Earlier quoted context omitted.
Olympic swimming pools for liquids, times around the the earth for length and number of double decker busses for height.
Don’t forget cheetahs for velocity and elephants for weight.
Or vice versa.
The 500k-ton typo: Why data center copper math doesn't add up
141–150 of 152 posts
Re: The 500k-ton typo: Why data center copper math doesn't add up
#142The funniest part is beyond the typo, the complete lack of physical intuition from the analysts who circulated this. 500,000 tons is roughly the weight of 1.5 Empire State buildings. If your rack busbars weigh more than the structural steel of the facility housing them, you have a geotechnical engineering crisis on your hands. It is wild that we reached a point where financial modeling is so decoupled from physical r…
Do we think the people pushing new age LLM saviors are more or less stupid?
Re: The 500k-ton typo: Why data center copper math doesn't add up
#143Earlier quoted context omitted.
This is absolutely not true in areas where heating the air and water and cooking are done with natural gas. Every single appliance in a house is more efficient today than in 1970 due to advances in motor speed control, without exception. The only thing that didn’t get more efficient is electric resistive heat and it’s impossible to improve on that anyways. I can’t think of a single appliance from 1970 that consumes l…
Sure, but there are more appliances plugged in today than there were. The simplest evidence for this is that there are never enough outlets in an old (unrenovated) home. In a renovated house, you won't have aluminum wire at all, so these concerns are null. My original statement should be qualified. Since we were talking about aluminum wire it's relevant -- an updated house will have new (copper) circuits that can han…
> Sure, but there are more appliances plugged in today than there were. The simplest evidence for this is that there are never enough outlets in an old (unrenovated) home.
Perhaps, but none of them are continuous load, which absolutely matters.
Rice cookers, microwave, stand mixers, air fryers, pressure cookers, etc are all short duration usage, not continuous load. If homeowners decide not to add dedicated kitchen circuits and instead use a 120V 12A load on a 120V 15A shared circuit and trip the overcurrent protection, that’s their own fault.
These loads don’t really matter in the way a heat pump, air conditioner, furnace fan, or water heater does, it’s a bunch of random kitchen appliances that you won’t be using simultaneously. Your utility does not even take the full non-continuous load into account when calculating the kVA demand of your electrical service. IIRC a random convenience duplex receptacle for non-continuous loads only adds like 180 VA (this is 1.5A at 120V with a power factor of 1) to the demand calculation.
You are correct in a technical sense that people have more devices they plug into a wall, but most of the power consumed by a home is to devices that are hardwired in, aka continuous loads, not cord and plug connected appliances.
The continuous load of a home should be lower than ever without electrifying heat. Every continuous load (which are almost exclusively motors and lighting) in a home is more efficient now than in the past due to variable frequency drives and electrically commutated motors.
Re: The 500k-ton typo: Why data center copper math doesn't add up
#144With regards to the copper market: it keeps surprising me that some people seem to assume copper is a hard requirement for conducting electricity. In reality copper is just convenient . We use it because it's easy to work with, a great conductor, and (until recently) quite affordable. But for most applications there's no reason we couldn't use something else! For example, a 1.5mm2 copper conductor is 0.0134kg/m, whic…
Most residential 200A electrical panels use tin plated aluminum busbars. https://www.eaton.com/cr/en-us/catalog/power-connections/bus...
Most commercial panelboards and transformers also use aluminum buss.
Re: The 500k-ton typo: Why data center copper math doesn't add up
#145Earlier quoted context omitted.
I am not an electricity/wiring guy so maybe you can help me understand. I thought aluminum is dangerous to wire with because it is a fire hazard (I bought a home this year and this was a prominent warning in my reading). Is that because it needs to be done very carefully? I imagine most data centers would not mess with a fire risk on such a scale.
It's because aluminium has a higher coefficient of thermal expansion. It expands and shrinks more as it heats, and as those cycles add up it tends to loosen electrical connections. Loose connections have higher resistance, heat up and can cause fires. That said, there is no reason we can't design better connectors that can withstand the expansion and shrinkage cycles, like spring loaded or spring cage connectors.
Wiring devices have almost all been universally rated for Al/Cu conductors for the last 50 years, what you’re talking about only lasted a handful of years in the early 1970s.
