Disaster Response: How Power Generators Prepare to Weather the Storm

Natural disasters can strike anywhere, and the events of recent years—hurricanes, flooding rains, bomb cyclones—have ramped up the efforts of utilities to prepare for extreme weather. Power companies are utilizing technology to develop new protocols and evolve their best practices in an effort to more swiftly and safely restore power to affected areas.

High winds, ice storms, and lightning strikes; heavy rains and flooding; spring snowstorms breaking limbs and toppling trees; wildfires; and hurricanes and tropical storms—these threats are all too familiar. Utilities must prepare for, and be ready to respond to, all manner of extreme weather.

Events of the past year—everything from bitter cold, to scorching heat, to the impacts of multiple hurricanes on the U.S. and the Caribbean—highlight the need for reliability and resiliency in the power grid. Areas were without power for a few hours, to a few days, to weeks, and in some cases—such as in Puerto Rico—months.

Lessons have been learned. New technologies have been developed and deployed. Reliability and resiliency have become buzzwords. Weather and power generation experts who spoke with POWER agree that improvements are being made in the areas of rebuilding and restoration after a storm, and there’s a renewed focus on preparations and best practices both before and after disaster strikes.

“Natural disasters hit nearly every continent in 2017. We have seen flooding and monsoons in Southeast Asia, landslides in Africa, earthquakes in Mexico and Central America, and a barrage of hurricanes that destroyed many Caribbean islands and impacted the south and east coasts of the United States,” Raul Pereda, president and CEO of PW Power Systems, now part of Mitsubishi Hitachi Power Systems, told POWER. “Millions of homes were destroyed, schools were closed, water treatment facilities faltered, and hospitals were shut down. To restore critical infrastructure, reliable power is a must. One underestimated area of destruction that presents a major barrier to recovery is [a] widespread power outage. Power reliability is a basic need for disaster-affected communities, right alongside medical care, water, and food. Governments and municipal authorities can put proactive plans in place to ensure power infrastructure is restored with minimal down time so that citizens are not left in the dark.”

Being Proactive Is Part of the Protocol

Getting the lights back on is job one for utilities in the aftermath of destructive weather events. That also means being proactive prior to a storm and having action plans in place to deal with the damage. Best practices and protocols must account for many variables, including the safety of personnel moving into impacted areas.

“First, you need to know the weather risks, and how those risks vary across your network on a location-by-location basis,” Jon Porter, vice president and general manager of AccuWeather Enterprise Solutions, told POWER. “When you clearly understand the potential risks of different weather events, you’re in a better position to proactively manage those risks. Second, to keep your people safe and your operations as resilient as possible, you need weather insights that enable you to make decisions before severe weather hits. Getting early, advance notice of extreme events in your region is critical for creating an initial plan. As the event nears and more localized and accurate insights are available, you can adjust that plan. You need to position crews in the right place at the right time so that they can have the maximum impact on reducing restoration time for your customers. You may need to plan for mutual aid crews, secure hotels for those crews, identify staging areas, and more, in advance. To do that with maximum efficiency and safety, you need the best weather information you can get.”

Staging operations (Figure 1) were in evidence prior to last year’s hurricanes that struck the Caribbean as well as Texas, Florida, and other areas on the U.S. mainland. Utilities sent crews and equipment to locations near the storms’ paths so they could quickly mobilize once the danger passed.

Figure 1 - Barge to PR 1
1. Ready for deployment. Xcel Energy was among the nearly 60 investor-owned electric companies and public power utilities that sent personnel to Puerto Rico in the aftermath of Hurricane Maria, which struck in September 2017 and destroyed much of the island’s aging power distribution system. Xcel trucks and equipment are seen here on a barge in Lake Charles, Louisiana, where they were staged prior to heading to Puerto Rico. Courtesy: Xcel Energy

“You need to assess the damage to set priorities, and weather insights can help determine what areas might have been most affected,” Porter said. “Then you want to return your crews to operation as quickly as possible—but not until weather safety issues are minimized. This is critical, because even after the primary weather event is over, other risks often remain in an area, including lightning, damaging winds, or flash flooding. Safety considerations are important. We help many utilities stage their resources directly outside of the impact zone, so that right after the dangerous weather ceases, they can get in and start restoration as quickly as possible.”

