Newsweek: Want to Reduce Power Outages? Move Grids Underground, Says Energy Expert

Outages caused by blizzards and winter storms have killed thousands in recent years, most famously plunging 11 million people in Texas into freezing darkness for several days in 2021, killing as many as 700 people. Summer outages during heat waves, meanwhile, have also proven lethal.

As temperatures rise and weather gets more extreme, the problem is almost certain to get worse. Between 2013 and 2021, the average duration of a power outage in the U.S. doubled from approximately three-and-a-half hours to more than seven hours, while the frequency of outages increased from 1.2 to 1.42 events per customer per year. Weather-related power outages have increased by almost 80 percent since 2010. Meanwhile, an estimated 70 percent of transmission lines are more than 25 years old, making them increasingly unreliable, even under normal circumstances.

Few people are better positioned to suggest solutions to this burgeoning crisis than Peter Larsen, an applied economist who leads the Energy Markets & Policy department at Lawrence Berkeley National Lab, part of the U.S. Department of Energy (DOE). Larsen has worked for two decades to quantify the costs and benefits of both continued inaction and modernization.

He spoke with Newsweek about the challenges and the trade-offs facing regulators, energy providers and consumers in the age of extreme weather. This interview has been edited and condensed for the sake of length and clarity.

Newsweek: Why are there so many power outages?
Larsen: You cannot make a power system perfectly reliable because the costs could not be borne by the customers. It’s just not possible. So utilities have always struggled with this issue. What’s new is that with these natural hazards, and for that matter, some of the cybersecurity or physical security of power systems, the risks are increasing.

There are, in many cases, more frequent intense storms. And utilities are being asked to make even bigger investments in the power system to hedge the risk from some of these increasingly severe events. So then you have this challenge of trying to balance the costs against making a system more resilient. And it’s a push and pull between regulators, consumer advocates and utilities to strike that right balance.

Some have suggested moving the nation’s power grid underground. You’ve often been an advocate of this approach. Why?
My colleagues at Berkeley have shown that more than 90 percent of power interruptions occur at the local distribution level, with the lines that feed neighborhoods typically being the ones that go down. And so having more of those lines underground makes intuitive sense. But I also have a pretty unique perspective, because I came to the DOE from Alaska where the situation is, in some cases, pretty dire. The environment is changing extremely fast up there, and they’ve been dealing with problems we are only just now beginning to see in the lower 48.

At one point, I had the opportunity to study rural utility systems across Alaska, and traveled to more than two dozen communities over the course of two years on a Department of Energy grant. I saw power poles that were tilting at 45-degree angles with the lines in some cases snapped off, and when I talked to the local community, they were basically pointing out that the permafrost had thawed underneath the pole and the pole had sagged and essentially snapped the line.

But I also saw some solutions. In particular, I visited a relatively small fishing village called Cordova, Alaska, which, back in the late ’70s determined as a community they wanted to go a hundred percent underground. I ended up collecting data for about a year and concluded the decision almost eliminated the risk of power interruptions. For every dollar the community spent to go underground, they got back $16 in value. Afterwards, and this was about 10 years ago, I started to do a deep dive on undergrounding.

What did you find?
Everybody was talking about how costly undergrounding was, but no one was talking about what are the benefits that you get because you have more underground power. One of the variables I have tracked is the share of line-miles that each utility has underground. Looking at between 150 to 200 utilities I tracked, I discovered a statistically significant signal—utilities that had a larger share of their power system underground tended to have better reliability than those that had lower percentages of line-miles underground.

It’s helped build up that side of the equation to potentially make the case for that type of investment. Since then, the costs have come down dramatically. Five to 10 years ago, the costs for undergrounding were five to 10 times what it costs just to build an overhead system. But in recent years, the cost has really come down, in some cases to the point where they are becoming on par with overhead lines.

What has caused the costs to come down?
A lot of techniques developed in the oil and gas and water industries, are now being used for undergrounding. One of them is directional boring, which allows you to have a smaller footprint to create the trench or create the space where you’re going to lay the underground cable. You can be further away and access areas without actually having to bring the machinery in the whole route. You can just come in from the side, send a directional border in, and not have to go through and lay some big trench through someone’s private property.

