High-voltage direct current [Wikipedia]:
A high-voltage, direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway)‏¹‏²‏³ uses direct current for the bulk transmission of electrical power, in contrast with the more common alternating current (AC) systems.‏⁴ For long-distance transmission, HVDC systems may be less expensive and have lower electrical losses. For underwater power cables, HVDC avoids the heavy currents required to charge and discharge the cable capacitance each cycle. For shorter distances, the higher cost of DC conversion equipment compared to an AC system may still be justified, due to other benefits of direct current links.

Most HVDC links use voltages between 100 kV and 800 kV. A 1,100 kV link in China was completed in 2019 over a distance of 3,300 km with a power of 12 GW. ‏⁵‏⁶ With this dimension, intercontinental connections become possible which could help to deal with the fluctuations of wind power and photovoltaics.