Scientists develop energy-efficient superconducting cable

Scientists from the Karlsruhe Institute of Technology (KIT) have developed a superconducting cable that can transport electrical energy with hardly any losses.

The High-temperature Superconductor Cross Conductor (HTS CroCo) may be used to integrate large wind parks or solar power plants into the grid and to design leaner ‘electricity highways’ in the future.

Superconductors transport electrical current at low temperatures with almost no losses, which makes them attractive for a number of energy-efficient technologies, but they often require cooling with liquid helium to a temperature near minus 269°C. The HTS CroCo is based on rare-earth barium-copper oxide (REBCO) material, which means it can be used at minus 196°C.

However, long lengths of the superconductor can only be manufactured in the form of thin tapes.

“We have developed a method where several REBCO tapes are arranged such that they form a cross,” explained Dr Walter Fietz of KIT’s Institute for Technical Physics (ITEP).

As well as having a higher current-carrying capacity, the cable also requires less space and has a lower weight compared to conventional copper or aluminum cables. According to the researchers, CroCo is suitable for energy-efficient generation of high magnetic fields and for transporting large amounts of electric energy. If liquid hydrogen is used for cooling, it can transport chemical and electrical energy together.

“In principle, a CroCo can be applied wherever space is limited, but the amount of electrical energy to be transported is high,” Fietz said.

Future applications could include connecting wind parks, for DC supply on ships, or for lightweight and compact high-current cabling in electric airplanes.

Dr Michael Wolf of KIT’s ITEP noted mass production is prevented by the high costs for the complex manufacture of REBCO tapes, but industry is developing new processes to reduce costs.

Image credit: © ITEP, KIT.