Hurricane Sandy has now made landfall along the central coast of New Jersey, and utility companies up and down the U.S. Eastern seaboard are scrambling to keep the lights on. Over the weekend, I spoke with Nicholas Abi-Samra, a 35-year veteran of the power industry and an expert on the effects of extreme weather on the electricity grid, to see how companies have been gearing up for this massive storm. Abi-Samra, chair of the IEEE Power & Energy Society’s San Diego chapter, is vice president of asset management at Quanta Technology, an energy consulting company headquartered in Raleigh, N.C.

Spectrum: From a grid operator’s perspective, what’s the biggest concern right now?

Nicholas Abi-Samra: This storm is packing three threats: high wind (even gale force), heavy rain, and high surges. High winds—and specifically their ability to bring down trees and produce airborne debris—are a threat to transmission and distribution lines and also to electricity poles. Studies show that tree-related failures increase exponentially when wind speeds are over 60 mph [100 km/h]. [At 9:00pm EDT on 29 October, Sandy had maximum sustained winds of 80 mph or 130 km/h.] Wind may cause conductors to slap together and short out. The fact that trees have not lost their leaves yet in a number of areas in the predicted path of the storm is a big concern, because they’re much heavier than bare branches, and so their impact on a power line or pole will be much greater. When you add rain, the leaves and branches become even heavier. Wind may blow tree limbs or entire trees into or across lines, either knocking them down and breaking them, or knocking them into each other and causing faults and interruption of service.

In the past 10 years, most utilities have made great strides in vegetation management—removing dead or diseased trees, so-called “hazard trees”—along their right-of-ways [the land immediately surrounding power lines and poles]. But in high wind situations, risk from airborne debris from trees outside the right-of-way (both “hazard” trees and normal-looking trees) can exceed the risk of trees within the right-of-way by a factor of 3 or even 4 to 1. This kind of secondary damage is really the prevalent cause of damage in many storms.

The expected storm surge is phenomenal, well above Hurricane Irene at the highest. And the storm’s coverage is way more extensive, as far west as Pittsburgh, so even lakes will be hit with high waves. Generating plants downstream from reservoirs or dams could be vulnerable. Flooding should be of concern to operators of coastal energy facilities, such as oil refineries and nuclear power plants. It’s not just power plants that might be affected, but also industrial facilities and of course residential areas.

Spectrum: What kinds of precautions do grid operators take at such times?

Nicholas Abi-Samra: Many utilities will take preemptive steps like shutting down some of their energy assets so that they can contain the damage. They will suspend routine and scheduled maintenance work and restore essential equipment that can be put back in service. They’ll move to storm operation mode, and they will arrange an off-site emergency communications control center just outside the storm area, in case it becomes too dangerous to remain on site. They’ll increase real and reactive reserves, have diesel-driven emergency generators at critical sites, and have emergency generators available for the pumps (and other important loads). They’ll also prepare for storm-related flooding, for example, by putting out sandbags.

For generator stations that are vulnerable to flood or sea-level surge, they’ll reduce the power output and be prepared to do a controlled shutdown of generating units ahead of the storm surge, to minimize damage and downtime. They’ll also be prepared to operate the units as an “island,” disconnecting from the rest of the grid, if all transmission is lost.

And they’ll take general precautions, like emptying and then securing dumpsters around substations, topping off the fuel tanks in utility vehicles, and making sure workers have spare batteries for their cell phones, since recharging may not be possible.

You really can’t do much about hardening the system at this point in the storm—and you can never harden 100 percent against extreme weather. Restoration is the important thing now, how to patch the system back together and minimize the outages resulting from Sandy. The affected utilities are getting assistance from other utilities. I know that employees from some of the west coast utilities, including here in San Diego, are deploying to the east. Our company does storm assistance, and we were contacted by some utilities as early as last week. And workers are coming in from neighboring states with trucks and tools, which is great. From past events like Hurricane Katrina, we know that mutual assistance is the king in terms of getting back on line. Otherwise you’re talking about outages that can last for weeks.

After Sandy, each utility will have to analyze the performance of its assets and how they fared. 

Spectrum: You written about the dangers of substation flooding. Why is that a big concern and why is it so costly and difficult to recover from that kind of event?

Nicholas Abi-Samra: A power substation is basically a place where you get the power from the transmission grid and distribute it to the distribution feeders and hence the end users. You have a number of components all concentrated in the same place: power transformers, breakers, capacitors, and so on. The breaker (and its associated relays) is a form of protection, designed to break fault current—the large volume of current that flows when a fault is detected on the system. It also has a secondary function, allowing the system operator to switch circuits in and out. You also have a lot of lead-acid batteries on site. And there’s the control house, which is the brains of the substation, with a lot of electronic and computer equipment. So a substation is a concentration of equipment that’s essential for the operation of the grid. Floods may inundate substations, and some utilities may be forced to shut them down to prevent major damage to the equipment, and therefore accelerate the restoration after the storm.

