Public power utilities across storm-prone areas of the Pacific Rim and Eastern Seaboard are taking a proactive approach to building grid strength and disaster preparedness.
Five of these utilities have collaborated with APPA to provide case studies on how utilities can get ahead of future disasters, mitigating their impact and keeping communities safe.
Insights from Florida’s Keys Energy Services, Guam Power Authority, New Bern Utilities in North Carolina, Lewes Board of Public Works in Delaware and the U.S. Virgin Islands Power Authority were published in the recent Enhancing Resilience: A Grid Hardening Case Study Report on Coastal Public Power Utilities report, a study funded under a cooperative agreement between APPA and the U.S. Department of Energy (Award Number DE-CR0000012).
Each of these APPA members laid out how utilities facing rising temperatures and storm intensity can build grid security amidst these challenges, addressing them in ways that instate a forward-looking, holistic approach to resiliency.
Studies in Resilience
Communities throughout low-lying coastal areas face some of the most immediate disruptions from climate-exacerbated natural disasters. Rising sea levels and increasingly severe storm activity produce greater risk of flooding and water damage, and the accompanying hurricanes can topple power lines and other critical infrastructure.
This introduces the kind of resilience challenge that can have a totalizing impact on grid security. While prolonged heatwaves put stress on grids during summer months, island communities like Guam, the Florida Keys and U.S. Virgin Islands can face wholesale grid shutdown when inadequate preparedness runs headfirst into a category four hurricane.
APPA’s 2025 resiliency study examined how these five member utilities are working to prevent this outcome and offered a range of solutions for utilities addressing similar challenges.
These utilities found that a combination of reinforcing existing infrastructure and using new technologies to upgrade their grids and monitoring systems was impactful for building resiliency.
As a universal recommendation, replacing utility poles with sturdier construction has proven effective in keeping them stable amidst hurricanes, and relocating transformers or placing them on elevation protected them from flood damage. Bolstering reliability – particularly among communities with only a single connection line to their generation source – served as another foundation of disaster preparedness. These member utilities have addressed this through a combination of keeping a redundant generation source, building out battery storage, and developing microgrids.
These utilities have also explored the possibility of implementing SCADA systems and other smart grid technologies that enhance real-time monitoring, allowing them to more quickly identify and address system disruptions. When calibrated around a given utility’s resources, existing capacities, and the local topography, this approach to coastal resiliency allows public power utilities to get ahead of future disasters, minimizing service disruptions and keeping their customers safe.
While the report’s findings are applicable to any utility looking to build resilience against water and storm stressors, each participant developed their own strategy for advancing safety and minimizing downtime from future incidents.
Guam and the U.S. Virgin Islands
Guam and the U.S. Virgin Islands rest along archipelagos in storm-prone regions, a combination that has put them under pronounced weather stressors.
The U.S. Virgin Islands were struck by two high-intensity hurricanes during the 2017 storm season – hurricanes Irma and Maria – within the span of two weeks. While a harrowing incident for the area’s residents, the damage caused gave the utility a live demonstration of its risk points.
The Virgin Islands Water and Power Authority (WAPA) has developed a resilience plan designed to bear these kinds of long-duration, high-stress weather events. This has entailed a combination of renewable microgrid development, undergrounding of power lines and reinforcement of those remaining aboveground, and hardening of its communications infrastructure to ensure dispatches can be maintained even amidst overwhelming wind and rain. As a result, WAPA was able to keep its generation online during Tropical Storm Ernesto in 2024 due to mitigation activities overseen in the wake of 2017.
Guam sits at the southernmost reaches of the Mariana Islands chain and faces the risk of not only tropical storms and heavy rainfall, but earthquake-induced tsunamis from nearby Japan.
Typhoon Mawar in 2023 was the most devastating storm Guam had faced in twenty years, stressing local infrastructure in ways that allowed the Guam Power Authority (GPA) to identify resilience priorities. This has resulted in a combination of power line undergrounding alongside measures designed to ensure key services continue running even amidst rainfall and heatwaves, such as maintaining energy storage batteries for well water systems, hardening communications, and moving substations indoors and away from the coastline.
New Bern, N.C.
New Bern is facing coastal storm activity as well as the risk that wildfires could spill from the nearby Croatan National Forest.
The region’s formative storm event was Hurricane Florence in 2018, which produced a 10-foot water surge that left $100 million damage to residential and commercial property.
The study noted that New Bern Utilities is focused on assessing system capacity, keeping reserves available to ensure redundancy of operating systems, and establishing the infrastructure necessary to support emergency operations.
