COLUMN // ENERGY
Scaling Up, Scaling Down
The way energy processes improve with scale will determine which technologies will thrive in different niches.
Written by Michael E. Webber
EXPERTS IN MULTIPLE FIELDS USE the phrase “energy transition” as a compact way to talk about the movement to simultaneously expand and decarbonize the energy system while operating in a warming world. Such a shift wouldn’t be easy even in the best of times, let alone when climate-related weather events are creating not only natural disasters but also political chaos, but the energy transition is already underway.
While the end state of the transition isn’t known, the way the energy system will evolve is definitely constrained. Not every option is equally possible. Instead, overlapping demographic, technology, and engineering trends put limits on the future of the energy transition.
Demographic trends change the amount, location, and purpose of our energy consumption. Any newly evolved system will need to contend with population growth, economic growth, urbanization, and industrialization.
Technology trends change the fuel and commercial solutions that will gain market traction. Energy systems need to embrace the increasing efficiency, growing information intensity, and the movement toward smaller, modular, decentralized options that the economy demands.
Those trends get a lot of attention from deep thinkers in other fields. The engineering trends are just as important, yet they don’t get as much consideration. But they should: An overarching trend around energy’s scaling laws from the last two centuries will enable and confine how the energy system evolves.
The most important energy engineering trends are 1) Thermal systems get economies of scale by sheer size; the bigger the better. And 2) Electrical systems get economies of scale by repetition; the more often they are made, the smaller and better they get. Innovations and evolutions over the last few decades affirm this notion that thermal systems scale up and electrical systems scale down.
For instance, nuclear power plants, steel mills, cement kilns, and glass factories all require or use heat as the key to their underlying processes. Over time, new plants become as big as economically possible to take advantage of the efficiencies that scale brings to their operations.
Take refineries, for example. These sprawling multibillion-dollar complexes use heat to separate out the various distillates from crude oil. In the United States, the number of refineries peaked at 324 in 1981. These were comparatively simple, small, inefficient and inflexible. Today, the U.S. has fewer than 150 refineries, but that doesn’t mean we as a nation have stepped back from the refining business. Far from it: Our remaining refineries are larger and more efficient than the ones from previous generations.
By scaling up, they have improved. The average capacity has gone up four-fold, they can accommodate more complicated forms of crude (think of the oil sands from Canada or the heavy oils from Venezuela), and they operate more cleanly than ever before.
By contrast, as the technology improves, electrical systems get smaller. Audio systems were once the size of furniture before reaching portability with boomboxes you could carry on your shoulder, the Sony Walkman you could carry on your hip, and the Apple iPod that would fit in your pocket. The development of the transistor—smaller, cheaper and higher performing than the vacuum tube—is just one example of the miniaturization at work with electronic devices. (Fun fact: one reason the U.S. led the early microelectronics industry was because our rockets were smaller than Russian rockets—we had to shrink the weight of electronics to lift them into orbit. The transistor in place of the vacuum tube helped accelerate that possibility.)
The same process happens with microprocessors, cameras, phones, computers, digital storage devices, you name it.
“Today, the U.S. has fewer than 150 refineries, but ... our remaining refineries are larger and more efficient than the ones from previous generations.”
These two engineering trends dictate what sorts of transition we’ll see, especially if electrical processes replace thermal ones or vice versa.
So, what happens when electrical processes displace thermal or mechanical processes? Electrochemistry in place of thermochemistry should improve efficiency, shrink footprint, reduce emissions, and lower costs. One reason is that electric motors are much easier to miniaturize compared to combustion engines and also much more efficient. That explains, in part, their market uptake for light-duty vehicles.
The history of electrolytic aluminum smelting provides a useful example. For most of the 19th century, aluminum was a semi-precious metal similar in price to silver. The Washington Monument was capped with an aluminum pyramid as an extravagant tribute to the invaluable and incorruptible character of the first president.
In 1886, Charles Hall and Paul Héroult independently invented an electrical process to replace traditional chemical, thermal, and mechanical processes for separating aluminum from bauxite. As a result, prices dropped swiftly from $4.86 per pound (more than $160 in today’s prices) in 1888 to $0.78 per pound in 1893. Today, aluminum—this once expensive metal—is so abundant and cheap people use it as a disposable wrapper for food in their kitchens, and no one would consider honoring a president with an aluminum tribute.
Can we replicate this transition at chemical facilities, refineries, and other industrial sites that use heat?
Switching to electro-smelting would make foundries smaller and replace dirty fuels like coal with cleaner electricity. Startup Boston Metal is doing this, deploying molten oxide electrolysis for steelmaking. (See “In Pursuit of Green Steel” in the January 2025 issue).
Would a switch to electro-refining or electrical fabrication of chemicals allow for smaller distributed systems that avoid sprawling infrastructure to convert flared gas into fuels, chemicals, or proteins on site, and make the bigger refineries unnecessary? Startups like Nitricity are already trying something similar, using “lightning in a bottle”: Electrically generated plasmas make fertilizers on the farm out of air, water, and plant waste, bypassing today’s centralized approach of manufacturing fertilizer via fossil fuels hundreds of miles from farms and piping or trucking it to where it’s needed.
In the end, electrifying more of society lets us harness the benefits of repetition, modularity, and scaling down, which will undoubtedly yield all sorts of unexpected innovations, cost savings, and cleanliness.
MICHAEL E. WEBBER is the Sid Richardson Chair in Public Affairs, John J. McKetta Centennial Energy Chair in Engineering, and engineering academic director of the KBH Energy Center at the University of Texas at Austin.
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