Arab Construction World Article on Elpipes in the MENA (Middle East & Northern Africa)

I wrote an article for the July issue of Arab Construction World:
Underground Multi-Terminal HVDC Power Supergrid in the MENA
In this article, I compare copper, aluminum, and sodium conductors as to volume, mass, and cost per meter for equal diameter elpipes to move 6250 amps 1000 km, with a loss of 0.5% of transmitted power for each polarity. Because two such elpipes are required to move the power out and back, this corresponds to 1% resistive power dissipation over 1000 km for an 800kV line (800kV line at 6250 amps → 10 GW line, about the right size for an initial multi-terminal HVDC project):

Notice that even though more than twice as much volume of sodium is required compared to aluminum to achieve equal conductivity per meter, that volume of sodium weighs 10% less than the equivalent conductivity volume of aluminum, and costs nearly a factor of five less than the aluminum. Aluminum is in turn ten times less expensive than copper.

I would not recommend installation of sodium based conductors in populated regions, but as long as sodium is deployed inside high-melting metal shells that also contain expansion compensation bladders (as described in the PCT Patent Application on elpipes), a sodium-based elpipe can be as safe as other pipelines we routinely accept as a cost of our modern lifestyles  Certainly, the first implementations of elpipes should be based on aluminum, though.