

UI’s Storm Resiliency Plan, which was submitted recently to the Connecticut Public Utilities Regulatory Agency, details four projects that would protect vulnerable grid components from flood- and storm-related damage, and facilitate restoration of outages. The projects would complement measures UI has already initiated, and plans to initiate, to increase the resiliency of its electric grid and protect it from storms.

“At UI, we’re proud of our strong record of providing safe and reliable service to our customers, but we also know that some parts of our grid could still be vulnerable to extreme weather and flooding,” said Joseph D. Thomas, UI’s vice president for Electric System Operations. “This plan identifies several projects we can undertake over the next four years to shore up those vulnerabilities and significantly reduce the likelihood thousands of customers will experience prolonged outages.”

The Storm Resiliency Plan arose from a series of commitments UI’s corporate parent made in a settlement agreement with the state of Connecticut, which paved the way for approval of the merger last year of UIL Holdings Corporation and Iberdrola USA. AVANGRID, Inc. is the new name of the merged organization.

In keeping with that settlement agreement, if the plan is approved UI would be authorized to spend $50 million on distribution resiliency through 2020 to protect its grid from storms. UI would then be able to seek to recover the cost of the projects through customer rates, but it would absorb certain financing costs, resulting in a net benefit to customers of about $5 million.

The additional resiliency projects include:

  • Pequonnock Substation Relocation: This Bridgeport substation, which serves approximately 8,000 customers, has been identified as at significant risk for damage from coastal flooding during storms. This project would coordinate with the relocation of the transmission portion of the substation by relocating the substation’s distribution components to higher ground, reducing the risk of a potentially catastrophic failure that could leave thousands of customers without power for prolonged periods. Distribution Project cost: $31 million

  • Perimeter Feeder Ties: UI’s electric grid is designed for redundancy, so that parts of one circuit can be switched to another circuit when there’s a line down or similar outage-causing event. This project will create nine additional circuit ties between remote areas of the grid, allowing for a faster restoration of customers in areas where an effective back-up is not readily available. Project cost: $7.6 million

  • Step-Down Bank Removal: Most of UI’s electric distribution grid operates on a standard 13.8-kilovolt voltage. But there are pockets that still operate on lower voltages. This project would accelerate an existing initiative to upgrade lower-voltage lines, transformers and related equipment in 13 of these pockets, and remove the “step-down banks” that link them with the surrounding higher-voltage grid. This will provide additional back-up opportunities for operational flexibility, and eliminate potential single points of failure during weather-related events. Project cost: $6.3 million

  • Substation Getaway Rebuild: This project would separate and bury underground “feeder” cables as they emerge from substations at 3 locations in UI’s service territory, reducing the likelihood that major weather or other event could cause multiple feeders to fail. Each identified location serves up to 3,100 customers.Project cost: $5 million

After Tropical Storm Irene in 2011 and Super Storm Sandy in 2012, UI initiated a series of programs to protect customers from storm-related outages and reduce the time it takes to restore power when it is lost.

It invested $15 million to provide short-term protection of coastal substations against flooding and began implementing a new, state-approved program to create a wider buffer between overhead lines and encroaching vegetation. It is also adopting new systems to automate storm-response operations, providing restoration planners a more detailed picture of damage so they can deploy crews and resources more efficiently, provide more information to customers, and restore service more quickly.