9 ms·

Alternating Current is Stupid – Everything we own has to convert to DC anyway

1 points by jermaustin1 5y ago

CelticBard 5y ago
This is the stupidest thing I've seen in a while. Wow
- version_five 5y ago
  I think it might be a joke. Either that or it's a good reminder why fundamentals are important.
  - jermaustin1 5y ago
    Hyperbole, but not a joke. Our current infrastructure is based around AC because it was the superior technology in 1880s. It won the current wars. It was the superior technology until just recently. (U)HVDC is more efficient at transmitting power over long distances. Solar power generation is becoming more viable. And local grids are going to become more necessary than ever. All of that points toward DC being the better candidate for power generation and use in the future. Obviously AC is still needed today, and will be for a long time while DC technology keeps ramping up. RVs and Boats and tiny homes are all increasingly switching to full DC appliances with no inverters. But to consider that the argument between AC and DC is settled 150 years ago neglects the technology we have today.
Thetawaves 5y ago
The crux of this post seems to be that energy conversion = inefficient = bad. I am still trying to figure out what this has to do with AC - energy conversion losses would be present regardless of whether or not mains is AC or DC.
PragmaticPulp 5y ago
This is not a great overview of the tradeoffs. It’s a one-sided rant that pretends AC doesn’t have any benefits, which any power engineer can tell you isn’t true.
- jermaustin1 5y ago
  It is a one-sided rant. I even call that out toward the bottom. AC is very beneficial, and has been for 150 years, but that has caused DC power generation and distribution to be neglected. DC transmission is much more efficient over long distances, making continent scale grids more viable, and with more and more of our house running on DC, it only makes sense to start transitioning to DC inside the house with AC used where it makes sense (induction motors and large appliances and heating), but even those we need to focus on replacing with more efficient DC motors and greener heat pump technology that uses geothermal or similar. I thought I was being cute with the post, but it seems people took it way too seriously. DC generation, transmission, storage, and use are becoming a lot more common, especially in "micro-grids"/off-grid use. I'm not saying that this is common place yet, but maybe it will be soon.
retrac 5y ago
The power distribution side of it has not changed much. Stepping voltages up and down at scale (kilowatts to hundreds of megawatts) is still much easier with AC and transformers, than DC-DC conversion using power electronics. On the grid DC transmission is only done where the gains in transmission efficiency and reduction in the amount of conductor needed can offset the substantial cost of the terminal equipment. Affordable solid-state DC-DC converters that could take the place of the typical substation or last-step utility pole transformer just don't exist.
beardyw 5y ago
Why post 4 stories on the same subject? [Edit - help there's more] Previously discussed / debunked here: https://news.ycombinator.com/item?id=29350915 https://news.ycombinator.com/item?id=29350915
- jermaustin1 5y ago
  If we keep doing things the same way we do them now, yes, DC cannot replace AC. Heaters cannot run on DC without fat wires, but why are we running electric resistive heating? Electric cooking requires fat wires on DC, but why are we using resistive heating. Air conditioning requires a lot of electricity, but low power DC heat pumps exist, and geo thermal exists and is viable even on smaller plots of land using various coils. 12V DC is perfectly fine to replace all the wiring for our lights, and our plugs that are mostly used to convert the AC power back to DC in electronics. For the bigger appliances, there are 48V and 96V options that are used in RVs and tiny homes, and have been for decades. DC at the home is quite viable if you shift your view from an AC only world.

1 points by jermaustin1 5y ago

CelticBard 5y ago

This is the stupidest thing I've seen in a while. Wow

version_five 5y ago
I think it might be a joke. Either that or it's a good reminder why fundamentals are important.
- jermaustin1 5y ago
  Hyperbole, but not a joke. Our current infrastructure is based around AC because it was the superior technology in 1880s. It won the current wars. It was the superior technology until just recently. (U)HVDC is more efficient at transmitting power over long distances. Solar power generation is becoming more viable. And local grids are going to become more necessary than ever. All of that points toward DC being the better candidate for power generation and use in the future. Obviously AC is still needed today, and will be for a long time while DC technology keeps ramping up. RVs and Boats and tiny homes are all increasingly switching to full DC appliances with no inverters. But to consider that the argument between AC and DC is settled 150 years ago neglects the technology we have today.

Thetawaves 5y ago

The crux of this post seems to be that energy conversion = inefficient = bad. I am still trying to figure out what this has to do with AC - energy conversion losses would be present regardless of whether or not mains is AC or DC.

PragmaticPulp 5y ago

This is not a great overview of the tradeoffs. It’s a one-sided rant that pretends AC doesn’t have any benefits, which any power engineer can tell you isn’t true.

jermaustin1 5y ago
It is a one-sided rant. I even call that out toward the bottom. AC is very beneficial, and has been for 150 years, but that has caused DC power generation and distribution to be neglected. DC transmission is much more efficient over long distances, making continent scale grids more viable, and with more and more of our house running on DC, it only makes sense to start transitioning to DC inside the house with AC used where it makes sense (induction motors and large appliances and heating), but even those we need to focus on replacing with more efficient DC motors and greener heat pump technology that uses geothermal or similar. I thought I was being cute with the post, but it seems people took it way too seriously. DC generation, transmission, storage, and use are becoming a lot more common, especially in "micro-grids"/off-grid use. I'm not saying that this is common place yet, but maybe it will be soon.

retrac 5y ago

The power distribution side of it has not changed much. Stepping voltages up and down at scale (kilowatts to hundreds of megawatts) is still much easier with AC and transformers, than DC-DC conversion using power electronics. On the grid DC transmission is only done where the gains in transmission efficiency and reduction in the amount of conductor needed can offset the substantial cost of the terminal equipment. Affordable solid-state DC-DC converters that could take the place of the typical substation or last-step utility pole transformer just don't exist.

beardyw 5y ago

Why post 4 stories on the same subject? [Edit - help there's more] Previously discussed / debunked here: https://news.ycombinator.com/item?id=29350915 https://news.ycombinator.com/item?id=29350915

jermaustin1 5y ago
If we keep doing things the same way we do them now, yes, DC cannot replace AC. Heaters cannot run on DC without fat wires, but why are we running electric resistive heating? Electric cooking requires fat wires on DC, but why are we using resistive heating. Air conditioning requires a lot of electricity, but low power DC heat pumps exist, and geo thermal exists and is viable even on smaller plots of land using various coils. 12V DC is perfectly fine to replace all the wiring for our lights, and our plugs that are mostly used to convert the AC power back to DC in electronics. For the bigger appliances, there are 48V and 96V options that are used in RVs and tiny homes, and have been for decades. DC at the home is quite viable if you shift your view from an AC only world.