Direct Current Electricity Transmission

Until very recently, electrical transmission over long distances via direct current (DC) was not efficient.  Technological innovations have now made transmission via DC more efficient than alternating current (AC).  Since much of the electrical demand is from equipment and devices that natively operate on DC power, additional efficiency can be gained if the conversion step from AC to DC is removed.

Link: http://www.resilience.org/stories/2016-05-03/slow-electricity-the-return-of-dc-power