New Bern Utilities intends to seek DOE funding for a new 50 MVA substation, retirement of three 50 MVA transformers, extending distribution lines to reroute power to distressed area, undergrounding and right sizing exiting distribution lines to ensure rerouting powering, daily peak and reliability through design, repairs, and to conduct predictive testing.
Pending funding approval, New Bern Utilities has made the following considerations should they receive funding.
The City of New Bern developed a multi-phase, long-term Resiliency and Hazard Mitigation Plan in 2022 that includes utility inputs, provides an overview of New Bern's hydrologic conditions that influence stormwater runoff, and details strategies and recommendations for mitigating impacts.
In alignment with the city’s mitigation plan, New Bern Utilities is seeking additional funding to meet current and future capacity requirements, rerouting power to distressed areas, operations and control center to modernization to include operator workstations, training and testing workstations, as well as upgrades that meet the accessibility requirements of the Americans with Disabilities Act.
Additionally, New Bern Utilities leads a community engagement and outreach effort to inform customers of a Power Cost Adjustment Charge to offset the rising cost of fuel.
The study noted that New Bern Utilities’ hardening techniques have been focused on system maintenance and responding to line extensions for ongoing large scale residential developments which rank their overall duration and length for implementing projects high on the resilience spectrum along with the total dollar value spent or invested to date.
The complexity and intricacy of some of its projects, such as undergrounding and incorporation into a city-wide mitigation strategy, are also considered high on the implementation spectrum.
“The focus and implementation of hardening measures in response to more extreme weather issues and distributed energy resources remain limited and rank low on this reference spectrum, given the demand to meet other hardening project priorities,” the study said.
Lewes, Delaware
During the past few years, Lewes BPW conducted two planned outages to improve grid interconnectedness with Delmarva Power and Light.
The outages resulted in disruption to the entire single line system, lasting more than four hours in duration for consecutive days. With the lack of a redundant line, the risk of an unplanned outage remains high.
Additionally, the City of Lewes is predominately a retirement community comprised of part-time residents who support undergrounding utilities for aesthetic purposes, but whose buy-in is often influenced by convenience and overall cost, the study noted.
Lewes BPW is in the initial scoping phase with multiple attempts applying for FEMA Hazard Mitigation Grant Program funds to support several hardening projects that include:
- The undergrounding of lines in areas that are not deemed historical or have tribal artifacts;
- Repositioning 16 pump stations;
- Upgrading transformers and pads near coastal areas to noncorrosive materials;
- Replacing wood poles for steel; and
- Relocating the wastewater treatment plant from a flood plain.
Due to the number of part-time residents, Lewes BPW maintains a Readiness to Serve Charge and a Commodity Charge based upon consumption to cover the cost of infrastructure maintenance.
Lewes BPW previously had a Mitigation Committee, which was sunsetted, but proactively benchmarked many of these projects based on limiting risk and reducing costs.
A resolution was passed that requires new or rehabilitated construction projects to include underground lines.
Lewes BPW’s strategic planning is sustained through annual reviews. Priorities include building redundancy and reliability in critical service areas (e.g., hospitals) and automating the grid.
Lewes BPW’s unique customer base influences the implementation of its hardening projects and, therefore, ranks high on the resilience spectrum along with the duration or time it takes to implement complex and intricate projects, such as undergrounding.
In contrast, the total dollar value that has been awarded or invested is considered relatively low, to date, until the time when projects commence and spending increases.
“Additionally, the focus and implementation of hardening measures in response to more extreme weather issues and DER remain limited for the BPW and is therefore identified as low on this reference spectrum.”
Keys Energy Services
In an interview with APPA, Keys Energy Services (KEYS) CEO and member of APPA’s Board of Directors Lynne Tejeda discussed the utility’s work building resiliency in ways that address the region’s specific geography and weather risks.
The Florida Keys rests at the point where currents from the Gulf of Mexico move outwards towards the Atlantic. This places the region at the center of a major storm front, one that results in seasonal hurricanes that tend to strike the Florida Keys with particular intensity.
The communities’ position as a storm landing point resulted in two notable hurricanes striking the region – Hurricane Wilma in 2005 and Hurricane Irma in 2017 - that acted as a live test for KEYS’ disaster preparedness. Both were category five hurricanes at their peak, and represent a pattern of Gulf Stream cyclones becoming increasingly frequent and damaging.
