Hybrid Energy Transfer Line With Liquid Hydrogen and Superconducting $\hbox {MgB}_{2}$ Cable—First Experimental Proof of Concept

The transfer of massive amounts of both electrical and chemical power over long distances will present a major challenge for the global energy enterprise in the future. Attraction of hydrogen is apparent as a chemical energy agent, possessing among the highest energy density content of various common fuels, whose combustive “waste” is simply water. It could be transferred via cryogenic tubes being liquid at temperatures ~18-26 K. The usage of “gratis” cold to cool a superconducting cable made of a proper superconductor permits to deliver extra electrical power with the same line. In this paper, we describe the experimental modeling of this concept via a combined MgB₂-cryogenic dc superconducting cable refrigerated by “singlet” phase liquid hydrogen. We present the design, construction details, and test results of a 10-m prototype, focusing on choice of MgB₂ cable and cryostat technologies. We also discuss the opportunities and possibilities for future practical deployment of such hybrid energy delivery systems.