AC or DC?

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bolo
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AC or DC?

Post by bolo »

If we were starting over from scratch, would we still have AC electricity distribution or would DC make more sense?

An increasing share of generation is no longer from machinery rotating at 60 Hz (YFMV). Solar produces DC, and while wind produces AC, it's not at a fixed frequency so it's converted to DC immediately anyway. If you store energy in batteries, they produce DC when the energy comes back out again.

On the usage end, lighting is increasingly LEDs, which means each bulb needs its own internal AC-to-DC conversion. Computers and other electronics all want DC, so they all need their own power bricks also, or chargers that take AC input and put out DC to a USB plug or similar.

If it weren't for the obvious costs of changing over, would it better just to use DC throughout?
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Martin_B
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Re: AC or DC?

Post by Martin_B »

I'm trying to remember the physics I learnt at school (~35 years ago now!) but I think high voltage AC is preferable for transmission to prevent current losses, especially over long distance.
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Gfamily
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Re: AC or DC?

Post by Gfamily »

Martin_B wrote: Sun Apr 05, 2026 9:36 pm I'm trying to remember the physics I learnt at school (~35 years ago now!) but I think high voltage AC is preferable for transmission to prevent current losses, especially over long distance.
I had the same school learning (48+ years ago), but I think (then) it was the higher voltage rather than specifically the AC that was preferable.
A quick case of "I do my own research"/"I did a ask of google" suggests that high power DC is generally a bit more efficient than high power AC, and (what surprised me I think) is that DC-DC voltage conversion is 'seemingly'* more efficient than AC-AC voltage conversion.

* based on results posted on page 1 ...
My avatar was a scientific result that was later found to be 'mistaken' - I rarely claim to be 100% correct
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
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