AC vs DC
the current wars one last time
AC vs DC
Thomas Edison and Nikolai Tesla famously fought their “current wars” in the late 19th century. Edison used “one-directional” direct current (DC) for the distribution of electricity, and Tesla used a “back and forth” alternating current (AC) approach. Tesla won the battle because AC could be distributed over long distances whereas DC lost its power after about a mile of distribution. DC was less useful to move electricity from fossil-fuel based power plants into remote areas.
More than a century later, innovation is proving Edison was right after all. Clean, renewable energy based microgrids are the “local power stations” Edison foresaw in his time.
Today, microgrids located in neighborhoods make it possible to attain the many advantages of direct current: Solar, wind, and geothermal power are rapidly becoming the leading sources for energy production. Each of these power sources natively generates DC.
DC power distribution is more energy efficient. There is no energy loss over long-distance transmission lines.
All electronic equipment operates on DC power.
Large motors as well as personal computers and cell phones use the one-directional flow of the electrons. Thus, transformers are used to convert the AC from the power socket into DC for electronic equipment. This transformation of electricity current causes energy losses. Electronic equipment using DC directly saves about 25 percent energy compared to same equipment running on transformed AC.
Most energy storage systems like batteries are DC-based. Unlike AC, DC can produce the exact amount of energy the consumer needs. This makes DC-based microgrids much more efficient than the current long-distance transmission networks.
The maintenance of DC microgrids is much cheaper than maintaining the heavy infrastructure of AC from power stations to long-distance cables.