The Last DC Power Grid Shut Down in NYC 533
cell-block-9 writes "Today the last section of the old Edison DC power grid will be shut down in Manhattan. '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.' I guess Tesla finally won the argument."
Re:Tesla won but... (Score:5, Interesting)
DC, actually, nowadays makes a lot of sense. (Score:5, Interesting)
Said all that however, high-voltage DC, a transport technology that starts to make sense nowadays, thanks to high-power solid-state switching elements, has many advantages over AC in terms of losses and cable utilization. You can transport more energy via DC than AC, across the same thickness cable. And you have practically no losses due to parasitic capacitances and inductances. The corona effect is much easier to control, too.
So, if I was forced at gunpoint to make a prediction for the electricity transportation in 150 years from now, I'd say hihg-voltage DC.
Re:Advantages? (Score:5, Interesting)
Another difference is that getting shocked by DC tends to be slightly less dangerous than the same shock from AC. A 110V DC shock to bare (unbroken) skin is is quite mild feeling, where most people in the US have found (sometime or other) than 110V AC is fairly uncomfortable, though usually not particularly dangerous (i.e. for every person who dies of electrocution, an unknown but certainly large number of others are shocked with no real consequence beyond surprise and discomfort).
Re:A powerful, electrifying news story (Score:2, Interesting)
What do they use in Washington?
Re:Advantages? (Score:3, Interesting)
AC power has one HUGE advantage and maybe other smaller ones. You can cheaply and easily step the voltage up and down. Stepping A DC voltage up and down is much more complex. DC to DC converters are getting cheaper and better to the point that people are proposing and building high voltage DC power distribution systems.
Re:Tesla won but... (Score:3, Interesting)
"When I hear the name 'Tesla,' I reach for my revolver."
Re:Advantages? (Score:4, Interesting)
Progress. (Score:5, Interesting)
If you want a feel of old DC equipment from the days when if you wanted power you had to make your own, head down to Pratt Institute (located in Brooklyn on Willoughby ave. and Hall st.). They still have 3 steam driven reciprocating piston dynamos built by Ames Iron Works. They work but are only for show. And to top it off they also have a steam turbine dynamo all of which is hooked to a large open marble panel board with knife switches, carbon arc circuit breakers and blade fuses. The panel is still live on the AC side. The Motor generator I mentioned is still there. You can go down to the Pratt engine room and get a tour from Conrad Milster, the Chief engineer who keeps the place running. The large 1930's brick steam boiler still heats the campus and the surrounding neighborhood. The site is an IEEE land mark and walking down there is like going back in time, a real treat.
Re:uh (Score:3, Interesting)
The failures of democracy aren't democracy itself, but rather of the fact that our implementation of democracy is poor in that it doesn't actually give people the representation in government that they should have. Its too easy to get re-elected, its too hard to break into politics without vast amounts of cash and/or support from existing politicians, its too hard to remove someone who is doing a shitty job, its not nearly transparent enough, the voters don't have more than a token say in most issues as elections are only 'big issue items', and too infrequent to give voters real voices in more mundane items, like patent reform, whether the RIAA should be allowed to sue children, etc. And its too hard to vote. (seriously, the cost and organization to run an election or referendum are an obstacle to effective democracy). First past the post elections wipe prevent minority views from having any voice at all.
There is nothing wrong with democracy. We just don't have a good implementation of one.
Capitalism on the other hand has many REAL flaws, even if implemented perfectly. And a hybrid of capitalism and something else is the only way of fixing it, short of a completely new paradigm like the star-trek-economy where scarcity of resources is pretty much a non-issue.
so please, criticize capitalism. but unless you can enunciate a superior alternative, your criticism means absolutely nothing
Bullshit. The first step in fixing a problem is to identify what the problem is.
But you want solutions to capitalism? Sure, close the borders with any other country that doesn't implement capitalism the same way we do, so that we can compete under a fair system. A great deal of capitalisms problems stem from the comparative advantages of -exploiting- foreign economies that don't have the level of protection of human rights, wages, environment, etc. Or alternatively to closing the borders, treat foreign assets and employees as local ones -- and ensure wages and working conditions and environmental practices are compliant with local standards regardless of where the plant is. Its one thing for there to be a competitive advantage by refining your oil closer to the source, or taking advantage of high unemployment and locating a call centre in its epicenter -- but its something else entirely to exploit a 2nd or 3rd world country to get labour at a fraction of its real value to you.
