Off the grid in NYC
Tesla finally wins!!!
Consolidated Edison pulled the plug on its last Direct Current customers today. From
SFGate:
NYC Pulls Plug on Direct Current
The city that Thomas Edison electrified 125 years ago has completed the transition from direct to alternating current, helping to erase the vestiges of a feud between giants of invention.
The Consolidated Edison utility on Wednesday pulled the plug on direct current service with electric operations manager Fred Simms, a Con Ed employee for 52 years, cutting a ceremonial cable on a Manhattan street.
The change means that Con Ed now exclusively uses the alternating current system invented by Nikola Tesla. The utility is named for Edison, whose Pearl Street Station in Manhattan was the nation's first central electrical power plant, serving 59 customers with direct current beginning in 1882.
In the so-called "war of currents," Edison feuded with Tesla and George Westinghouse over which transmission method to adopt � even going so far as to publicly electrocute animals in the hopes of showing AC was too dangerous.
Alternating current proved superior as transformers allowed electricity to travel over long-distance wires. As AC gained prevalence over DC worldwide, Con Ed froze the development of the DC system in 1928 but continued to supply New York's major DC customers with the existing system.
In January 1998, Con Ed began to eliminate DC service. At that time, there were more than 4,600 DC customers. By last year, there were only 60.
Back then, DC was superior for Theater Arc Lights and some motor applications (elevators) because of the smoothness. This was before Power Electronics came into widespread use.
In the 1970's I was living in a loft in a warehouse and that building was supplied with DC as well as the standard AC utilities.
It is a bit ironic that today, there are some major DC power transmission lines -- when you stay at one voltage all the time instead of zooming up, sliding down through zero and zooming down and back again, you can pack more
Coulombs into your conductor. Modern power electronics are able to change from AC to DC and back again with high (over 95% efficiency).
The
New York Times also has a bit on the story:
Off Goes the Power Current Started by Thomas Edison
Today, Con Edison will end 125 years of direct current electricity service that began when Thomas Edison opened his Pearl Street power station on Sept. 4, 1882. Con Ed will now only provide alternating current, in a final, vestigial triumph by Nikola Tesla and George Westinghouse, Mr. Edison�s rivals who were the main proponents of alternating current in the AC/DC debates of the turn of the 20th century.
The last snip of Con Ed�s direct current system will take place at 10 East 40th Street, near the Mid-Manhattan Library. That building, like the thousands of other direct current users that have been transitioned over the last several years, now has a converter installed on the premises that can take alternating electricity from the Con Ed power grid and adapt it on premises. Until now, Con Edison had been converting alternating to direct current for the customers who needed it � old buildings on the Upper East Side and Upper West Side that used direct current for their elevators for example. The subway, which has its own converters, also provides direct current through its third rail, in large part because direct current electricity was the dominant system in New York City when the subway first developed out of the early trolley cars.
Despite the clear advantage of alternating current � it can be transmitted long distances far more economically than direct current � direct current has taken decades to faze out of Manhattan because the early backbone of New York�s electricity grid was built by Mr. Edison�s company, which had a running head start in the first decade before Mr. Tesla and Mr. Westinghouse demonstrated the potential of alternating current with the Niagara Falls power project. (Among the customers of Thomas Edison�s Pearl Street power plant on that first day was The New York Times, which observed that to turn on its lights in the building, �no matches were needed.�)
Tesla was flamboyant and very much a showman but you need to remember, that he was a genius Electrical Engineer first and foremost. After all,
Tesla invented Radio...
Posted by DaveH at November 14, 2007 9:21 PM