For the past two weeks, the alleged discovery by Korean scientists of the “holy grail” of physics — the first room temperature superconductor — has captured the world’s imagination. Superconductors transmit energy without any resistance. In science fiction, they are the key to unlocking countless energy breakthroughs, from nuclear fusion to levitating trains.
On social media, hopeful dilettantes, myself included, clicked refresh with rapt enthusiasm as professional and amateur scientists alike live-tweeted and live-streamed attempts to replicate the experiment and dissected the latest research. Overall sentiment about the findings oscillated dramatically from one hour to the next.
But now, the jig may be up. On Monday night, the Condensed Matter Theory Center at the University of Maryland reviewed the latest evidence and declared that LK-99, the material in question, was not a superconductor at all, much less one at room temperature. “With a great deal of sadness, we now believe that the game is over,” the research center tweeted.
There are many other labs investigating the research that have yet to weigh in, and the saga may not be over. There are also many other scientists tinkering away with other materials in hopes of making the same kind of discovery. But success might prove underwhelming. Because even if we soon identify a room temperature superconductor — whether LK-99 or another material — it’s unlikely to make tackling climate change any easier.
Pretty much every material we use to generate, move, and use electricity today has some amount of electrical resistance, causing the loss of energy in the form of heat. U.S. power lines, for example, lose about 5% of the electricity they carry. The main promise of superconductors, when it comes to climate change, is the potential to eliminate this shortcoming, improving the efficiency of everything from wind turbines to power lines to vehicles.
Scientists have already discovered superconducting materials, but the problem is that they only exhibit zero resistance when cooled to extremely low temperatures, like between -300 and -450 degrees Fahrenheit. That’s why a material that proves to be superconducting at room temperature would be so exciting — it could be much easier to use in commercial applications.
I asked Kiruba Sivasubramaniam Haran, an electrical engineer at the University of Illinois who studies applications for superconductors, what the most exciting potential use for such a material would be. “It’s hard to pinpoint because it’s going to impact everything,” he told me. “You can push the bounds of electric currents that you can push through a motor, you can push the bounds of magnetic fields, make everything really small and compact, and you can cut all the losses.”
Researchers aren’t waiting around for room temperature superconductors to try and do this. They are still attempting to exploit the last breakthrough in the field, in the late 1980s, when scientists discovered materials that were superconducting at slightly higher temperatures — closer to -300 than -400. That meant they could be cooled with liquid nitrogen, rather than liquid helium, which is a finite, expensive resource. The discovery was awarded Nobel prizes and set off an explosion of research.
Haran said that for pretty much every piece of equipment on the power grid, there’s already been a demonstration project to try and improve it with these so-called “high temperature superconductors.” The Department of Energy has supported projects testing them in grid equipment in Chicago, Long Island, and Columbus, Ohio. GE Research is working on putting them in wind turbines. Companies like Commonwealth Fusion Systems that are racing to develop fusion reactors — a potential source of limitless, clean energy — use superconducting magnets to control and confine plasma. Haran himself has a company that’s trying to use them to build lightweight electric motors capable of powering large airplanes.
It’s been decades and these applications have yet to scale. Part of the challenge, Inna Vishik, a materials scientist at the University of California, Davis, told me, is achieving cost parity with existing solutions. Take transmission lines, which today use copper wire. Copper may not be perfect, but it’s cheap, and it’s already there. “I don't think we'll ever discover a superconductor that's cheaper than copper,” she said.
It’s true that part of what has held superconductors back has been the need to cool them. Karan said that his company is close to breaking even with its electric motor, and that a superconductor that could withstand higher temperatures would turn the trade-offs in its favor.
But other scientists stressed to me that temperature is just one factor. Jonathan Menard, chief research officer at the Princeton Plasma Physics Laboratory, told me that one of the bottlenecks for fusion has been manufacturing superconductors at scale. “The industry is challenged to figure out how to build this material in bulk and meet quality requirements that the fusion companies want,” he said.
The utility of a room temperature superconductor will also depend entirely on other properties of that material, such as how much current it can carry while remaining superconducting. We could very well discover a room temperature superconductor that’s entirely useless for many applications.
“All of the different superconducting materials have different critical properties,” said Menard. “They only stay superconducting below a certain magnetic field, below a certain temperature, and under certain stress conditions. We really have to assess it for all of those limits.”
Not to overly moralize the story of LK-99, but it’s dangerous to fall prey to magical thinking. There are no quick, easy solutions to climate change, but there are solutions that exist today. Holding out for technological breakthroughs risks failing to take advantage of all the opportunities to cut emissions at our fingertips.
Climate change is a problem of accumulation, and every ton of carbon that goes into the atmosphere matters. If scientists found a game-changing superconductor tomorrow, the world would face far fewer hazards by cutting emissions as rapidly as possible than if it waited for the discovery to translate to commercial applications.
There’s a glass-half-full version of this: Room temperature superconductors would be a monumental discovery, but we certainly don’t need them to decarbonize.
GMC