this post was submitted on 28 May 2025
330 points (83.7% liked)
Technology
70440 readers
3877 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related news or articles.
- Be excellent to each other!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, this includes using AI responses and summaries. To ask if your bot can be added please contact a mod.
- Check for duplicates before posting, duplicates may be removed
- Accounts 7 days and younger will have their posts automatically removed.
Approved Bots
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
I'm not defending the article, but I think most overhead power lines are aluminium, which is probably good as it's abundant compared to copper.
Aluminium is very commonly used. It isn't near as good a conductor as copper, but you can easilly use more toeget results and in most cases that works fine.
The reason we stopped using aluminimun more is it is relly tricky. when you tighten a screw the al deforms over time and so you don't get a lasting connection. Al also corrodes to a non conductive state. Many house fires were traced to al wiring in just the few years it was common. We can mitigate all the above issuses but it takes care and so copper is preferred despite al being much cheaper.
Aluminium conducts better per weight. Copper per volume.
https://en.m.wikipedia.org/wiki/Electrical_resistivity_and_conductivity
They stopped putting aluminum in homes, because it has a tendency to overheat more. The aluminum expands and contracts with load more than copper, which can loosen contact points and encourage oxidation, which then increases resistance and heat. Hot wires in the walls and outlet boxes are no bueno.
The problem with aluminum is that it gets REALLY hot when current is run through it. It used to be ised to wire homes, but is now banned because it wasn't safe.
That's incorrect. Aluminium is about 30% worse by volume than copper, meaning you need to go up a size. What stopped it being used for houses was that the terminations weren't good enough, because aluminium has different thermal expansion and corrosion properties, plus they were using much worse alloys. That's now mostly fixed and if you're in the US, there's a very good chance that your service main is aluminium, and there's talk of allowing copper-clad aluminium (CCA) for subcircuit wiring.
Per mass, aluminium is a better conductor, which is why it's almost exclusively used overhead and in pretty significant volumes underground. The power grids were built on ACSR.