Go look at the terminals on any light switch or receptacle at Home Depot, they’re all Al/Cu rated.
Re: The 500k-ton typo: Why data center copper math doesn't add up
#146With regards to the copper market: it keeps surprising me that some people seem to assume copper is a hard requirement for conducting electricity. In reality copper is just convenient . We use it because it's easy to work with, a great conductor, and (until recently) quite affordable. But for most applications there's no reason we couldn't use something else! For example, a 1.5mm2 copper conductor is 0.0134kg/m, whic…
AFAIK Aluminum wires will become a heat liability, especially at higher amps
You are incorrect.
Wire can be used for up to whatever ampacity is listed for that size wire and temperature rating in Table 310.16 (Conductor Ampacity) Copper and aluminum have separate ampacity tables because you need to use larger aluminum conductors.
Example:
#250MCM THHN copper can handle 255A in a commercial setting (75C column)
#250MCM THHN aluminum can handle 205A in a commercial setting (75C column).
NEC ampacity table: https://media.distributordatasolutions.com/ThomasAndBetts/v2...
Re: The 500k-ton typo: Why data center copper math doesn't add up
#147Earlier quoted context omitted.
> In reality copper is just convenient. We use it because it's easy to work with, a great conductor, and (until recently) quite affordable It's convenient, it's easy to work with, great conductivity, and cheap enough all at the sametime... Dude, I think you just explained why cropper is used instead of anything else.
> and cheap enough Not anymore. :(
Wire has barely gone up in price, I was paying $175 for 1000’ of #12 THHN a year ago and today it’s about $190 for 1000’ of #12 THHN.
It’d be nice to get 1000’ of 12-2 MC cable for $500 again, but those days are gone.
Re: The 500k-ton typo: Why data center copper math doesn't add up
#148Earlier quoted context omitted.
Sure, but there are more appliances plugged in today than there were. The simplest evidence for this is that there are never enough outlets in an old (unrenovated) home. In a renovated house, you won't have aluminum wire at all, so these concerns are null. My original statement should be qualified. Since we were talking about aluminum wire it's relevant -- an updated house will have new (copper) circuits that can han…
> Sure, but there are more appliances plugged in today than there were. The simplest evidence for this is that there are never enough outlets in an old (unrenovated) home. Perhaps, but none of them are continuous load , which absolutely matters. Rice cookers, microwave, stand mixers, air fryers, pressure cookers, etc are all short duration usage, not continuous load. If homeowners decide not to add dedicated kitchen…
... but unless I'm mistaken, (something closer to) instantaneous load is the important factor for aluminum wire thermals.
Varying high loads are more significant than a continuous medium load in terms of the effects on wiring junctions.
Re: The 500k-ton typo: Why data center copper math doesn't add up
#149Earlier quoted context omitted.
Just to make it even more real: During covid I added a sub-panel and the wire (more like the sausage given the girth) between the sub-panel and main panel was aluminum because of cost. You just need to be a tad careful at the connection points with copper -- nothing a caring literate person can't handle
Did you use antioxidant paste on all of the aluminum terminations? If you didn’t, please pay an electrician to come fix it. If you did apply the paste, you are in the 0.01% of non-idiot non-electrician homeowners and can skip my rant about homeowners doing electrical work in the next paragraph. I sell electrical work and have seen some incredibly poor work done by homeowners. Do not install aluminum wire if you are a…
Kind of overstating things here. Noalox has not been required for modern materials made in like the last 30 years.
Re: The 500k-ton typo: Why data center copper math doesn't add up
#150The funniest part is beyond the typo, the complete lack of physical intuition from the analysts who circulated this. 500,000 tons is roughly the weight of 1.5 Empire State buildings. If your rack busbars weigh more than the structural steel of the facility housing them, you have a geotechnical engineering crisis on your hands. It is wild that we reached a point where financial modeling is so decoupled from physical r…
The world of financial analysis and modeling is broad. It’s common to give these tasks to juniors and expect them to grind through it when the output doesn’t really matter. In this case the output wasn’t actually used for financial modeling. If it had been, it would have been caught immediately when someone put it into a table where they calculated the price or the supply constraints or anything else.
And anything to do with AI valuation is in la-la-land, so it's not that surprising that a set of made-up values is based on another made-up (or at least erroneous) value.