Trying to get the substation back in service is a very lengthy and laborious process, much more so than replacing a broken pole after a wind storm. And if you lose a number of stations at the same time, that’s obviously much worse.

In a substation, even minute quantities of moisture and dirt contamination can render some electric equipment inoperable or lead to catastrophic failure. After a flood, large amounts of water and mud can remain trapped, making repair a sizable task and lengthening the restoration task. For example, if a breaker is submerged for a long time, it’s necessary to completely disassemble the mechanism and clean each part. That means all the bearings, pins, cylinders, rings, latches, and triggers.

Repairing a transformer can also be a lengthy and expensive process. It takes anywhere from 18 months to a couple years to get a new transformer. This is why in an event like this some utilities try to minimize the number of energized transformers and thus decrease the risk of a damaging close-in short circuit (or fault) caused by flying debris.

Spectrum: Are grid operators better prepared for severe storms than they were, say, five years ago?

Nicholas Abi-Samra: Yes, they are. Today we see better communication between the utilities and their work crews and customers. A number of utilities are using storm-tracking software. And they have much better situational awareness of where the outages are and what needs to be done to bring things back online. In the past, you’d have to call the utility and report a problem; now it’s automated. And utilities are much better at taking the lessons learned from past storms and figuring out how to restore the system as quickly as possible.

Spectrum: How can smart grid technology help in preventing or recovering from storm power outages?

Nicholas Abi-Samra: A smart grid introduces automation so that you don’t need somebody to go and close a switch or breaker. And if you have an area that has a fault, the system is designed to isolate that area and then restore power automatically. You may have heard the term “self-healing”: that means the system can reconfigure itself to deal with outages. At the moment, that works best if you just have a limited event, like the failure of just one feeder—it can automatically switch to another feeder. But when the problem is larger, it won’t be as effective. The smart grid will however speed up system restoration.

There are logical limits. Remember that the smart grid is not replacing the existing electricity infrastructure, and in many cases [in the United States] those systems are well beyond their expected service life. You have some utility poles that are more than 80 years old, for example. A smart grid cannot fix an old transformer or a utility pole that has been there for 80 or 90 years. And as electrical equipment and systems get older, they deteriorate, leading to higher failure rates and making them unable to perform as needed during periods of high stress, such as extreme events like Sandy.

PHOTO: FirstEnergy Corp.

UPDATE: This post was revised at 10:45pm on 29 October 2012.

 

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This photograph shows a car with the words “We Drive Solar” on the door, connected to a charging station. A windmill can be seen in the background.

The Dutch city of Utrecht is embracing vehicle-to-grid technology, an example of which is shown here—an EV connected to a bidirectional charger. The historic Rijn en Zon windmill provides a fitting background for this scene.

We Drive Solar

Hundreds of charging stations for electric vehicles dot Utrecht’s urban landscape in the Netherlands like little electric mushrooms. Unlike those you may have grown accustomed to seeing, many of these stations don’t just charge electric cars—they can also send power from vehicle batteries to the local utility grid for use by homes and businesses.

Debates over the feasibility and value of such vehicle-to-grid technology go back decades. Those arguments are not yet settled. But big automakers like Volkswagen, Nissan, and Hyundai have moved to produce the kinds of cars that can use such bidirectional chargers—alongside similar vehicle-to-home technology, whereby your car can power your house, say, during a blackout, as promoted by Ford with its new F-150 Lightning. Given the rapid uptake of electric vehicles, many people are thinking hard about how to make the best use of all that rolling battery power.

The number of charging stations in Utrecht has risen sharply over the past decade.

“People are buying more and more electric cars,” says Eerenberg, the alderman. City officials noticed a surge in such purchases in recent years, only to hear complaints from Utrechters that they then had to go through a long application process to have a charger installed where they could use it. Eerenberg, a computer scientist by training, is still working to unwind these knots. He realizes that the city has to go faster if it is to meet the Dutch government’s mandate for all new cars to be zero-emission in eight years.

The amount of energy being used to charge EVs in Utrecht has skyrocketed in recent years.

Although similar mandates to put more zero-emission vehicles on the road in New York and California failed in the past, the pressure for vehicle electrification is higher now. And Utrecht city officials want to get ahead of demand for greener transportation solutions. This is a city that just built a central underground parking garage for 12,500 bicycles and spent years digging up a freeway that ran through the center of town, replacing it with a canal in the name of clean air and healthy urban living.