The other thing that’s happened is back in the old days, the conduit, which is basically that sheath that you put the power line in, used to be plastic and rigid, and then it would crack, and then water would get in there, and then the power lines would short. Now they’re using some pretty sophisticated materials, different types of rubbers that are basically impervious to water and breaking. So not only the materials being used has improved significantly, but you’re able to get costs down.

Can we expect to see power poles disappear?
A number of places that are facing severe weather risk from hurricanes are implementing major programs to underground large sections of their power system. And other communities, especially those out west, are primarily motivated to underground to reduce the risk of causing wildfires in the first place. After the big fires in California, where the power system was essentially one of the culprits, PG&E announced they were going to underground 10,000 live miles of power lines to try to minimize risk and increase resilience, which is a very significant effort. It’s tens of billions of dollars to do that.

Florida Power & Light has been a pioneer in this area. They’re doing billions of dollars’ worth of undergrounding. Dominion Energy up in Virginia had a goal, I think, of undergrounding about 4,000 miles. To pay for it, each customer in Dominion pays $2.50 per month, and that would help Dominion essentially underground 4,000 line-miles.

But every utility jurisdiction, every collection of customers, electricity customers, have their own unique needs. Undergrounding may be a solution, maybe the best solution in some places, and in other places it may not be the best solution. I like to think of these things a little bit more holistically, that there’s a suite of things that could be done in any given location. Undergrounding just might happen to be one of them.

What are some of the other solutions?
Simple vegetation management. Utilities going out and trimming trees. That’s a big one. It’s not sexy, but trees falling on lines is one of the top causes of power interruptions. Another one is hardening infrastructure. So that could include making poles, power poles, able to withstand higher wind speeds. You can use different materials. If you’ve been down in the Caribbean or the tropics, you see in some cases cement poles. That’s kind of the extreme. That wouldn’t necessarily be cost effective in a lot of places, but they experienced some pretty significant wind speeds with hurricanes and so forth. So that’s another example.

Or you could move infrastructure entirely, like moving a substation, entirely above the flood plane. A couple of years ago, there was a substation in Manhattan, the East 13th substation, that flooded and essentially exploded. You can watch the clip on YouTube. It looks like a star exploding. Consolidated Edison, or ConEd, put in a bunch of infrastructure enhancements to prevent it from flooding in the future. They moved the control room and they put some other flood protections around it.

Other things you can do, especially in wildfire prone areas, is you can put covered conductors and other types of insulation on the line that help minimize the potential for a power line causing a fire, by igniting wildfires during dry seasons. In addition to undergrounding lines, PG&E is following some of these other strategies, like vegetation management and covered conductors.

You’ve said that some power interruptions now are different from those we have seen in the past. Can you expand on that?
As I mentioned, historically, power outages almost always occur at the distribution level, [for] the local level line serving the neighborhood to get knocked over because of a windstorm hitting a tree. Now, increasingly we also have to worry about system-wide issues. You are going to see interruptions occurring further up the supply chain than the local distribution line serving your neighborhood.

What happened in Texas in 2021, for instance, when a winter storm that same year left 11 million people in Texas without power because the power plants weren’t able to get gas because of freezing up issues. I live in the northwest. If you have a persistent drought and you have hydroelectric resources not able to generate to their full capacity, and you have a problem, it goes beyond just one utility because you have many utilities that rely on hydroelectric power.

If you have an extended drought—as we will in the west—that’s not a problem at the neighborhood level in terms of a power line. That’s a problem that impacts all customers, in some cases across many different states simultaneously. And that’s something that I think we’re going to see more of in the future. That could mean more frequent, longer-lasting power outages and potentially significant increases in costs to customers.

What can we do about that?
The other transformation we’re making is we’re transitioning away from the days of the bulk power system where there’s a power plant, it sends power on a transmission line, and then it could step down into your neighborhood on a little local line. We’re trending away from that towards what we call more distributed energy systems. These can be neighborhood microgrids or homes with solar and battery storage. So in the future, I think things are going to be much more distributed than they have been in the past.

[Customers are also] getting great incentives from the government to offset some of the costs. Where I live in Montana, every neighbor around me has solar and batteries here. There are also neighborhoods that are talking about putting in community microgrids. It’s like a local little power system. One of the utilities in Vermont is talking about buying all of their customers generators because it’s more cost effective for them to do that and to build new electricity infrastructure. And so those transitions are happening underneath all this additional risk that I’ve been talking about.