How To Save The Electrical Grid

Dark Night When Hurricane Sandy hit New York City on October 29, 2012, most of Lower Manhattan lost power. Iwan Baan/Reportage by Getty Images

The explosion lit up the Manhattan skyline. A sudden boom, a one-two punch of yellow light—then everything went black. After Hurricane Sandy shoved water into Con Edison’s 14th Street substation in October, causing electricity to arc between capacitors, about a quarter million customers were left in the dark. Video of the high-voltage spectacle quickly went viral: It became an early, brilliant symbol of the massive storm system’s most pervasive and inescapable affront—a total and lingering loss of power. Across the U.S., as far west as Indiana and from Maine to North Carolina, Sandy caused hundreds of other mass outages. A tree blown down, wires ravaged by wind, a flooded power facility—each event had rippled out to affect homes far from the point of failure. The blackouts continued for weeks afterward, thwarting the region’s recovery.

While the duration of Sandy’s outages was unusual, their breadth—more than eight million homes in 21 states ultimately lost power—has become disturbingly common. In 2011, Hurricane Irene cut electricity to about 5.5 million homes. Tornadoes, ice storms, wildfires, and drought now routinely overwhelm the nation’s aging electrical infrastructure, inflicting sweeping blackouts. In the early 1990s, the U.S. experienced about 20 mass outages a year; today it’s well over 100. A 2012 Congressional Research Service report attributes much of the rise to an increase in extreme weather events. It also states that storm-related power failures cost the U.S. economy between $20 billion and $55 billion annually.

A century ago, when the foundation of today’s power distribution system was laid, electric appliances were just beginning to enter homes. Over time, the nation’s power use has skyrocketed, and so has the population. Demand is now rising at 1 percent a year, pushing more electricity through lines that were never intended to handle such high loads. “We sometimes joke that if Alexander Graham Bell woke up tomorrow and saw my phone, he’d be astounded,” says David Manning, executive director of the New York State Smart Grid Consortium. “If Thomas Edison woke up tomorrow and saw the grid, he could not only recognize it, he could probably fix it.”

A modern grid, capable of creating and delivering efficient, reliable power even in the midst of disaster, is long overdue. Such infrastructure would be more resilient to both storms and terrorist attacks, which the National Research Council warned in November could cripple entire regions of the country for months. Many of the necessary upgrades already exist: They’ve been developed in labs and demonstrated in smart-grid projects across the country. Other steps just require common sense.

STOP CASCADING FAILURES

A single tree felled by a storm like Sandy can cut off power to thousands.The existing U.S. electric grid has a linear structure. Large power plants, typically located far from the customers they serve, produce most of the electricity. Transformers at the plants increase the voltage so it can be moved more efficiently to local substations, which reduce the voltage and send it out to neighborhoods and individual homes. When a fault current, or surge, occurs anywhere along the line, automatic circuit breakers open to halt it. That’s why a single felled tree can cut power to thousands of customers. And that’s how overgrown trees brushing high-voltage lines in Ohio could black out 50 million people along the East Coast in 2003.

One way to reduce the impact of any individual failure is to replace the linear structure with a looped one. Imagine a power line studded with five smart switches that connects back to a substation on both ends. A tree hits the line. In the old, linear system, all the customers beyond the fault point would lose power; the utility would send out a work crew to search for the cause. In the new system, switches on both sides of the fault could isolate the problem and only customers between the two switches would go dark. Then, “those switches communicate and say, ‘It’s right here, come and fix me,’ ” says John Kelly, executive director of the nonprofit Perfect Power Institute.

Communities such as Naperville, Illinois, and Chattanooga, Tennessee, which are among the most advanced in the U.S. when it comes to smart-grid adaptations, have already installed looped systems and demonstrated their advantages. “You’re looking at 50 to 80 percent improvements in reliability,” Kelly says. Also, “you’ve limited the problems. You know right where to go, so now you can get those few customers back up quicker.”

Another way to stop failures from cascading is to install a fault-current limiter, or what University of Arkansas engineer Alan Mantooth calls a “shock absorber for the grid.” He’s developing the refrigerator-size device at the university’s National Center for Reliable Electric Power Transmission. “As bad things happen, circuit breakers just start opening and the lights go out,” Mantooth says. Rather than simply stopping the electrical surge altogether, his machine can absorb the excess current and send a regulated amount down the line.

Utilities have been slow to adopt looped systems, even though smart switches were developed in the 1990s. Florida Power and Light, whose customers experienced multiple hurricanes in the early 2000s, was among the first to do so. “Most utilities are very averse to change,” Kelly says. “And part of it is the monopoly structure that impedes innovation and improvement.”

When large-scale change does come, it will likely arrive in high-demand areas first. “In urban centers like New York City and Los Angeles, their fault currents are getting so high that they’re having to start replacing all of their circuit breakers,” Mantooth says. A fault-current limiter would be a practical solution. “We would insert this guy into the grid,” he says, “leave the existing circuit breaker, and limit the current so that the breaker is not overwhelmed.” The new equipment helps the old equipment remain in service for longer, a much more cost-effective approach than replacing all the breakers.