Nostalgia & History > Con Ed Finally Ends DC Service

Off topic but likely of interest to many of us:

NY Times November 14, 2007
Off Goes the Power Current Started by Thomas Edison

By Jennifer 8. Lee

Today (11/14/07), 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 phase 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.”)

But direct current clearly became uneconomical, as the short distances that it could be transmitted would have required a power station every mile or less, according to Joe Cunningham, an engineering historian. Thus alternating current in New York began in the outskirts — Queens, Bronx, Upper Manhattan and the suburbs.

The direct current conversion in Lower Manhattan started in 1928, and an engineer then predicted that it would take 45 years, according to Mr. Cunningham. “An optimistic prediction since we still have it now,” he said.

The man who is cutting the link today at 10 East 40th Street is Fred Simms, a 52-year veteran of the company. Why him?
“He’s our closest link to Thomas Edison,” joked Bob McGee, a Con Ed spokesman.


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A previous article in the NY Times explained Con Ed's intent and expectation to end DC by the end of 2005:

Fade to Black

By JIM RASENBERGER

Published: January 2, 2005

Under the streets of New York, amid the maze of copper mains and transformers that compose the city's power grid, an ember of Manhattan's past will soon fade into darkness. Con Edison has announced that it aims to shut off direct current electricity, also known as DC, by the end of this year. If all goes according to plan, the only electricity provided by the utility after next December will be alternating current, known as AC.

The significance of this may be lost on many New Yorkers. Just as long as the coffee maker switches on in the morning and the refrigerator keeps humming, who really cares whether the current behind it is direct or alternating?

But if the demise of direct current doesn't quite rise to the poignancy of, say, the Dodgers' farewell to Brooklyn, it's still a swan song worth playing. To the dwindling number of New Yorkers who continue to use the old current, it's a matter of serious practical and financial consequence. For everyone else, it's an opportunity to revisit a pivotal moment in the dimly lit past of the original electric city.

The story of direct current begins in Lower Manhattan, at 255-57 Pearl Street. Today, the address lies under a parking lot, but 123 years ago it was the site of Thomas Edison's first electric power plant.

(snip history lesson about electric power and the great AC / DC wars)

IN the end, Edison's attempts to tarnish AC proved fruitless. AC was simply too economical, too sensible, to be checked. Indeed, given all of AC's advantages, it is remarkable that DC continued to endure in New York's power grid all these years.

Today, about 1,600 customers still receive DC power in New York. All are in Manhattan, scattered among Upper West Side apartment houses, Garment District loft buildings, hotels and brownstones. Typically, these users rely on DC for limited purposes, like feeding the motors of century-old elevators or fire pumps, relics from an earlier age of electricity. The holdouts have withstood a five-year campaign by Con Edison to wean them from DC, including cajoling letters and escalating surcharges. Con Ed's patience is wearing thin.

"I have a drop-dead date," said Stephen F. Wood, the utility's vice president of energy services and point man on DC elimination. "The president of the company has basically said: 'You've committed to getting this out of the system by the end of 2005. Now make it happen.' "

According to Mr. Wood, Con Edison's incentive to provide direct current ended when the utility shut its last DC power plant 20 years ago. Since then, Con Ed has been converting AC to DC by way of hundreds of underground rectifiers. Maintaining two separate power systems, one quite old, is cumbersome, and, Mr. Wood added, "DC gives us a higher percentage of problems per section of cable than we get from the AC system."

Whatever the solution, it's unclear how many of the 1,600 will comply with Con Ed's deadline. "We know we'll have some customers, a limited number, who are going to be very difficult," Mr. Wood allowed. "Probably a couple hundred who are going to hold out to the bitter end."

DC is not altogether doomed for extinction in New York. The subway has run on DC since it first began operating a century ago and will continue to do so. But as a public utility, after almost 123 years of faithful service, give or take the occasional blackout, DC is quietly taking its last rounds before the lights go out.