6 ms·
I had heard the parts about "probably wouldn't be a big deal for CPU performance" and "probably wouldn't be great for energy storage", but I hadn't heard the po
by drdeca 3y ago
I had heard the parts about "probably wouldn't be a big deal for CPU performance" and "probably wouldn't be great for energy storage", but I hadn't heard the point about "we use less efficient materials for power grid transmission than we could, because of costs".
I suppose I didn't expect that we necessarily had like, the "absolute most efficient that could be made" (if that is something substantially more complicated at a materials-science level than "some simple-to-make-alloy"), but I hadn't imagined that it was a substantial difference. (I think I had imagined that they were... copper wires with like, surrounding metal tubes, or something? I hadn't thought much about it.)
Could you either say, or give my a search term I should look up in order to read, a little more about the trade-off being made between materials cost and efficiency of transmission lines?
- cogman10 3y agoThe crux of the problem for superconductors used as power delivery is the "critical field" problem. [1] Super conductors are superconductive to a point. Once that point is crossed they turn into regular conductors. (I've seen ~1A cited. For context, EVs charge at around 500A). To make them useful for power transmission, you'd have to up the voltage to insane levels to avoid collapsing the field. [1] https://en.wikipedia.org/wiki/Critical_field https://en.wikipedia.org/wiki/Critical_field
- Eduard 3y agoor just go the straightforward way and use several transmissions in parallel, as it is already done for existing superconducting lines in production. The AmpaCity project in Essen, Germany, gives insights about the implementation details, as the involved parties were required to publish their work. https://www.enargus.de/pub/bscw.cgi/?op=enargus.eps2&q=%2201097305/1%22 https://www.enargus.de/pub/bscw.cgi/?op=enargus.eps2&q=%2201... for the specific aspect under discussion, the Karlsruhe Institute of Technology report is of interest: https://www.tib.eu/de/suchen/id/TIBKAT:872231372/Ampacity-10kV-Supraleiter-System-f%C3%BCr-Hochenergietrassen?cHash=444bf283113199a60b2eecd1f880c5d8 https://www.tib.eu/de/suchen/id/TIBKAT:872231372/Ampacity-10...
- floxy 3y agoSuperconductors have a critical current density (Ampere/m^2) that varies with temperature and external magnetic field[0]. So if you want more current, you need to use a bigger wire (and/or make it cooler). YBCO HTS tapes have enough current density for power transmission[1]. [0] https://en.wikipedia.org/wiki/Yttrium_barium_copper_oxide#/media/File:YBCO-IG_A_vs_T.svg https://en.wikipedia.org/wiki/Yttrium_barium_copper_oxide#/m... [1] https://www.amsc.com/comed-and-amsc-announce-successful-integration-of-resilient-electric-grid-system-in-chicago/ https://www.amsc.com/comed-and-amsc-announce-successful-inte...
- svetb 3y agoAm not the author of that comment, but the fact that comes to mind is that aluminum is used for virtually all transmission and distribution lines - for price reasons - even though copper has better conductivity. If we did discover a room-temperature superconductor, I suspect it would be a while before the cost to produce it in the bulk quantities required for electrical transmission are economically attractive compared to what’s already available.
- Joker_vD 3y agoIn some desperate places, people would cut down aluminum power lines and sell them to scrapyards for some quick buck. But copper power lines? Those would be in a similar danger in many more places.
- Roark66 3y agoNot only in desperate places. I heard last year (or the year before) someone stole few km of train wire in Germany. Although to this day some people think it was a Russian sabotage rather than genuine theft. Previously (for example in Poland) I used to hear about things like this all the time until maybe a decade ago.
- AlGrothendieck 3y ago[flagged]
- pbhjpbhj 3y agoThey steal buried copper cables in rural locations (UK) by attaching one end to a truck and driving off. Mostly seems to be communication lines.
- lazide 3y agoTying a high voltage power line to a truck is a recipe for an exploding/melting truck, long before someone could pull it down. Communication/low voltage is a different matter of course.
- MobiusHorizons 3y agoWe frequently use aluminum wires with a higher thickness to make up for the lower conductivity as compared to copper. It’s not as simple as cost vs performance though, as aluminum is substantially less dense than copper. Gold and silver are also better conductors than copper, but of course are very expensive, and still have resistance. Zero resistance may be with it on some cases. For instance in projects that currently use high voltage dc it may be worth it due to safety and complexity wins, but that all would depend on how hard (expense and complexity) the superconductor is to deploy.
- cf141q5325 3y ago>We frequently use aluminum wires with a higher thickness to make up for the lower conductivity as compared to copper. Aluminum wires even made it into residential housing when copper was expensive/rare. https://en.wikipedia.org/wiki/Aluminum_building_wiring https://en.wikipedia.org/wiki/Aluminum_building_wiring
- stoobs 3y agoCan confirm, my parents had an aluminium telephone line in the UK until it failed and had to be replaced. Moot point as it's replaced with a fibre optic cable now though.
- cf141q5325 3y agoThe problem is with their usage as mains power. I think they are considered a fire hazard in older German homes.
- stoobs 3y agoNot surprising, any degradation in the connection leads to intermittent connection/high resistance fault = heat and poof, there it goes.
- ithkuil 3y agoNo only silver is a better conductor than copper. Gold is worse.
- TylerE 3y agoA 2" diameter copper wire will have lower losses than a 1" diameter copper wire. Copper is expensive so over hundreds of miles you may not want that.