The current wars that went on between Edison and Tesla a hundred years ago are still going on; people are still passionate about AC versus DC. When I first wrote about it, some of the more polite comments were like this one:
The main reason that everyone says that Alternating current is better is the issue of transporting electricity over distance. As my favorite commenter noted,
To the author of this article who thinks Tesla was WRONG. You are an idiot and KNOW NOTHING ABOUT THE GENERATION AND TRANSPORTATION OF ELECTRICITY! QUIT TELLING LIES!!!!!!!
The author is an idiot. Edison WAS NOT RIGHT. Thank you Tesla - The greatest genius inventor of all time. The transfer of DC voltages have limited ranges due to the resistance of the wires. If Edison had won, we would have ended up with coal fired power plants every two miles or so!!!!!
In Edison's time that may have been true; transformers only work with alternating current and Edison had no way to convert to high voltages needed for efficient transport. Now there is, and DC is actually better for long distances. According to the Economist:
DC distribution has, at least in principle, always had a lot going for it. Even now, at a sufficiently high voltage, it is cheaper than AC for transmitting large blocks of power over long distances. Not having to support three phases, as AC does, DC distribution requires fewer conductors.....Direct current also uses transmission cables more efficiently.
The real problem, according to the Economist, has been the circuit breakers: DC at high voltage is hard to turn off. Now, a new hybrid high voltage direct current breaker has been developed by ABB, who describes it breathlessly:
[ABB has] finally come up with a circuit breaker capable of blocking and breaking DC currents at thousands of amperes and several hundred thousands of volts - corresponding to the average power consumption of one million Europeans ! It amounts to stopping power capable of feeding a large city much faster than an eye blink ! This speed helps protect the DC transmission system and prevent power outages in new low loss compact power superhighways.
It is clear from all of this that transmission of electricity by high voltage direct current is cheaper, uses smaller wires, has lower line losses and is safer. The Guardian concludes:
That could lead both to cheaper power, and to the burial of many of the pylon-borne power lines that disfigure so much of the rich world's countryside. In a deeper, sense, then, perhaps Edison will have the last laugh, after all.
So can people stop calling me an idiot now?