4 ms·

Powering 90% of the things in your house via DC power should be the future, no more switching from DC solar/battery back to AC and then back to DC again for no

by mavhc 5y ago

Powering 90% of the things in your house via DC power should be the future, no more switching from DC solar/battery back to AC and then back to DC again for no reason.

megous 5y ago
Maybe with high voltage DC, but 5V or even 12V DC distribution is a complete no-go/waste of metal.
yboris 5y ago
Semi related question: has anyone come across a product that would let me replace an outlet or a light fixture with a flush (clean design) thing that provides enough power for an LED strip? I don't like having a large DC converter hanging off a switch hanging off an outlet. And I can't have a DC converter hang off a ceiling (nor do I want to wire it directly and hide inside the ceiling either).
- liminalsunset 5y ago
  Amazon sells Leviton (a good/common brand) electrical outlets that support USB C power delivery for ~40USD. You can install one, and connect a USB C PD to DC cable ~20USD to power your LEDs. Your LEDs have to be 30W or less though.
- yurishimo 5y ago
  You need the AC->DC converter somewhere. It either needs to be in the light or outside. There are LED fixtures that include the converter; you decide on what that you like the aesthetic of.
- xen2xen1 5y ago
  I suspect you need POE (power over ethernet), or to at least start from there.
tshaddox 5y ago
The reason is that AC can be easily transformed to very high voltages which allow power transmission over long distances with lower losses. I doubt this is going to change any time soon. Of course, you could still have central DC conversion in your house (or maybe even neighborhood) and use USB or similar in your home’s wall outlets, instead of each device needing its own little power brick.
- asdff 5y ago
  DC is can be better over a certain distance because AC loses a lot of energy to heat. the pacific intertie is DC.
- sbradford26 5y ago
  So back when the electrical grid was being created it was basically impossible to step up and down DC. So it had to be distributed at the voltage it was used at. AC could be stepped up and and down with transformers which reduces losses. Now though that we have the circuitry to step up and down DC fairly easily you can actually get more efficient long distance transmission with DC due to not having to factor in things such as skin effect. I don't think things will change quickly but I do believe we will be seeing more DC systems in the home and workplace in the future since it will also mesh with renewables better. https://en.wikipedia.org/wiki/High-voltage_direct_current#Comparison_with_AC https://en.wikipedia.org/wiki/High-voltage_direct_current#Co...
unnouinceput 5y ago
At 5V and your household needs: 1- refrigerator (400W when it motor is running); 2- vacuum cleaner (1000W when running); 3- TV's/PC's/light-bulbs (around 1000W in the evening when all are running at the same time) - all these amounts to at least ~2.5KW power. Now divide that by 5 and you get the intensity at 500A. Do you have any idea how thick the copper would need to be to allow 500A? a full 1cm x 1cm. Any idea how heavy that going to be? Or how expensive? That's why even for 10m distance AC at 220V is better.
- mavhc 5y ago
  Who's running their vacuum cleaner all evening? My fridge/freezer uses 25 watts average, but the 90% of things I was thinking about was ignoring the heaters and motors, just the lights, computers, speakers etc. Next question, why 5V, when they're talking about 50V. That brings us down to 1/10th the amps. Also this is only inside your house, not for power distribution. Generate your DC power with solar, store it in your car/battery, and power your LED lights, Smart speakers, computers, all the stuff that converts power to DC before it uses it today.
  - Ekaros 5y ago
    25 watts might be average, but what is the peak and consumption during duty cycle?
    - unnouinceput 5y ago
      Exactly my point, but @mavhc didn't get it. You vacuum for 10 minutes, but during those 10 minutes if your refrigerator motor is engaged suddenly your standard 3mm copper wires are going to become white hot and melt and you get a nice warming house fire because you didn't thought of the peak intensity. This statement assumes the 5Vcc as house power outlets.

by mavhc 5y ago

Powering 90% of the things in your house via DC power should be the future, no more switching from DC solar/battery back to AC and then back to DC again for no reason.

megous 5y ago

Maybe with high voltage DC, but 5V or even 12V DC distribution is a complete no-go/waste of metal.

yboris 5y ago

Semi related question: has anyone come across a product that would let me replace an outlet or a light fixture with a flush (clean design) thing that provides enough power for an LED strip? I don't like having a large DC converter hanging off a switch hanging off an outlet. And I can't have a DC converter hang off a ceiling (nor do I want to wire it directly and hide inside the ceiling either).

liminalsunset 5y ago
Amazon sells Leviton (a good/common brand) electrical outlets that support USB C power delivery for ~40USD. You can install one, and connect a USB C PD to DC cable ~20USD to power your LEDs. Your LEDs have to be 30W or less though.
yurishimo 5y ago
You need the AC->DC converter somewhere. It either needs to be in the light or outside. There are LED fixtures that include the converter; you decide on what that you like the aesthetic of.
xen2xen1 5y ago
I suspect you need POE (power over ethernet), or to at least start from there.

tshaddox 5y ago

The reason is that AC can be easily transformed to very high voltages which allow power transmission over long distances with lower losses. I doubt this is going to change any time soon. Of course, you could still have central DC conversion in your house (or maybe even neighborhood) and use USB or similar in your home’s wall outlets, instead of each device needing its own little power brick.

asdff 5y ago
DC is can be better over a certain distance because AC loses a lot of energy to heat. the pacific intertie is DC.
sbradford26 5y ago
So back when the electrical grid was being created it was basically impossible to step up and down DC. So it had to be distributed at the voltage it was used at. AC could be stepped up and and down with transformers which reduces losses. Now though that we have the circuitry to step up and down DC fairly easily you can actually get more efficient long distance transmission with DC due to not having to factor in things such as skin effect. I don't think things will change quickly but I do believe we will be seeing more DC systems in the home and workplace in the future since it will also mesh with renewables better. https://en.wikipedia.org/wiki/High-voltage_direct_current#Comparison_with_AC https://en.wikipedia.org/wiki/High-voltage_direct_current#Co...

unnouinceput 5y ago

At 5V and your household needs: 1- refrigerator (400W when it motor is running); 2- vacuum cleaner (1000W when running); 3- TV's/PC's/light-bulbs (around 1000W in the evening when all are running at the same time) - all these amounts to at least ~2.5KW power. Now divide that by 5 and you get the intensity at 500A. Do you have any idea how thick the copper would need to be to allow 500A? a full 1cm x 1cm. Any idea how heavy that going to be? Or how expensive? That's why even for 10m distance AC at 220V is better.

mavhc 5y ago
Who's running their vacuum cleaner all evening? My fridge/freezer uses 25 watts average, but the 90% of things I was thinking about was ignoring the heaters and motors, just the lights, computers, speakers etc. Next question, why 5V, when they're talking about 50V. That brings us down to 1/10th the amps. Also this is only inside your house, not for power distribution. Generate your DC power with solar, store it in your car/battery, and power your LED lights, Smart speakers, computers, all the stuff that converts power to DC before it uses it today.
- Ekaros 5y ago
  25 watts might be average, but what is the peak and consumption during duty cycle?
  - unnouinceput 5y ago
    Exactly my point, but @mavhc didn't get it. You vacuum for 10 minutes, but during those 10 minutes if your refrigerator motor is engaged suddenly your standard 3mm copper wires are going to become white hot and melt and you get a nice warming house fire because you didn't thought of the peak intensity. This statement assumes the 5Vcc as house power outlets.