Field notes The Energy Transition for the Rest of Us

Steel For Fuel N° 043 of 56 16 Jul 2025

On linemen, robots, hands, and brains

by Andy Lubershane, Partner and Head of Research, Energy Impact Partners

In this note
  1. 01The question
  2. 02The answer
  3. 03The argument
  4. 04What you need to know first
  5. 05Details worth keeping
  6. 06Claims worth citing
  7. 07Where it’s contested

The question

Can robots relieve the shortage of skilled manual workers, such as utility linemen, that is starting to constrain the energy transition?

The answer

Not soon. Lubershane is a robotics optimist, but he puts the jobs that need fine manual dexterity in messy environments several breakthroughs away, because human hands are extraordinarily hard to copy and human brains learn to use them on a tiny fraction of the energy and training data an AI model needs.

03The argument

The premise is quoted from his own earlier post: digital tools have made knowledge workers far more productive while labor productivity in the physical trades has stagnated, which he says puts it on track to become one of the biggest constraints on the global energy transition. A meeting the day before makes it concrete. Among about twenty-five utility executives responsible for transmission and distribution, one said his biggest problem was now finding linemen, having knocked on every door with no trained linemen left in his state. The framework, also carried over from that post, is a spectrum of robotic capability. At one end are discrete, repetitive, low-variability tasks that can be fully programmed and need no advanced AI at all. At the other are jobs in highly variable environments with more exceptions than rules, which also demand very fine object manipulation. His mental model there is a plumber, and linemen fall in the same category. That end is inconceivable without further AI advances; despite real progress in the field, autonomous vehicles among it, he puts robotic plumbers and linemen at least one giant leap away and says he personally believes several.

Why so far? Hands and brains. On hands he builds on a roboticist he quotes at the top: the space of words is bounded, the space of physical interaction is not. Even after collapsing each of the hand’s joints into a handful of discrete positions, the number of possible hand arrangements dwarfs the English vocabulary by an unimaginable margin, and that is before counting the hand’s touch receptors and its sense of its own position, which he declines to try to quantify.

On brains, two efficiency comparisons do the work and the second is the turn. Converting the food a child eats to adulthood into energy and taking the brain’s share, he puts the energy cost of training a human brain roughly four orders of magnitude below the reported energy cost of training a leading language model, while the child’s brain also learns bodies and emotions and acts throughout, doing training and inference at once. It is as frugal with data, learning language from roughly 150 million words where a model needs trillions. Then he extrapolates to hands, and that is where the answer comes from: even granting a robotic hand model the same data efficiency relative to a brain that a language model achieves, which he flags as extremely optimistic, training one would still take billions of hours. Hence humanoid robots have a long way to go, and he doubts they will beat purpose-built specialized robots within five years; the trades are the professions most insulated from AI in the labor market; and a young person unsure about desk work should consider becoming a lineman.

04What you need to know first

Lineman
The worker who climbs utility poles to install and maintain electrical equipment.
Training and inference
Training builds an AI model; inference runs the finished model to produce an answer or an action.

05Details worth keeping

  • The epigraph is Brad Porter, CEO and founder of Cobot, whom he calls a highly distinguished roboticist and whose former Amazon titles included vice president for robotics. The claim about bounded words and unbounded physical interaction is Porter’s.
  • The productivity passage and the capability spectrum are both carried over from his earlier post, “Ode to Physical AI”.
  • Two of the four figures are uncaptioned charts, but the text carries what they show, so no step of the argument depends on an image.

06Claims worth citing

All figures as stated on 2025-07-16. Several are his own back-of-envelope arithmetic on deliberately simplified assumptions.

  • Labor productivity in United States manufacturing and construction has been flat to declining for two decades. Lubershane, quoted from his own earlier post
  • The human hand has 27 joints; collapsing each into ten positions still yields 10^27 arrangements, against roughly 500,000 words in the Oxford English Dictionary and far fewer in regular use. Lubershane, with his colleague Anil Achyuta
  • The hand has about 17,000 touch receptors, roughly 40 per square centimeter. National Institutes of Health, cited by Lubershane
  • Raising a child to 21 takes roughly 15 million calories, about 20% of it to the brain, which he converts to about 3.5 megawatt-hours; training GPT-4 reportedly consumed about 50 gigawatt-hours, roughly 14,000 times as much. Lubershane, who marks the GPT-4 figure as reported
  • A child in a talkative household hears about 20,000 words a day, roughly 150 million by adulthood; leading models train on trillions. Lubershane
  • A child gets 184,000 hours of practice using their hands before 21. Lubershane

07Where it’s contested

Nobody argues back. What the post carries instead is a clear set of confidence markers and one undefended step.

  • The timing is hedged twice, at least one giant leap away and personally several; the humanoid skepticism is bounded to the next five years.
  • The key extrapolation is labelled optimistic by its author, which makes the billions-of-hours figure a floor rather than an estimate.
  • The load-bearing assumption is the analogy. That progress on hands should scale like progress on language is asserted, not defended.
  • The lineman shortage rests on one paraphrased executive at one meeting, and dexterity is treated as the binding constraint on automating the trades. Cost, capital and who would deploy such robots never come up.

Cite as: “On linemen, robots, hands, and brains,” The Energy Transition for the Rest of Us, note on Steel For Fuel, July 16, 2025. CC BY 4.0. View the Markdown