Second, re-design corporations - make directors accountable personally, make ceos accountable personally.
Third, re-design the stock market so that its focussed on serving INVESTORS not TRADERS. If corporations were interested in satisfying INVESTORS they would take a longer view, but right now all that matters is tomorrows share price and this quarters sales. Only traders care about that.
Third, institute separation of commerce and state. Business should have NO ability to affect or impact on government at all. The biggest problem of capitalism is that its a corrupting force on democracy. Separate them.
I could go on...
Re:Tesla won but... (Score:3, Interesting)
That's pretty typical. Example: who do you think of as the inventor of the telephone? Most people would say Alexander Graham Bell. But one could equally credit Antonio Meucci, Johann Philipp Reis, and Elisha Gray. Meucci especially. He beat Bell to it by over 20 years. But he was an Italian immigrant, spoke only poor English, and was effectively broke.
Example: A couple years ago, I independently came up with this:
http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=4&f=G&l=50&co1=AND&d=PG01&s1=blur&s2=camera&OS=blur+AND+camera&RS=blur+AND+camera [uspto.gov]
Did I patent it? Nope. Why? Because I have about as much ability to manufacture modern cameras as I have to get to the moon. I have no knowledge about how to market such things to other companies, to raise venture capital, or anything of the sort. My variant was actually a bit better than theirs (combining superresolution imaging with blur correction), but, well, too late.
And that's the way things go. It happens all the time, and you'd expect it to. If one person can come up with the idea, why not several people? As tech advancing opens up new possibilities, it's only a matter of time before novel applications of it are invented, independent of who reaches the patent office first.
Re:Advantages? (Score:3, Interesting)
Yep, for ever expanding definitions of "short distances." High voltage high power DC silicon is getting better and cheaper, so we're already seeing a few long-haul DC lines where the reduced radiative losses and increased carrying ability of the cables makes it more efficient. On the other end, DC converters are becoming ubiquitous inside electronics. Google wants to standardize on only one voltage (12V) coming from your computer's PSU, and anything that wants another voltage just has its own converter. All of this will make power distribution and conversion cheaper, smaller, and more efficient. And some places are already moving to distributing DC to the rack-mount cabinets, at (iirc) 48V, and converting DC-DC from there.
On the flip side, I absolutely hate DC converters when trying to do analog work. If you buy a 16-bit analog to digital signal capture board, they run off a switching power supply -- a power supply that generates lots of high frequency noise. I've worked with ones that simply can't do better than about 12-13 bits -- the last 3-4 are basically worthless from the noise. I worked on a project that had need of a voltage monitor on a large battery-powered system involving a large number of sensors and controls. We installed a nice little digital LED voltmeter. It had a tiny, noisy switching converter in it. Not only did it dirty up all our data, it actually kicked back enough noise that it lit up LEDs that should have been electrically isolated from it (capacitative coupling through a long cable). Needless to say, we ripped it out and installed an analog (as in coil, magnet, needle) voltmeter.
Even good (read: expensive, as in $1/W or more) sine wave inverters are a pain. One we worked with produced wonderfully clean AC output -- but also created significant radiated noise, and dirtied up the DC input! Capacitors and ferrite beads helped, but not enough -- we eventually just moved it far away and ran the AC through a long extension cord.
So... DC/DC converters are wonderful for space, efficiency, and cost, but they can be quite the pain to work with if you actually care about having any sort of analog precision anywhere nearby. That sort of noise is amazingly hard to get rid of, and you often can't get rid of all the switching supplies these days.
Re:uh (Score:2, Interesting)
Democracy: people vote and the power and law are made directly (volatile)
Republic: people vote and representatives implement the power and law (slow change over time, more stable)
As for capitalism being fair (or not), my grandma always said, "If you dont work you dont eat."