Porter noted that AccuWeather’s innovation in forecasting technology includes incorporating “artificial intelligence (AI), data analytics, and new delivery platforms. When extreme weather is on the way, we provide advanced lead time and highly detailed impact areas effectively showing the magnitude and scale of disruption.” Porter said AccuWeather’s Impact Indicator “combines historical weather data and property damage estimates into a unique algorithm that measures risk of various weather phenomena on a scale of 1 to 10. Utilities can use this proprietary index to plan and stay on top of the latest weather developments, to more clearly understand how a particular weather event will impact their location. Operations managers can use it to ensure employee safety and understand exactly how many workers might be impacted by a weather event.”

Engineering More Resilience

Technology plays a major role as utilities assess the risks of extreme weather on their operations. This may seem relatively new, but power generators have been researching ways to improve grid restoration and resiliency for decades.

“Power delivery systems, particularly distribution systems in the United States, whether they are overhead or underground, have always been vulnerable to the effects of major storms,” Lavelle Freeman, technical director in GE’s Energy Consulting Group, told POWER. “In fact, virtually every utility has had to respond to a major storm event in its history. Some utilities, because of their geography [areas prone to winter storms (Figure 2) or hurricanes], must deal with such events nearly every year.”

Figure 2 - SC National Guard - Jan 2016
2. Trees and power lines don’t mix. A winter storm along the U.S. East Coast in January 2016 caused plenty of damage and left thousands without power, including in South Carolina. Here, an electrical transformer burns and fallen trees block a road near Greenville and Travelers Rest. Source: U.S. Department of Defense/South Carolina National Guard photo by Army Staff Sgt. Roby Di Giovine 

The DSTAR organization—Distribution Systems Testing Application and Research—was formed more than 30 years ago, in part due to the Northeast Utilities (NU) group, which recognized an increased need for “investigation of distribution system phenomena and engineering considerations,” according to its website. Over the years, as equipment has evolved and reliability of the transmission grid has been a higher consideration, the group has expanded from its original five utilities and one utility organization, to encompass utilities across the U.S. The group has expanded its research to cover distribution system engineering and operations, and development of software tools. GE’s Energy Consulting Group leads the DSTAR consortium.

“Several years ago, the members of the DSTAR consortium commissioned a study of the best practices for utility storm response,” Freeman said. “The study examined the practices, procedures, and experiences of U.S. utilities during major storm occurrences with the goal of understanding and conveying what went right and what went wrong during the build-up, restoration, and ramp-down phases. The investigation included detailed utility surveys, interviews with storm bosses, vendors, and consultants; and reviews of reports, proceedings, and papers. The result is a comprehensive discussion of many important aspects of storm restoration with an emphasis on best practices and lessons learned from past experiences.”

Major storms in recent years have highlighted the importance of proactive measures to deal with weather disasters, including how to make the grid more resilient.

“One of the key findings from the report is that storm response begins long before an event occurs and continues long after the worst is over,” Freeman said. “Storm-hardening measures, in particular, aim to reduce the impact of future storms by assessing the infrastructure to identify ways to make it more resilient, [to] significantly improve the reliability and resiliency of grids to withstand extreme weather events.” He said other items noted by utilities include “preparing and training for storm restoration, early warning and tracking systems, damage prediction, activation and mobilization procedures, including staging, materials management and logistics, and clear damage assessment and deployment procedures.”

Power generators are taking advantage of DSTAR’s research to fine-tune their disaster response plans. “The research we’ve participated in as part of GE’s DSTAR consortium has provided us with future-ready solutions to emerging challenges on the distribution network, as well as insights into valuable current best practices in the industry, including storm preparedness and response,” said Michael Hyland, senior vice president, Engineering Services, for the American Public Power Association.

Damaging Bolts from the Blue

Lightning is a major cause of power outages. Bolts can strike equipment, taking it out of service; lightning strikes can fell trees, knocking them into power lines and cutting off electricity.

Melanie Scott, a lightning meteorologist and marketing manager, and Ron Holle, a meteorologist and consultant, are two members of the team at Vaisala, a global environmental and industrial measurement company headquartered in Helsinki, Finland, that has U.S. operations. They answered questions from POWER about some of the best practices utilities need to take to prepare and protect against lightning and other major weather events.

“Each utility has their own unique approach, policies, budget, and resources to evaluate and create a plan that best fits their organization,” wrote Scott and Holle. “Evaluating the risk of lightning and/or severe weather in the areas where the utility has infrastructure would be recommended.” The two said gathering historical lightning data for the utility’s region—there are several sources for the data, including the Vaisala National Lightning Detection Network (NLDN) in the U.S.—can help with research. The two said lightning data from the NLDN is used by many utilities to examine weaknesses in their infrastructure with regard to lightning, of particular importance as installations age.

