SuperGrid
In lossless power transmission, a supergrid with hydrogen is an idea for combining very long distance electric power transmission with liquid hydrogen distribution, to achieve superconductivity in the power lines. The hydrogen is both a distributed fuel and a cryogenic coolant for the power lines, rendering them superconducting. The concept's advocates describe it as being in a "visionary" stage, for which no new scientific breakthrough is required but which requires major technological innovations before it could progress to a practical system. A system for the United States is projected to require "several decades" before it could be fully implemented.