Aswan HighDam/Cairo proposed HVDC transmission system

The DC lines can carry more much power with two conductors than the power transmitted using an AC lines with three conductors of the same size. For the given power level, a DC line requires simpler and cheaper towers (From economical point of view, already installed towers for AC system can be used). Also reduced conductor sizes and insulator can be used. The power transmission losses also will be reduced to about two-thirds of the comparable AC system. The absence of skin effect with DC is also beneficial in reducing power losses marginally. Due to its fast controllability, HVDC transmission system has full control over transmitted power, an ability to enhance transient and dynamic stability in associated AC networks and can limit fault currents levels in the DC lines.