Where have all the transmission lines gone?
Chart(s) of the week
Here’s a real bummer of a chart, which comes from Grid Strategies, one of the sharpest groups you’ll find working on electric transmission issues, today.
Notes:
This is probably the #1 most concerning trend for the pace of the energy transition in the US. In short: transmission is the foundation of the power grid; and bigger, longer lines have become increasingly critical for unlocking renewable energy resources. We need to be speeding up deployment of that kind of line, not slowing down.
Given that new high voltage transmission development has stalled out, I’m increasingly confident that we will need to lean on technology designed make better use of the lines we already have. There are a myriad of tools which offer a higher degree of sensing, monitoring, and control over the flow of electricity on the grid. Back in the day, these sorts of tools were often classified as “smart grid technology”; but these days, all the cool kids seem to be using the term “Grid Enhancing Technologies”, or “GETS”. Whatever you call them, I’m a big fan of solutions that can squeeze more juice out of existing transmission corridors.
For example, companies like LineVision, Prisma Photonics, and Ampacimon have each developed distinctive approaches to a strategy referred to as “Dynamic Line Rating”, or DLR. Currently, the vast majority of transmission lines are given a static capacity rating, which is limited by the risk of the most adverse conditions a line might experience in a given season (or, in some cases, ever), such as the confluence of especially high temperatures and wind speeds. By contrast, DLR permits grid operators to continuously adjust the rating of each line based on real world operating conditions. Most of the time, this dynamic approach translates to a higher capacity rating, which permits higher throughput.
For example, here are the results of a recent study on a pilot run by the transmission operator AES, using LineVision’s kit. DLR managed to increase the average summer capacity of the highest voltage line by over 25%.
“Lessons from first deployment of Dynamid Line Ratings”, AES & LineVision, April 2024. A case study of 42 LineVision sensors on 5 AES transmission lines. On the other hand, implementing DLR and other “GETS” in the real world requires navigating a thicket of deeply technical issues interpersed with regulatory thorns. The same goes for swapping out conventional wires for advanced conductor materials, some of which I find really promising (such as TS Conductor’s composite core solution). Keep in mind: These are both areas in which it’s easy for those of us who are not actually responsible for operating the grid to become enamored with elegant-sounding solutions… which can run into lots of nitty gritty technical complications in practice. So, while I continue to be hopeful about new technology in this space, I stand by my conclusion over a year ago that “transmission expansion is still, ultimately, more of a collective action problem for governments & citizens than it is a puzzle for technologists.”
On that note: The Grid Strategies team points out that FERC and the DOE have been taking a number of actions (within their statutory authority) to try to remove obstacles to transmission expansion.1 I’m cautiously optimistic about some of this recent activity, particularly FERC Order 1977, in which the agency further asserts and outlines its backstop siting authority in a small number of designated National Interest Electric Transmission Corridors. Still, I believe that more comprehensive permitting reform is almost certainly needed to get the job done. Senators Joe Manchin and John Barraso have proposed bipartisan legislation, the Energy Permitting Reform Act which would expand FERC’s backstop authority to any transmission corridor “in the national interest”. Steel for Fuel readers here in the US might want to consider calling their congressperson…
FERC = Federal Energy Regulatory Commission (US). DOE = Department of Energy (US)