Substations are getting walls because chain-link stopped being enough. In December 2022, gunfire at two substations in Moore County, North Carolina left 45,000 people without power for up to five days. In 2024, a Columbia, Tennessee man was arrested for plotting to fly an explosive-laden drone into a substation near Nashville. Regulators are tightening the physical security rules, and TVA expects data center load in our region to double by 2030. More critical equipment, more attention, and a fence you can see (and shoot) straight through.
If you live around Sparta or Cookeville, you’ve driven past a dozen substations this month without thinking about them. Here’s why the people who own them are thinking about them a lot.
Moore County and Metcalf showed how cheap an attack can be
You don’t need a sophisticated plan to take a substation offline. You need a rifle and a clear line of sight.
The case that set today’s rules is Metcalf. In 2013, attackers took down 17 transformers at Pacific Gas & Electric’s Metcalf Transmission Substation near San Jose, and as Marketplace reported a decade later, no one was ever arrested. The same report notes that the substation is now “fortified with walls and cameras.”
Then came Moore County. On December 3, 2022, attackers fired on two substations, and the outage hit 45,000 people, some of them for five days. Twelve days later, the Federal Energy Regulatory Commission ordered the North American Electric Reliability Corporation (NERC) to study whether its physical security standard was actually working. That order cited Moore County by name, along with a string of November 2022 incidents at substations in the Pacific Northwest.
The Nashville drone plot made it a Tennessee story
It’s easy to read about North Carolina and California and file it under “somewhere else.” Well, the truth is that one of these plots was aimed at a substation less than two hours west of Sparta.
In November 2024, federal agents arrested Skyler Philippi, a 24-year-old from Columbia, Tennessee, for attempting to use a weapon of mass destruction against a Nashville electric substation. His plan was to attach explosives to a drone and fly it into the station. Agents working undercover had driven with him to scout the site. He pleaded guilty in September 2025, according to the Justice Department.
That plot never got off the ground, and it was an FBI sting, not a wall, that stopped it. But it answers the question you might actually be asking: does anyone target Middle Tennessee’s grid? Yes. Somebody already tried.
What CIP-014 requires, and what changes in 2028
CIP-014 is the federal reliability standard for the physical security of the transmission stations and substations whose loss would do the most damage to the bulk power grid. FERC approved the first version in November 2014, after Metcalf.
According to FERC’s order approving CIP-014-4, published in the Federal Register in September, the standard works like this:
- The transmission owner runs a risk assessment to find which of its stations are critical.
- It evaluates the threats and vulnerabilities of a physical attack on each of them.
- It writes and carries out a documented physical security plan.
- An unaffiliated third party reviews the evaluation and the plan.
FERC approved version 4 on September 10, 2026, and it takes effect October 1, 2028. The big addition is a neighbor rule: owners have to identify other transmission stations and substations within 1,500 feet of a critical one, measured fence line to fence line, no matter who owns them. The logic is obvious once you say it out loud. Two stations that sit side by side can be hit in one trip.
Here’s the honest limit. CIP-014 doesn’t tell anybody to build a wall. It tells them to assess the risk and write a plan. A wall is one answer a lot of those plans are landing on.
Why a fence you can see through is the weak spot
A chain-link fence with barbed wire does one job well. It keeps people from walking in. Moore County and Metcalf weren’t walk-in attacks. They were gunfire from outside the fence, aimed at equipment the attackers could see.
That’s the case for a solid wall, and it’s my read rather than a rule: block the view and you take away the aiming point. Harden the wall and a round that does get fired has to go through concrete first. That’s why “walls and cameras” is how Metcalf ended up.
You’ll also notice that these walls don’t have to look like a prison yard. Precast manufacturers now sell electrical substation walls as factory-made panels with stone and brick finishes, because a lot of new substations sit right next to neighborhoods. Permacast, a Florida precast company, says its panels are engineered to the UL 752 bullet-resistance standard. It’s worth knowing the category exists before your county planning board sees its first site plan with one on it.
Data centers are putting more substations on the map in TVA country
This is where it comes back home. Data Center Dynamics reported in February that data centers made up 18 percent of TVA’s industrial load in 2025, and TVA CEO Don Moul said he expects data center load “to double in our region by 2030.”
Think Tennessee’s July report, Powering the Boom, found that data center electricity use in the Tennessee Valley grew sevenfold between 2020 and 2025, to 8.3 million MWh.
Every one of those facilities connects to the grid through a substation, and that’s more equipment worth protecting.
What this means if you live or run a business here
You don’t have to become a grid-security expert. But you can actually do a few useful things:
- Report anything odd at a substation (people photographing the fence line, a drone hovering over the yard, a cut lock) to the utility and to law enforcement.
- When a data center or a big new substation shows up on a planning agenda, ask what the security and screening plan is. A solid wall is quieter to look at than razor wire, too.
- If you run a small business, cheaper power and a steadier supply start with what you control. Our guide to funding green energy for Tennessee small businesses covers the TVA and USDA programs.
So the next time you pass a substation on the way into Sparta, look at what’s around it. Is it chain-link, or is it a wall? And if a data center lands in White County, which of those do you want its substation to have?
More on energy, data centers and the community in our green energy community blog.