There is an unprecedented boom of construction for electric transmission lines. These are the giant towers that are used to carry electricity for long distances. The boom was kick-started in the last few years as transmission lines have been built to support solar farms, wind farms, and some new nuclear power plants.
But the boom went into overdrive by the sudden explosion of new data centers being created to support AI. The International Energy Agency predicts that in the U.S. that the growth of data centers will consume 6% of all electricity generated in the country by 2026, up from 4% in 2022.
This boom is perhaps the most obvious in Northern Virginia, which is the hub of the worldwide Internet, and where Culpepper County has approved construction of 12 million square feet of new data centers. These new data centers will use 2.5 gigawatts of power, more than 10 times what the County is using for everything else today. Many of these new data centers come with new power generation facilities. The boom in data centers will also require building new transmission power lines to bring power in from neighboring areas.
In Northern Virginia, PJM Interconnection, the regional grid operator in the mid-Atlantic, is moving forward with a number of transmission line projects to address the burst of power demand. The company is working on two large transmission line projects, at a cost of $4.9 billion that will be able to handle 7.5 gigawatts of power. PJM and Dominion Electric are considering extra transmission lines for Culpepper and surrounding counties.
Transmission line projects are controversial, and the PJM proposed projects cross through conservation lands such as the newly formed Sweet Run State Park in Loudoun County, Harpers Ferry National Historic Park, the Appalachian Trail, Waterford Historic District, Manassas National Battlefield Park, numerous local parks, wetlands, and privately held conservation easements. The giant towers are considered by many to be an eyesore, but the bigger problem is that the rights of way beneath the giant towers are typically treated repeatedly with herbicides to keep the areas open.
The new transmission lines are a natural place to hang fiber optic cables, which can be manufactured to be electrically neutral and non-conducting. I’m aware of several transmission projects where the builders are adding fiber and hoping for a second revenue stream by selling fiber transport.
There are some issues involved with placing fiber on transmission lines. Many of the proposed transmission lines don’t go to places where there is a demand for fiber. This could be fixed by building additional fiber at the ends of the transmission routes to extend fiber to meet existing long-haul fiber routes.
From an operational perspective, there are major issues for technicians working near these lines because of the extremely high voltages. Most transmission lines carry between 150,000 and 750,000 volts, and only highly trained technicians are allowed to work near the lines. Safety practices forbid technicians from working within 20 feet of a transmission line carrying up to 350,000 volts and within 50 feet for lines carrying more than that. That’s a problem when needing to make fiber repairs, since it would normally mean shutting down electric power to make the repairs. The most useful place to place fiber from a telecom perspective would be below the power lines, where technicians could always get access, but many grid operators prefer fiber to be at the top of the tower so as to not interfere with work being done by power technicians. A middle ground is to put fiber at the top and establish access points at the bottom of a tower.
Since there are transmission lines being built with fiber, we’ll have to wait and see in practice how attractive the fiber routes are to broadband companies. There will be a huge number of miles of transmission lines built over the next decade, and it would be a shame if we can’t figure out a practical way for this to benefit our middle-mile and long-haul fiber networks.