Last DC power in NYC to shut down
Con Edison is shutting down the last direct current power in Manhattan, currently serving 10 East 40th Street, near midtown. Thomas Edison was a DC maniac and a fanatical opponent of Tesla's alternating current (he used to shock livestock to death with AC power, just to prove how bad it was -- he eventually worked his way up to an elephant!).
Link (via Kottke)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.”)
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.
(Image credit: IMG_5766 (Edison from the National Portrait Gallery), a CC-BY photo from dbking's Flickr stream)
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Yay, Tesla wins! Now someone has to figure out how to build his antenna to harness the energy of the sun:
http://www.pbs.org/tesla/ll/ll_todre.html
What was the direct current being used for? Apparently elevators and sprinkler systems, but those buildings must have had AC for everything else, most stuff needs AC these days, other than straightforward incandescent lighting.
DC power has clear advantages that the laptop set does not seem to realize. You make it sound like it is universally obsolete. If you live off the grid or want a self sufficient life, you need to embrace DC.
read here:
http://www.infoworld.com/article/06/10/06/41FEgreendc_1.html
and here:
http://www.treehugger.com/files/2007/09/big_steps_in_bu_3.php
DC power is still used for transmission over long distance as contrary to the urban myth DC has lower transmission losses at high voltages. The problem comes in tranforming down to lower voltages which is difficult for DC, but easy for AC.
Just think what life would be like today if Edison had been able to get Congress to pass an Electric Millenium Control Act, declaring use of AC power to be felony interference with a business model.
The "Cook Strait Cable" in New Zealand is DC.
I think another, perhaps the main, reason why DC is used for long distance transmission is to avoid the lines becoming a giant antenna. If my math is right, the wavelength of 50 Hz is 6000 Km. The behaviour of a transmission dramatically changes if its length gets close to a 1/4 wavelength.
Con Ed may be shutting down the last of Con Ed's DC service, but almost all of NYC subway trains are powered by 600 VDC on that third rail. Newer subway cars have AC motors and loud converters to convert the 3rd rail DC into AC. That's the sound you hear when those newer trains pull in and out of stations. A quote from nycsubway.org: "Alternating current (AC) operates signals, station and tunnel lighting, ventilation and miscellaneous line equipment. Direct current (DC) is used to operate trains and such auxiliary equipment as water pumps and emergency lighting."
If Edison had had his way, our current problem of cheaply and efficiently integrating clean and renewable energy sources into the grid would be far easier. Despite Tesla's extreme coolness, and Edison's over-inflated reputation, Edison was right on this one.
I just find it great that 40th street between 5th and 6th is called Nikolai Tesla Way in NYC...
I was on the coop board of my old building, and one of the issues that came up was the expected shutoff of the incoming DC line. We had been using DC for the elevators.
Con Ed had an offer, where they would basically pay for an AC-to-DC converter to be installed, as well as for a technician to do the site survey, installation, etc.
So, yes, DC mains are now defunct, but I imagine a lot of buildings took up the Con Ed offer and are currently running with converters in the basement.
Hey, that's not Edison in the pic. I think it's Matthew Perry.
Phase, not faze. Unless that was an elaborate pun about shocking them out of using DC.
I was recently discussing the issues of DC vs. AC with a high power engineering. According to him, DC is making something of a comeback as they're now using it in places in Japan. The big issue with transmitting power long distances is that you want to do it at a high voltage so the current can be low. The reason this was until recently infeasible with DC was that transformers require AC to work. Modern methods of switching power mean that DC-to-DC conversions can be just as efficient.
The safety issue is an interesting one too, despite being an asshole, Edison may have been right about it. Someone will probably disagree with me, but as far as I understand it high-voltage AC will cause you to lock onto it while DC is more likely to throw you free. That said, high voltage (backed by high current for you pendants out there) can fuck you up if it's either AC or DC.
The elephant Edison killed to prove his point was named Topsy. There's a film of him electrocuting her that you can see on a mutoscope (!) at the Coney Island Museum. There's also a guy who works there who looks like The Dude who will tell you Topsy's tragic story in great, colorful detail.
Thomas Edison hates cats.
I recently finished reading "Edison and the Electric Chair: A Story of Light and Death" (http://www.amazon.com/Edison-Electric-Chair-Story-Light/dp/B000BZ6UOE/ref=sr_1_1?ie=UTF8&s=books&qid=1195232016&sr=8-1)
It centered around the battle between AC & DC, with the focal point being Edison's campaign to implement electric chairs as the most "humane" means of execution, provided they were running AC.
Really fascinating book - Edison was opposed to capital punishment his whole life, until he saw an opportunity to leverage it in such a way as to destroy his competition (primarily Westinghouse).
It also provided a fascinating snapshot into the origins of modern day power & illumination.
I strongly recommend it to any BB'ers that are down with Menlo Park.
Thanks for the shout-out, Brian -- I wrote "Edison and the Electric Chair."
