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Data centers are transitioning from AC to DC

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Re: Data centers are transitioning from AC to DC

#211

Post by wil421 »

boomskats wrote: post #202
chrneu wrote: post #104

Earlier quoted context omitted.

the internet really needs to stfu about tesla and get over that oatmeal comic that spawned a billion internet myths. dude was a decent inventor but suffered from chronic mental health issues and, in his lifetime, wasted so much time/energy/money and burned so many bridges with his horrible attitude. there's a reason most people didnt like him in his day, he was a depressed asshole who alienated everyone around him, a…

I mean yeah, but it's not like the guy's 'horrible attitude' came from nowhere. He naiively romanticised migrating to the US thinking the game was about scientific progress rather than capital, and so he got repeatedly screwed over by almost everyone around him for decades. If I was in his position I'm not sure I'd have taken it as well as he did.

There’s no way he suddenly developed autism or whatever mental illness plagued him upon arrival to American. Like most absolute geniuses he struggled in other areas. He said he had visions as a child.

Re: Data centers are transitioning from AC to DC

#212

Post by ansgri »

SoftTalker wrote: post #142
jacquesm wrote: post #53

Earlier quoted context omitted.

Not going to happen. For the same reason that the US never converted to a higher domestic voltage even though there are many practical advantages. The transition from one system to another at the consumer level would be terrible, even if there would be some advantage (and I'm not sure the one you list is even valid, you'd get DC-DC converters instead because your consumers typically use a lower voltage than the house…

I'm not sure it's likely, but I could see DC lighting start to happen in new construction. Have a single AC-to-DC converter off the main service entrance that powers hard-wired LED lighting fixtures in the house. Would probably be better than running the individual (and usually very low quality) converters in dozens of standard LED light bulbs. Would need to be standardized, codified, etc. so probably not happening s…

Would be more practical to have a single 50-300W AC-DC 24V PSU per room or group of rooms, then pull relatively short DC cables to each light. A multichannel light controller could also be placed nearby, and then if you need fully-featured brightness and color control, only a small PWM amplifier could be placed at each light if distance from controller to each light is too long to transmit PWM power directly.

Re: Data centers are transitioning from AC to DC

#213

Post by swed420 »

mjuarez wrote: post #35
bluGill wrote: post #16

Earlier quoted context omitted.

48vdc was common in phone exchanges. They filled the basement with lead-acid batteries and to could run without the grid for a couple weeks. In turn the phone was 99.999% reliable for decades.

Not to be _that_ guy, but it was technically -48V DC. Honestly, that was pretty surprising to me when I had to work with some telco equipment a couple of decades ago. To this day, I don't think I've encountered anything else that requires negative voltage relative to ground.

> I don't think I've encountered anything else that requires negative voltage relative to ground

Automotive collectors can probably still relate to cars from the 1920s-50s having a "positive ground."

Re: Data centers are transitioning from AC to DC

#214

Post by nkrisc »

bananaflag wrote: post #206
mikkupikku wrote: post #178

Earlier quoted context omitted.

There's a component of modern culture that trains and expects people to be extremely pessimistic about long term human development. It results in situations above, where without any further information people just assume by default that were going to run out of a thing and are on some collision course with not just a disaster, but every single conceivable one. (Gallium is a byproduct of aluminum production. We aren't…

On the other hand, it is possible to run out of a metal when all of it is either somewhere in some device or scattered among landfills (i.e. not concentrated in a place like a mine).

That’s still not running out. It’s still there, just more effort to get.

Re: Data centers are transitioning from AC to DC

#215

Post by nkrisc »

threetonesun wrote: post #198
mikkupikku wrote: post #178

Earlier quoted context omitted.

There's a component of modern culture that trains and expects people to be extremely pessimistic about long term human development. It results in situations above, where without any further information people just assume by default that were going to run out of a thing and are on some collision course with not just a disaster, but every single conceivable one. (Gallium is a byproduct of aluminum production. We aren't…

My understanding of most elements is if we want more it’s either pretty easy to make from something else we have a lot of, or we need to redo the Big Bang, the latter being, in my opinion, a bit of a disaster scenario.

