Folks who lived in Charlotte on Sept. 22, 1989, will remember it as the night Hurricane Hugo barreled through town, its 80 mph winds snapping trees, exploding electrical transformers and turning loose objects into missiles.
They will also recall the morning after: fallen trees and power lines strewn everywhere across houses, yards and streets. And the nights that followed in the dark, candlelit meals gleaned from refrigerator contents before they spoiled, cooked over charcoal grills and camp stoves.
Nearly 700,000 Duke Energy customers lost power during Hugo. The last unlucky ones didn’t get it back for three weeks.
But the next storm might lose some of its punch. Duke and other electric utilities are using data and digital technology to minimize power outages and recover more quickly from storms.
“The days of Hugo were very manual; operators had to go out in the field to make repairs,” said Jeff Brooks, a Duke spokesman. “Today the power grid is much more centralized and much more intelligent.”
Brooks compares new “self-healing” grid technology, for example, to a car’s GPS system that can detect accidents on the road ahead and reroute drivers around them. Duke says the technology prevented 80,000 extended outages when Hurricane Florence hit the Carolinas last September, and about 12,000 outages during Hurricane Dorian this month.
In some cases, utilities can prevent power outages by identifying potential problems in advance. Isolated communities supplied by a single, damaged power line might soon turn to backup power stored in batteries from solar-powered microgrids when storms strike.
The Electric Power Research Institute, a nonprofit whose members include many U.S. electric utilities and has a location in Charlotte, probes for new ways to prepare for and recover from storms.
Drew McGuire, EPRI’s program manager for distribution research and development, groups technological advances into three categories. Among utilities, distribution refers to the lines and other equipment that deliver electric power to consumers.
- Distribution automation systems can now detect and react to problems as they occur — a tree falling across power lines, for example — and isolate them to reduce the number of customers affected and alert repair staff. A Department of Energy study last year estimated that utilities will have quadrupled their spending on automation between 2014 and 2024.
- Hardening of physical structures, such as power poles, aims to create designs with more predictable failure points when falling trees strike them. That could mean stouter power poles but also new designs for the structures and hardware mounted to them.
“If you can keep the pole standing up but the crossarm breaks, that’s a much faster repair,” McGuire said.
- Storm recovery technology now includes a potentially powerful tool: drones. They’ve come on the scene among utilities only in the past couple of years, and offer the ability to assess damage faster than ever and with more data. EPRI and utilities are still learning how to use drones most effectively and are answering questions about their limits, such as whether they can be used at night.
More technology research is underway, McGuire said. Composite materials can be lighter and stronger than those used now. Augmented reality, which superimposes computer-generated images on real world objects, giving utility workers the ability to send and receive data while in the field, is being tested. Sensors deployed across the grid could offer an enhanced ability to see what’s happening in real time as storms move through.
“The theme is more data ahead of time, and once you get your people in the field, to continue that data flow,” McGuire said.
Hugo was a warning
Duke Energy says the stunning intensity of Hurricane Hugo, so far inland, served as motivation for improving its storm responses. Losing power was inconvenient 30 years ago. Today, with ever-growing reliance on electricity, it can be catastrophic.
Duke proposed a 10-year, $13 billion grid modernization program for North Carolina in 2017 that would have included some storm-response upgrades. The N.C. Utilities Commission rejected the proposal, but Duke plans to try again this fall with a three-year grid improvement strategy that will be part of rate cases in the Carolinas.
The strategy would build on measures Duke has recently begun using, or testing, to avoid outages and restore them faster. There’s some urgency to deploy the new tools, Duke says, because damaging storms are striking the Carolinas more often and with greater intensity.
Duke is installing new barriers around substations that are most likely to flood, especially in eastern North Carolina. It’s hardening power poles and lines, at times replacing wood with steel, to help them withstand high winds and storm-tossed debris. It’s burying power lines in places where outages regularly occur and has begun to use drones to assess storm damage.
Digital technology, meanwhile, floods the utility with data it never had before. The data can tell Duke which quarter-mile section of a 10-mile power line is the least reliable and predict whether a troublesome transformer should be replaced before it fails. And it helps outside repair crews — workers came from as far as Canada during Hurricane Florence — quickly understand problem areas.
“It allows us to have a near real-time blueprint of how our grid operates,” Brooks said. “With the blueprint we have, we know exactly how the grid is configured so we have a blueprint of how to build it back.”