If I may add my two cents to a couple of points in the discussion:
1. Tesla's name comes up more often in this thread than is warranted. For starters, it's misleading to refer to "Tesla's alternating current." Westinghouse and the Thomson-Houston Electrical Company were selling AC power before Tesla made his crucial contribution--the AC motor. Tesla's technical contributions to the development of AC systems are undeniable, but when it came to the work of building AC systems in American cities, his role was fairly muted. The same is true of the AC/DC controversy. It was Westinghouse, Elihu Thomson and others, not Tesla, who fought Edison's attempts to portray AC as deadly. If you read through the debates in the era's electrical trade journals, Tesla's name almost never arises.
2. Topsy the elephant was indeed electrocuted in 1903, and an Edison company made a film of it, but Edison himself wasn't involved. (Edison was involved in the killing of dogs and horses at his West Orange lab more than a decade before--tests related to the development of the electric chair.) Topsy died in 1903, 13 years after the first electric chair execution -- by then, AC had more or less won the battle of the currents and the electric chair was an accepted method of execution. Topsy's death had nothing to do with the debates over AC/DC or the electric chair.
Here's what happened: Topsy was a rogue Coney Island circus elephant, and her owners decided they had to kill her. They proposed hanging her from a scaffold with a rope and pulley, but the ASPCA claimed that would be cruel. Instead, Topsy was fitted with copper-lined wooden sandals on her right front and back left legs, and the sandals were wired to a dynamo at the local Edison lighting plant. The film you can find on the Web was shot by the Edison Manufacturing Company.
elephants are pretty far up there on the intelligence list. they're pretty awesome.
also, edison was a jerk.
The story I heard was Topsy went rogue and killed some jackass who fed her a lit cigarette instead of peanuts.
I agree with Quibbler (#4), the main advantage of AC is the efficient voltage transformer. It is more efficient to transmit DC power over long distances than AC power of the same voltage. It is also more efficient to transmit high voltage power over long distances. The problem is that it is very inefficient to change the voltage of DC power, so it ends up being more efficient to go with AC.
I disagree with Squidocto (#8). Over at the Tesla Motors website, there was a discussion about this, and the engineers there realized that even with the best equipment you should always use AC for changing voltage. So even if you have DC equipment like a solar panel charging a DC battery electric car, it's more efficient to convert the DC solar energy to AC, change the voltage, then back to DC to charge the battery (then back to AC to power their AC motor!) than to stick with DC the whole way through. Also, my family lived off the grid for most of my life, integrating hydro, propane, solar, and wind power with batteries via an inverter. We used a big efficient inverter for AC without a problem.
1) I wonder why they don't just use twisted pairs to transmit AC over long distances. (Twice as much wire, true.) Maybe you could set up a scheme with transformers where every 100 miles or so the current reverses phase, viz:
[cut and paste that into emacs if you're not seeing it--the "pre" tag doesn't work right here.]
2) Wonder whether those final few places in NYC will get AC-to-DC converters added in front of the DC-to-AC converters, just because it makes the conversion process more systematic than taking the existing converters out.
#21 Futurenerd -
The idea of twisted pair is to reduce interference and radiation from your lines. The next best thing is to minimize the distance between the pair of lines and that is how powerlines are built. Actually, I don't even really understand your suggestion, but you should keep in mind that you wouldn't want to get two high power lines close to each other.
In other sad news, the Greater Chelsea Whale Oil company announced that they are suspending deliveries of their "Spermacetti Gold Illumination Fuel" as of December 31.
The last of the five buildings in Manhattan that still used whale oil are switching over to kerosene this month.
The goat cart that Greater Chelsea used to deliver glass carboys of whale oil will be donated to the Museum of the City of New York.
40 years ago, my mother sublet an apartment in a landmark West 67th Street building. At that time, all the power in the building was DC. Fine for lights, hot plates, and DC motors, of which more in a moment. Electronics (like a TV) required a noisy "rectifier," in effect, an AC generator run on the DC power. She kept it in a closet to mute the racket whike watching TV.
The transit system today runs largely on 600 volts DC. This is what NYC Transit, Metro North, and the LIRR send out on their third rails, and what Amtrak and NJ Transit put on their catenaries. The choice is quite rational, since DC is more efficient in turning "electrical" energy (i.e., the power itself) into "mechanical" energy (i.e., a turning motor.
NYC Transit has decided, nonetheless, to slowly convert its rolling stock (on the "L" line, for example) to AC, arguing that the motors are subject to less wear, even though each car must include complex conversion circuitry. Take one of the Transit Museum's occasional tours of the maintenance yards and you'll hear a lot of skepticism about this "improvement."
I recently painted Edison with Topsy the elephant:
http://www.shardcore.org/shardpress/index.php/2007/02/01/edison-and-topsy-2006/
and Tesla:
http://www.shardcore.org/shardpress/index.php/2007/01/15/tesla-the-prophet-2007/
I thought that some of your readers might be interested...
"Tesla: man out of time" by Margaret Cheney is a very fun read for those interested in Tesla, Edison, Westinghouse and related antics.
Incidentally, I bugged out on the fact that at the time I was reading it I was living in lower Manhattan and that I could actually go to some of the places that were mentioned in the book.
I scoped out the old site of Tesla's Houston Street laboratory. Sadly, the old building was knocked down when Houston was widened, but you can still go stand on the sidewalk where it once was. If you know the Houston and Broadway area at all, there's a 24 hour pool hall right around there. Next to the pool hall is a Subway restaurant. His lab stood in the location of the Subway restaurant and the street in front of it.