Even synthesizing helium is prohibitively expensive. Unless you want whatever heavy decay products we have from nuclear waste, synthesizing elements at industrial scale probably isn’t happening.

Unless by “make from something” else you mean extract the element from existing chemical compounds found in Earth, in which case we’re still just using existing deposits on Earth.

Re: Data centers are transitioning from AC to DC

#217

Post by myrmidon »

ta9000 wrote: post #160
teleforce wrote: post #121

Earlier quoted context omitted.

>It is absolutely stupid to talk about this as edisons revenge. If Tesla had the modern high power transistors needed to get high voltage dc out of the ac produced from a spinning turbine he would be all for high voltage dc too. This! The soon people realized these facts the better. The pervasive high rise buildings did not happen before the invention of modern cranes. Exactly twenty years ago I was doing a novel res…

Does that mean when we run out of Ga there are no more LED TVs?

Sidenote: Whenever someone tells you that (vital) reserves of some ressource are going to run out soonish (implying drastic consequences), you should be extremely skeptical:

Such predictions have an abysmal historic track record, because we tend to find workarounds both on the supply side (=> previously undiscovered reserves) as well as flexibility on the demand side (using substitutes).

This applies historically for oil, lithium, rare earth metals and basically everything else.

edit: I'm not saying we're never gonna run out of anything-- I'm just saying to not expect sudden, cataclysmic shortages in general, but instead steadily rising prices and a somewhat smoothish transition to alternatives.

Re: Data centers are transitioning from AC to DC

#218

Post by bluGill »

tinyhitman wrote: post #197
crote wrote: post #188

Earlier quoted context omitted.

Because the chassis is connected to ground (as in, a literal grounding rod hammered into the soil) and by definition your 0V reference point. The crucial difference is the direction in which the current is flowing: is it going "in to", or "out of" a hot wire? This becomes rather important when those wires are leaving the building and are buried underground for miles, where they will inevitably develop minor faults. W…

Do you also happen to why this is not more common? Must be useful for more than just telephone wires.

Most large scale systems are AC because transformers are relatively cheap, low maintenance, and efficient. When the system is AC ground makes no difference.

With DC systems you generally think about the issues - which is why modern cars are negative ground. However other than cars most people never encounter power systems of any size - inside a computer the voltages and distances are usually small enough that it doesn't matter what ground is. Not to mention most computers don't even have a chassis ground plane (there are circuit board ground planes but they conceptually different), and with non-conductive (plastic) cases ground doesn't even make sense.

Re: Data centers are transitioning from AC to DC

#219

Post by bluGill »

beAbU wrote: post #164
idiotsecant wrote: post #65

Earlier quoted context omitted.

I still have a bunch of 48vdc comms gear in my powerplant.

Why do you have a powerplant?

Power plant is the convention for any large company that has backup power. A few UPSes for the server room - they are the power plant. A backup generator - power plant. Sometimes even just the room with all the break boxes from where the grid comes in is called the power plant (though normally power plant is reserved for backup power). It is extremely common for commercial buildings to have their own power plant. Most of their power comes from the grid in all cases, but they have a power plant. At commercial scale you can often save money by buying a backup generator powerful enough for your whole building so you disconnect from the grid when grid power is in highest demand (see your utility, then your accountant: for details if you can afford a generator this large)

Re: Data centers are transitioning from AC to DC

#220

Post by pixl97 »

jcattle wrote: post #200
ta9000 wrote: post #187

Earlier quoted context omitted.

[flagged]

From your earlier comment, your curiosity was more about what happens after we run out. In your question you stated the running out as a given fact ("When" we run out, not "if"). If that was what you wanted to say I can't tell you, but that's definitely how it was received and thus you also got the harsh response. Since it reads a lot like doomsday thinking. (Example: Does that mean when we run out of oxygen there ar…

?Why would we run out?)

Of oxygen, because of rising temperatures interacting with rock weathering binding all the oxygen.

Now, that's more of something to worry about at geological time scales, but Earth in fact, is not infinite.

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