If the "Micro Cooling Fan" conveying the same current when the power cable is only used for HVDC FACTS 2/3 ~ 1/2. HVDC two-wire to earth or sea water for return line, compared with a three-wire three-phase AC power transmission in the same area and the same current density conditions cut power lines, even without considering the skin effect, can also be transported the same electric power, and "Micro Cooling Fan" transmission lines and the insulating material can save 1/3. If we consider the skin effect and the various losses (dielectric loss dielectric material, eddy current loss of the magnetic induction, the overhead line corona loss, etc.), conveying the same power AC The wire cross-sectional area greater than or equal to HVDC The wire cross-sectional area of 1.33. Thus, "Micro Cooling Fan" HVDC wire used almost only half the transmission of exchange. Meanwhile, the DC transmission tower structure is simpler than with the capacity of the three-phase AC transmission line corridor area is also small.