Superconductors can conduct electricity without any resistance or power loss and can effortlessly cause magnets to levitate above them. These properties would make superconductors useful for high-speed trains or long-distance power transmission in theory, but they only work at extreme low temperatures - more than one hundred degrees below zero.
This requirement makes building a hyper-efficient electrical grid or high-speed rail network very expensive. Researchers from the University of Houston, Adelwitz Technologiezentrum and the Leibniz Institute for Solid State and Materials Research believe that a network that accomplishes both tasks at the same time would be much more affordable.
Most magnetic-levitation (maglev) designs feature the superconductor inside the vehicle, which is itself suspended above a magnetic track. The authors decided to flip this arrangement upside-down, putting the superconductor on the ground and giving each vehicle a magnet. The result is a system with multiple uses, placing it within the realm of affordability.
Image credit: Vakaliuk et al
"Superconductor-levitated magnetic vehicles, instead of magnet-levitated superconducting vehicles, can provide additional benefits such as electrical power transmission and storage," said author Zhifeng Ren.
"We developed a new superconducting system that can transport and store a huge amount of energy and also transport people and goods with speeds of at least 400 miles per hour."
The team believes their design solves the problem of superconductor cooling with a liquid hydrogen pipeline.
While hydrogen is a promising clean fuel source, it is a gas at room temperature so transporting and storing it involves either dangerous pressurised tanks or costly cryogenic temperatures. In the team's proposal, the cost of cooling the superconductor and the cost of transporting hydrogen become the same.
Using a scale model in the lab, the researchers demonstrated that these applications can coexist. They now hope to build a full-scale demonstration. The authors envision their system would sit underneath existing highways to make use of current infrastructure.
"People can drive onto the superconducting highway any time without waiting for a train or airplane, and modifying the existing highways means there is no need to acquire land for the tracks," said Ren. "With enough financial support, we could make a working system over a relatively short distance, like from Houston to Austin [Texas, US]."
