[johnjac]

Yeah, this should have been included in the article. From Wikipedia: A long distance point to point HVDC transmission scheme generally has lower overall investment cost and lower losses than an equivalent AC transmission scheme. HVDC conversion equipment at the terminal stations is costly, but the total DC transmission line costs over long distances are lower than AC line of the same distance. HVDC requires less conductor per unit distance than an AC line, as there is no need to support three phases and there is no skin effect. https://en.wikipedia.org/wiki/High-voltage_direct_current#Ad...