22-05-2025
How AI And A Stiff Breeze Vitalize Our Aging Grid
A worker installing a LineVision DLR sensor on a sub-transmission tower
After decades of flat to declining electrical utility demand, customers are suddenly clamoring for more power. AI data centers have driven that demand, but home electrification and EVs have also boosted the electric load on our aging grid.
Utilities' present infrastructures are based on 10-year-old plans that didn't foresee this surge in demand. Building new power plants or stringing miles of new transmission lines doesn't happen overnight, so utilities are scrambling to do more with less.
Boston start-up LineVision and several European competitors are leveraging a new technology called dynamic line ratings to help utilities do more with less. DLR systems allow grid operators to increase the current flowing through high-voltage transmission lines like the ones pictured below.
A transmission line in Waikanae, north of Wellington, New Zealand.
The difference between current and voltage can be visualized by a conveyor belt carrying boxes of a uniform size. The fixed box size represents voltage, while the speed of the conveyor belt represents current. To deliver more boxes in the same amount of time, you increase the speed of the conveyor belt.
The same is true for electrical generation. Generation facilities respond to increased demand by producing more power and sending it through transmission wires at a constant voltage, but higher current.
If electrical grids were conveyor belts, it would be easy to just boost the amperage (another word for current, which is measured in amperes) flowing through the lines. However, as current increases, transmission lines heat up and sag due to thermal expansion. Sagging places a strain on transmission towers and, if severe enough, might cause lines to brush against vegetation, sparking fires (read my article PG&E: The First S&P 500 Climate Change Casualty). The sun's heat causes lines to sag more on sunny days, while increased airflow on windy days cools the lines, which sag less.
Industry conservatism and the threat of wildfire-related lawsuits prompt grid operators to keep transmission currents low to prevent excessive line sagging. This conservatism is warranted on hot, still summer days when everyone is cranking up their air conditioning, but such caution often restricts the amount of electricity available to customers.
DLR systems signal grid operators to throttle back on the current on sunny, still days and crank up the current when demand spikes on cool, cloudy, windy days.
A solar powered DLR device from LineVision installed on a transmission tower
Such slight adjustments might seem trivial, but DLR systems enable amazing capacity increases. A brisk wind allows 50-100%+ amperage increases over static assumptions on a case-by-case basis, leading to average grid-wide capacity increases of around 40%. Replicating such increases over the entire 700,000-mile grid network could result in enormous economic benefits.
Increased 'ampacity' (i.e., current capacity) reduces the demand for new generation facilities and transmission lines, clears transmission bottlenecks, increases the grid's capacity for cheap renewable energy, and helps grids re-energize faster after equipment failures.
The pioneer of DLR systems is Ampacimon, a Belgian company spun out of a university in 2010. Its devices are installed directly onto transmission lines, deriving power from the lines' electromagnetic field. The devices sense determinants such as wind vibrations and the lines' temperature, then use theoretical models to infer from measured inputs and local weather reports how much sagging is likely to occur, which they report to the grid operator in real-time via cellular links.
Heimdall Power, a Norwegian company founded in 2016, applied a twist to Ampacimon's model. Heimdall's devices are installed onto transmission lines via drone and operate on harvested electric power. However, rather than using theoretical models, Heimdall's devices are equipped with MEMS chips and accelerometers, the sensors in your phone which measure movement and relative position to the earth. The devices infer from this location data the sag across the span to which they are attached. You can learn more about Heimdall's solution here.
Ampacimon's devices originally required that power to the lines be shut off for installation, but now both they and Heimdall's devices can be installed on live transmission wires, making installation less disruptive.
LineVision is the only DLR company to implement direct sag and temperature measurements using LIDAR, electromagnetic field sensors, and AI-powered visual imaging. LineVision sensors attach to towers rather than the lines themselves and are powered by solar cells and batteries, enabling the system to estimate line capacity when a grid goes down and is attempting to restart. Sensor installation is quicker and easier on towers than on lines, cutting capital costs.
LineVision's software uses AI to monitor line conditions and integrates local weather forecasts to predict future line conditions, then conveys capacity recommendations to grid operators.
National Grid, a U.K.-based utility with operations in the U.K. and New York State, estimated that LineVision's DLR has generated over £1 billion in transmission grid congestion reductions and upgrade deferrals.
We are putting an enormous burden on our aging grid, which is comprised in many regions of lines older than 30 years on average. I believe that power generation and distribution in the post-Climate world will require a complete rethink of the Industrial Revolution paradigm by which we built our present grid, but even a modern, distributed grid will need a strong, efficient transmission network. Dynamic line ratings, powered by modern sensors, AI and an occasional stiff breeze, are a critical advantage. Intelligent investors take note.
