Hydrogen cooled superconductors are an existing technology that could be used in the construction of a new national energy grid in densely populated corridors. Carbon-free energy generation of wind and solar producing storable hydrogen gas through electrolysis of sea-water would far surpass battery technology in producing energy for latter use.

Pipelines full if liquid hydrogen cooling fairly high-temperature superconducting would accomplish two important energy purposes simultaneously; providing hydrogen gas that can be used directly for energy production as it is quite explosive and comparable to gasoline or propane, and enabling superconducting power lines that can store electricity themselves with no transmission loss (zero resistance). In turn, the existence of a zero-resistance power line will allow solar and wind power to store energy in that too, creating a triple advantage over existing technology of the energy infrastructure.

https://www.bloomberg.com/news/articles/2017-09-05/better-than-a-battery-big-energy-backs-hydrogen-power-storage

https://phe.rockefeller.edu/docs/SA_Supergrid.pdf Hydrogen-filled super-grid

http://large.stanford.edu/courses/2010/ph240/yankowitz1/  Superconducting Power Transmission

Paul M. Grant, Chauncey Starr and Thomas J. Overbye

Scientific American

Vol. 295, No. 1 (JULY 2006), pp. 76-83  http://palgrave.nature.com/scientificamerican/journal/v295/n1/box/scientificamerican0706-76_BX3.html