“Vulnerabilities to lightning occur due to inadequate initial design, protection levels, and materials,” the two wrote. “The weak portions of installations, such as transmission and distribution lines, arrestors, poles, and transformers sometimes take years to appear. But knowledge of how much lightning has occurred at those locations is very effective in isolating what components are inadequate in withstanding future challenges due to lightning events.”

Many utilities employ in-house meteorologists tasked with supplying forecasts tailored to the generators’ territory and operations—different from your local television weather person.

“A utility meteorologist is focused on providing weather forecasts, information, and alerts to their staff for day-to-day operations, emergency operations, and pre- and post-storm situations,” wrote Holle and Scott. “These meteorologists will focus on the specific impact a storm will have on their system, including ‘weak spots.’ For example, if winds are a problem for an older section of the grid, then the utility meteorologist will know this and work with field crews or dispatch accordingly for monitoring the area and scheduling field crews when needed. They will also focus highly on safety of storm crews, when to deploy them, and when it is not safe for them to be out.”

“Meteorologists who work for utilities have a very different role than broadcast meteorologists,” said AccuWeather’s Porter. “Instead of serving the public and providing broad information, meteorologists who work for utilities provide tailored and extremely specific information for the utility’s operations. They assist with tasks ranging from load forecasting [see “Using Artificial Intelligence to Develop Electricity Load Forecasts” in this issue] to severe weather prediction, focused entirely on how the utility will be affected, and designing programs to minimize impact of weather.”

Predicting the Damage

The Atlantic Basin hurricane season has begun and runs through November, but even as a new season begins, the impacts of last year’s monster storms continue to be felt in the affected areas.

Puerto Rico felt the brunt of last year’s storms, particularly from Hurricane Maria. Reports say some rural areas of the island are still without power nearly nine months after the storm hit, and sporadic outages continue to pop up. Much of Puerto Rico’s power is still being supplied by generators provided by the U.S. Federal Emergency Management Agency.

“When a natural disaster like this [in Puerto Rico] happens, it is a priority to get reliable power back online as quickly as possible,” said Pereda of PW Power Systems, who noted that microgrids and pre-commissioned mobile gas turbine units are good for such situations because they can be rapidly deployed “to support critical facilities such as hospitals, water treatment plants, wastewater plants, and police/fire stations. These can also serve as ready backups to local substations that connect to the central grid.”

Puerto Rico, though, suffered due to aging power infrastructure, which—along with bureaucratic missteps—slowed the repair process. “For Puerto Rico, restoration is only a stopgap due to the aged energy infrastructure that exists,” Pereda said. “A commitment is needed to rebuild in a reliable, sustainable way that is resilient for the next big storm.”

Rebuilding to ensure resiliency requires information about the types of damage caused by different weather events. “Storm prediction is based on an accurate weather forecast of elements that can damage the electric distribution system. This could be inches of ice accumulation on trees and overhead equipment for ice storms (Figure 3), peak wind speed and gust durations for hurricanes, and strike proximity and frequency for lightning,” said GE’s Freeman. “Based on the history of storm damage, operational capability, and the susceptibility of the current design, expected damage and approximate crew requirements can be predicted.”

Figure 3 - frozen power lines
3. Resilience can be a weighty issue. These power lines show the effects of an ice storm, which can be devastating to above-ground transmission and distribution systems. Meteorologists have said a quarter-inch of ice accumulation can add 500 pounds of weight per line span. Courtesy: Freeimages.com 

Said Freeman: “Commercially speaking there aren’t many applications available for storm damage prediction,” though he cited OutageCast from DTN/Meteorlogix, built on technology from Kinetic Analysis Corp., as one option. “The future of weather prediction will likely be characterized by a trend toward more site-specific detailed forecast information. Research is ongoing at the NOAA [National Oceanic and Atmospheric Administration] National Severe Storms Laboratory, university centers, and commercial labs (such as IBM Research) where they are looking into ways to use modern computer technology to improve forecast accuracy and precision.”

The process is more than just about limiting the impact of extreme weather on electricity transmission systems. “When the power goes down, it isn’t just an inconvenience… people’s lives are at stake,” said AccuWeather’s Porter. “You can’t control the weather itself, but utilities can control how they monitor, plan for, and respond to severe weather events.” ■

Darrell Proctor is a POWER associate editor.