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by snickmy 224 days ago
AC makes power distribution easier (because you can have modulated phases). So it's correct to say it's easier to move it over a long distance. Additionally, and i'm really simplifying, at parity of nominal voltage, you can move a lot more power, at a lower dissipation cost. This has resulted in few high power electronics to be AC native (ie.: no AC - DC - AC conversion). Think about motors in the various appliances, etc. It doesn't need to be like that, investment in DC car motors have pushed the industry to optimizes design, and get similar power output of the motor at lower energy consumption.

That said, if you are a manufacturer of an appliance and you have an addressable user base of billions with AC, and a 'potential new user base' with DC... you might just want to swallow the cost and add a DC / AC converter for the sake to not have to produce two variants of the most complex / costly item (the motor in this case).
1 comments
brohee 224 days ago
That wheel has turned. The king of long distance transmission is now HVDC, to be point of sometimes being used intra-grid and not just for interconnects.
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snickmy 223 days ago
That is correct. When that will be available is the hard thing to guess.

There are currently enough production of electricity that is motor based (think about gas turbine, water turbines, etc), so there is a nice benefit of having AC at source and distribution.

The infrastructure needs to change. With an average lifetime of a substation in the 50-75years, it's hard to expect we'll overhaul completely the distribution system over night.

It's also hard for me to understand the power loss between the two scenarios (AC production, ac distribution, ac/dc conversion , dc consumption) and DC production, dc stepup to HVDC, dc distribution, DC stepdown and DC consumption). Even 1% at national scale means millions, so the entire business case might be anchored there. I'm sure there are smarter people than me here that can cast some light on this

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SJC_Hacker 223 days ago
DC is hard to step down. You dont want 10,000 volts going into every house.

AC sill be used for distribution that isnt very long distance

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SJC_Hacker 223 days ago
Long distance yes. But medium distance AC is stíl cheaper.

You also need to step down that voltage to 240/220 for residential use, much easier to do with AC

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