite line, which included 3M ACCR conductor, Ohio Brass polymer insulators and CentraCore OPGW, was started in 2009.  

In 2016, Grand Bahama was hit by Hurricane Matthew, a Category 4 storm with winds of 140 mph [62.6 m/s]. The island’s west end took a direct hit and about 10% of the island’s poles were downed, over 2,300 wood poles. As the restoration efforts continued and the crews travelled out to the far ends of the island to assess the damage, there was one observation that became clearer and more unbelievable with each passing span: The PowerON composite poles had stood strong during the hurricane.  

On September 1st, 2019, another, now notorious, hurricane hit the island, Category 5 Dorian, packing wind gusts to 220 mph [98.3 m/s]. Dorian’s slow pace of 25 miles [40 km] in 24 hours resulted in damage of $7 billion and set a record for the slowest-moving Category 5 Atlantic hurricane ever. Again, 1,000's of wood pole were lost. A text message received from Grand Bahama Power Vice President, Frank Woodworth, on September 4th confirmed that the PowerON composite poles had survived… again, including the newest PowerON installation in Freeport. 

PowerON composite poles mitigate the threat of hurricane damage and speed restoration efforts because the poles stand strong.