“We've had some pretty good scares, and we've also had some pretty good landfalls over the years. So obviously hurricanes are our number one concern, something that we plan quite thoroughly for,” Tejeda said.
Tejeda noted that hurricanes Wilma and Irma stressed different parts of grid infrastructure and provided lessons on how to best prepare for future incidents.
While Wilma’s winds were less destructive than similar events, it produced a level of flooding that was instructive for how KEYS can protect its infrastructure from water surges.
“The Florida Keys had not seen that level of flooding before Wilma... What it meant for us was it really reinforced the need to make sure our distribution transformers were elevated.
After that it became a firm policy to put them on concrete pads. We also decided to make sure that people installed their meter centers at a greater height,” Tejeda said.
By contrast, Hurricane Irma produced unusually strong winds that stressed KEYS power lines, causing widespread damage to transmission and distribution infrastructure . In the aftermath, the utility decided to install stronger poles and engage in more frequent inspections to ensure their stability.
“We were well on our way to storm hardening along eight-year inspection cycles where we looked at our poles to determine whether they needed to be replaced. And we decided to do that on four-year cycles rather than eight-year cycles,” Tejeda said.
This has led to a policy of using ductile iron poles in place of wood, since ductile iron showed total resilience in Irma’s wake.
“We made the decision that instead of restoring poles identified as weak, we were going to replace all our old wood poles with ductile iron poles. While we lost almost 700 distribution and transmission poles during Hurricane Irma, we saw that the none of the poles that we had already replaced with ductile iron failed. So, we accelerated our pole replacement policy,” Tejeda said.
Installing ductile iron poles has proven effective for building transmission resilience since, as Tejeda noted, the Florida Keys’ archipelago geography makes undergrounding power lines difficult if not impossible.
Staying Above Water
The combination of rising sea levels and more intense storm surges means that water encroachment – even from relatively mild storms – has become one of KEYS’ top resilience concerns.
The utility has worked to place its transmission infrastructure and critical buildings on higher elevation to prevent floods from either damaging them or rendering them wholly inoperative during future storms.
“We put in a new transmission and distribution building for lineman and electricians that is an elevated structure. We also redid our primary service building, which has our control Center and it's elevated. It's not quite above the floodplain, so we installed flood panels that can be deployed to prevent water from intruding,” Tejeda said.
As has been the case with KEYS’ broader approach to resilience development, Tejeda noted this has involved using lessons from past incidents to ensure stress and damage from future disasters are mitigated.
“Elevation is important. The control buildings in our substations are all elevated and the pad-mount distribution transformers are elevated as well. The primary thing when it comes to water is to plan ahead and have as many facilities as possible elevated. That was our primary goal in the wake of Hurricane Wilma,” Tejeda said.
Community Safety
In addition to securing grid infrastructure, KEYS has taken efforts to keep their staff and customers safe amidst future hurricanes.
The relative lack of land throughout the Florida Keys, as well as the community’s closeness to water, means the utility has needed to ensure its own facilities are hardened against the same water surges and high-powered winds it is endeavoring to protect its transmission infrastructure from.
Hardening its own facilities against storm damage has also made it easier for KEYS staff to respond and rebuild in the wake of future hurricanes.
“After Irma we had significant damage to our warehouses, and we struggled through the recovery with challenges in distributing our inventory and materials. That really highlighted the need to pay attention to our own facilities,” Tejeda said.
This has included an ongoing dedication to keeping utility personnel safe so they can subsequently aid the community once the storm has passed.
“We can't serve our community if we don't have facilities that are in good shape. So we now have three Category 5 buildings - meaning they're rated to the highest strength and have become good safe havens for our employees to weather the storm,” Tejeda said.
Another aspect of community safety KEYS has worked on reinforcing is the reliability of its communications channels, whose susceptibility to storm outages would otherwise be a liability when coordinating response and keeping customers informed in the wake of natural disasters.
One of the immediate solutions was to coordinate with telecom companies in setting up local hotspots.
“There's been a couple storms where we have been without internet and telephone connection for days afterward. Some of the big companies have agreed to bring hotspots down to us that we would get within a couple of days,” Tejeda said.
Additionally, KEYS has contracted with Starlink to provide satellite internet that Tejeda noted would be critical for facilitating repair and mutual aid efforts.
“We also have our own Starlink. We made sure to get one large enough to carry our Internet load and our critical communications. So, if we do lose our connectivity again, we’ll retain the ability to reach out and seek help from our mutual aid network and others,” Tejeda said.
