Grid Responders Gain Insights Battling Harvey, Irma and Maria
By Rod Walton. Senior Editor
Harvey crashed the south Texas shoreline on a Friday night in late August, lashing out at homes, businesses and power grid for days on end. The unrelenting rain that hovered for nearly a week after the hurricane’s landfall was worse than the wind. Ultimately, the storm caused more than 1 million outages, killed nearly 100 people directly or indirectly and racked up a record $200 billion in economic losses, according to reports.
A relatively small entity like Nueces Electrical Cooperative (NEC) might have been lost in the wave of media coverage from Corpus Christi to Houston and beyond. But Harvey certainly didn’t miss NEC, taking down 24 poles, eight substation feeders and one entire substation by Saturday morning and leaving some 8,200 members-or almost half of the system-without power.
All politics is local, the saying goes, and electricity service is no different. NEC’s numbers may have paled in comparison to those hit by CenterPoint Energy’s customers in Houston, Florida Power & Light’s damage after Hurricane Irma hit and, of course, the grid destruction wrought by Maria in Puerto Rico. But the impact is the same to those customers who lose power while a dark and angry force wails past them, causing fear and uncertainty.
The utility’s job, no matter how big or small, is to reintroduce certainty into the grid as quickly and seamlessly as possible. Mission accomplished in Nueces.
“Thankfully, with the hard work of our team, NEC employees were able to restore power to 95 percent of our members within 24 hours, and 100 percent within 48 hours,” said NEC IT Director Sergey Seryogin. “This meant that the majority of members that had evacuated the area due to the storm already had their power back on by the time they returned home.”
This was not the norm during Harvey or any other hurricanes which devastated much of the U.S. Gulf Coast and the Caribbean islands in 2017. Restoration times varied according to point of impact and duration of wind and rain, but most utilities needed days and even weeks to get power back on.
Triple Whammies and Worse
Forgive the pun, but 2017 could prove to have been a watershed year in the annals of damage assessment by utilities. Consider what happened just in the U.S. : They saw more fire and rain in 2017 than any utility planner cares to ever see again. Chances are they will see it again, so these crises provide useful information for the ages, or until the next big storm comes along. Superstorm Sandy blistered the upper East Coast in 2012, forcing some hard lessons, as well.
“They then designed substations that are so much more hardened and resistant to high winds. These are critical nodes for operation. If you can make sure those are ready, it’s easier to restore power.”
Juan de Bedout, chief technology officer of GE’s Grid Solutions business
“Look at how Sandy wreaked havoc in New York, flooding distribution substations,” recalled Juan de Bedout, chief technology officer of GE Power’s Grid Solutions business. “They then designed substations that are so much more hardened and resistant to high winds. These are critical nodes for operation. If you can make sure those are ready, it’s easier to restore power.”
New York’s grid planners have been busy on such work ever since Sandy. In many cases, however, the intensity of improving infrastructure dissipates with time. “Memory takes over until the next big event,” de Bedout noted.
Few will forget the triple whammy of Harvey, Irma and Maria anytime soon in the Americas. Total outages topped 12 million, entire grids virtually destroyed and, worst of all, close to 800 lives lost. Some slices of the devastation were larger than others, of course, but every sector hit was hit hard.
NEC’s Seryogin learned that one thing is relatively universal-the more communication, the better. Those affected are usually understanding about restoration struggles, but they want to know where, when and how long. The cooperative benefited from its new Sensus advanced metering infrastructure (AMI) system, allowing it to see real-time outages down to specific smart meters.
“Our larger outages affecting that largest number of people are prioritized first and then nested outages that impact individual customers are addressed next,” he said. “In the past, customers with these nested outages would often have to call us to let us know their power was still out after the majority of homes and businesses around them had been restored, as our system would not have registered the outages.”
AMI changes all that with an ever-pinging flow of data-and even interruptions are located and dealt with as time allows for the crews out there. It also eliminates the old time-wasting uncertainty that forced crews to travel up and down lines looking for problems.
The best first step in assessing damage, NEC’s Seryogin pointed out, is gathering as much data as possible right up front. This helps to prioritize restoration efforts based on scope and need.
“In our case, once the winds died down from the storm overnight, the data we had allowed us to dispatch crews and start the restoration process immediately at 9 a.m. Saturday morning,” he said. “With our outage management system and AMI system, we were able to pinpoint exactly where crews needed to be sent to efficiently restore power to the greatest number of people.”
A New Era of System Visibility
The hurricane season of 2017 certainly was unforgettable, but it may be part of a longer weather trend that will prove troublesome for even the most advanced utility grids. A 2014 Climate Central study (Figure 1) found that annual weather-related power outages doubled between 2003 and 2012 in the U.S. alone. Those include ice storms in Oklahoma, sudden wind and snow fronts in Oregon and, of course, the superstorm which attacked the east coast. An American Society of Civil Engineers report estimated that the U.S. gross domestic product will fall $1.9 trillion by 2040 if power outages continue at the same rate. By way of comparison, nearly $2 trillion is more than 10 percent of the average U.S. annual GDP.
Dealing with the weather is another issue, but utilities clearly have financial incentives to respond and restore as quickly and efficiently as possible. GE’s Bedout notes that, yes, the storms are getting more frequent, but the tools used to deal with them are getting better all the time.
“Historically, when you look at outages at the distribution level, there were a lot that were slow to restore. The reason was lack of visibility,” he said. “Matter of fact, when you’d look at a distribution system that had some type of fault, much of the circuit likely was healthy, but just a portion was unhealthy.”
Distribution automation coupled with fault protection, isolation and restoration tools is evening the score. When crews have visibility along the line they isolate the portion of the circuit and fix it while the rest remains up and running. As he noted, sensors give you eyes while reclosers and switches allow you to reconnect the healthy portion of the circuit.
“Our customers are finding that healthy portions can be restored within minutes,” Bedout said. “It helps the utility in terms of reliability metrics.”
And utilities certainly helped each other in the wake of Harvey, Irma and Maria. More than 10,000 workers from 21 states arrived in south Texas to help CenterPoint Energy, AEP Texas and various cooperatives deal with Harvey’s lingering impact, while Pepco and many others rushed into the southeastern U.S. to help Florida Power & Light, Georgia Power and Duke reconnect customers after Irma.
Island within the Island
What Hurricane Maria did to Puerto Rico and other Caribbean islands is another level altogether. Puerto Rico is a singular example, GE’s Bedout noted. Most of the island’s load is concentrated in the northern part, while centralized generation was mostly in the south. Knocking out the transmission lines that connected both halves basically severed the grid there.
“This is a perfect example of the call for a more hybridized generation system” combining traditional power plants with dispersed, distributed and renewable resources combining solar and microgrids, for example, he said. “This can help restore it at critical levels.”
Systems which can island within the island, so to speak, may prove crucial. But no utility is an island, completely, and these storms seem to be getting worse and more frequent in the short term. Readiness reigns supreme.
“More than ever, this season reminded us that when disaster strikes, there has to be a plan in place,” said Randolph Wheatley, vice president of marketing at Sensus, which was NEC’s AMI partner. “Technology can be an essential enabler for utilities to quickly assess damage, make critical decisions and communicate restoration news to customers.”
How utilities handled the storms will be a featured part of the upcoming DistribuTECH Conference and Exhibition in San Antonio later this month. “Harvey, Irma and Maria: How the Grid Responded to a Hurricane Season for the Ages” will be a two-hour session beginning at 1:30 p.m. Thursday, Jan. 24. It will feature CenterPoint, AEP Texas, FP&L and others talking about their experiences and what they learned in the effort. | PGI