Fairness doesnt come from the marketting scheme per se, but from ethical practice. There are rich and poor, fair and unfair people. In theory those that do the most valuable work or inovate the most valuable products make the most money. In practice ethics can fail. Given this, capitalism already is the most fair possible marketting scheme avaiable. If you cant put forth the effort to provide a valuable product, you will be poor. In another point if you dont use your brain while practicing the system, you will fall victom to those practicing bad ethics. It is when large groups of people do not use their brains that large groups of people fall to even mediocre semi-fair but marginal ethics. Use your power to fire those companies who's products you dont like. Done in volume even large companies with bad ethics can be put down. It is the assumption of people who feel they have no power that keeps large unethical companies in business. However, lazy fat people rarely care if they are being screwed. Thus, everyone thinks capitalism is unfair.
By contrast, socialism is a system where by many lazy uninventive people with voting power cry that no one has given them anything and politicians wanting power cater to that outcry. Thus the few earners and inovators are forced to support the masses.
In essence, the definition of 'fair' has been skewed.
Interesting book to read (Score:3, Interesting)
Re:Tesla won but... (Score:3, Interesting)
Re:DC vs AC - not true today (Score:3, Interesting)
While there is no reason to replace a three phase AC motor with a DC motor, You might start powering variable-frequency drives directly from a DC distribution system.
Re:DC vs AC (Score:3, Interesting)
With AC, the biggest concern is that you get it through either the heart or the brain, in most cases if you just touch the live wire in your house, you're most likely just going to get a tingle. Without any lasting consequences, worst case, your heart has a wrong rhythm to it. Except for the heart rhythm, that all applies to DC as well.
And for many years that's how electricians figured out if a wire was hot, they'd touch it, ensuring that they weren't grounded, if they got a jolt it was live, and if not it wasn't. That doesn't work with DC, by the time you realize you've hit a live wire, you're probably already badly burned or worse.
In practical terms, the problem is that you don't get that additional chance to avoid the more serious injury with DC. You accidentally put your hand on a cord with a subtly damaged cord, and you don't know it until its too late, with AC, you do that and you'll feel it.
how does that even work? (Score:3, Interesting)
Re:DC vs AC (Score:3, Interesting)
Mercury Arc Rectifiers (Score:5, Interesting)
I think the most beautiful piece of old AC to DC conversion technology was the mercury arc rectifier...apparently these devices were still used on some branches of the NYC subway until late in the 20th century. A video of one in operation can be seen at http://www.youtube.com/watch?v=Rt-a8fxgtno [youtube.com]
A center-tapped transformer was connected to two anodes to form a full-wave rectifier(some had more anodes and were used for 3 phase power), and a pool of liquid mercury was used as the cathode material which would form an arc only if the anode was positive. A keep-alive electrode kept the interior full of vaporized mercury to facilitate the discharge. I'd sure like to have my own. Unfortunately an average sized mercury arc rectifier contains around 2 pounds of liquid mercury, so if it ever broke, my neighborhood would have to be decontaminated, my home razed to the ground, and the rubble buried in a concrete encasement.
Re:DC vs AC (Score:3, Interesting)
Re:Tesla won but... (Score:3, Interesting)
That's not to say that Edison cheating Tesla out of tens of thousands of dollars was a good thing, but Tesla survived that and ultimately ended up working with George Westinghouse. You seem to forget that it was that partnership with Westinghouse which broke the impending Edison DC power monopoly and resulted in the modern power distribution system that we have today. Let's also not forget that it was Tesla who invented the polyphase induction motor, the workhorse of modern industry. Westinghouse recognized the value of that invention early on, and it's what originally brought them together.
All in all, a perfect example of a genius working hand-in-hand with a capitalist to bring something good into the world (although Westinghouse was something of an engineering genius in his own right, with some 360-odd patents to his name.) Edison was a jerk who screwed over one of the world's greatest minds for a few bucks, and who shortly before his death admitted that he was wrong about A.C., and the power system which Tesla had put within his grasp. However, he wasn't the reason that Tesla died broke
Re:Tesla won but... (Score:3, Interesting)
Shesh...they have real servers and it's only read-only activity. As they are using MySQL, it's likely all cached hits to boot. As long as they have the bandwidth, it's likely a trivial load. It's not like