A driving force in shaping these changes is Matthijs Kok, the city’s energy-transition manager. He took me on a tour—by bicycle, naturally—of Utrecht’s new green infrastructure, pointing to some recent additions, like a stationary battery designed to store solar energy from the many panels slated for installation at a local public housing development.

This map of Utrecht shows the city’s EV-charging infrastructure. Orange dots are the locations of existing charging stations; red dots denote charging stations under development. Green dots are possible sites for future charging stations.

“This is why we all do it,” Kok says, stepping away from his propped-up bike and pointing to a brick shed that houses a 400-kilowatt transformer. These transformers are the final link in the chain that runs from the power-generating plant to high-tension wires to medium-voltage substations to low-voltage transformers to people’s kitchens.

There are thousands of these transformers in a typical city. But if too many electric cars in one area need charging, transformers like this can easily become overloaded. Bidirectional charging promises to ease such problems.

Kok works with others in city government to compile data and create maps, dividing the city into neighborhoods. Each one is annotated with data on population, types of households, vehicles, and other data. Together with a contracted data-science group, and with input from ordinary citizens, they developed a policy-driven algorithm to help pick the best locations for new charging stations. The city also included incentives for deploying bidirectional chargers in its 10-year contracts with vehicle charge-station operators. So, in these chargers went.

Experts expect bidirectional charging to work particularly well for vehicles that are part of a fleet whose movements are predictable. In such cases, an operator can readily program when to charge and discharge a car’s battery.

We Drive Solar earns credit by sending battery power from its fleet to the local grid during times of peak demand and charges the cars’ batteries back up during off-peak hours. If it does that well, drivers don’t lose any range they might need when they pick up their cars. And these daily energy trades help to keep prices down for subscribers.

Encouraging car-sharing schemes like We Drive Solar appeals to Utrecht officials because of the struggle with parking—a chronic ailment common to most growing cities. A huge construction site near the Utrecht city center will soon add 10,000 new apartments. Additional housing is welcome, but 10,000 additional cars would not be. Planners want the ratio to be more like one car for every 10 households—and the amount of dedicated public parking in the new neighborhoods will reflect that goal.

This photograph shows four parked vehicles, each with the words \u201cWe Drive Solar\u201d prominently displayed, and each plugged into a charge point.Some of the cars available from We Drive Solar, including these Hyundai Ioniq 5s, are capable of bidirectional charging.We Drive Solar

Projections for the large-scale electrification of transportation in Europe are daunting. According to a Eurelectric/Deloitte report, there could be 50 million to 70 million electric vehicles in Europe by 2030, requiring several million new charging points, bidirectional or otherwise. Power-distribution grids will need hundreds of billions of euros in investment to support these new stations.

The morning before Eerenberg sat down with me at city hall to explain Utrecht’s charge-station planning algorithm, war broke out in Ukraine. Energy prices now strain many households to the breaking point. Gasoline has reached $6 a gallon (if not more) in some places in the United States. In Germany in mid-June, the driver of a modest VW Golf had to pay about €100 (more than $100) to fill the tank. In the U.K., utility bills shot up on average by more than 50 percent on the first of April.

The war upended energy policies across the European continent and around the world, focusing people’s attention on energy independence and security, and reinforcing policies already in motion, such as the creation of emission-free zones in city centers and the replacement of conventional cars with electric ones. How best to bring about the needed changes is often unclear, but modeling can help.

Nico Brinkel, who is working on his doctorate in Wilfried van Sark’s photovoltaics-integration lab at Utrecht University, focuses his models at the local level. In his calculations, he figures that, in and around Utrecht, low-voltage grid reinforcements cost about €17,000 per transformer and about €100,000 per kilometer of replacement cable. “If we are moving to a fully electrical system, if we’re adding a lot of wind energy, a lot of solar, a lot of heat pumps, a lot of electric vehicles…,” his voice trails off. “Our grid was not designed for this.”

But the electrical infrastructure will have to keep up. One of Brinkel’s studies suggests that if a good fraction of the EV chargers are bidirectional, such costs could be spread out in a more manageable way. “Ideally, I think it would be best if all of the new chargers were bidirectional,” he says. “The extra costs are not that high.”

Berg doesn’t need convincing. He has been thinking about what bidirectional charging offers the whole of the Netherlands. He figures that 1.5 million EVs with bidirectional capabilities—in a country of 8 million cars—would balance the national grid. “You could do anything with renewable energy then,” he says.

Seeing that his country is starting with just hundreds of cars capable of bidirectional charging, 1.5 million is a big number. But one day, the Dutch might actually get there.

This article appears in the August 2022 print issue as “A Road Test for Vehicle-to-Grid Tech.”

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