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Slow Electricity: The Return of DC Power? (2016)

lowtechmagazine.com

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Re: Slow Electricity: The Return of DC Power? (2016)

#2
What might realistically happen for this to be achievable in an existing or new home? Or as a default for new homes?

I camp a bit and spend more than enough time dealing with 12V lighting, recharging drone batteries from car/aux batteries, etc. Always end up wondering how much of my house actually needs AC, where in the house that occurs (fridge, ducted heating/cooling unit?) and what could get by without it. More and more of my power tools are battery based too. Would AC to the kitchen and garage be enough?

Re: Slow Electricity: The Return of DC Power? (2016)

#3
We're currently in the process of designing a house that we hope to build early next year. One thing that I dream of doing is lighting the entire house with LEDs wired in a low voltage DC "network." Even better if they're addressable, dimmable, even RGB recolorable.

Power over Ethernet would be a pretty cool way of doing it if it was practical...that way you get the data to control the lights as well as the power to run them.

Does anything like this exist in a way that won't get me fired by the builder for even mentioning it?

Re: Slow Electricity: The Return of DC Power? (2016)

#4
post #3

We're currently in the process of designing a house that we hope to build early next year. One thing that I dream of doing is lighting the entire house with LEDs wired in a low voltage DC "network." Even better if they're addressable, dimmable, even RGB recolorable. Power over Ethernet would be a pretty cool way of doing it if it was practical...that way you get the data to control the lights as well as the power to…

Low voltage electrical is entirely doable and no issues code wise. If you have them run low voltage conduit to wherever you want, you should be good to go.

Just be aware many jurisdictions have minimum lighting requirements that your low voltage lights may not meet, but you could always just leave those lights off

Re: Slow Electricity: The Return of DC Power? (2016)

#5
This doesn’t make any sense. Power transmission with DC still requires high voltage for any reasonable efficiency. Then you have to convert it back down to a residential voltage (still probably >100V for conductor material efficiency) and then devices have to convert that down to low voltage. So you’re not actually saving any conversion steps. On top of that, you have to use DC-DC power electronics, which are much more expensive than transformers etc. at high power levels.

There is an argument for using DC over AC but avoiding conversion losses is not a compelling part of it.

Re: Slow Electricity: The Return of DC Power? (2016)

#6
post #3

We're currently in the process of designing a house that we hope to build early next year. One thing that I dream of doing is lighting the entire house with LEDs wired in a low voltage DC "network." Even better if they're addressable, dimmable, even RGB recolorable. Power over Ethernet would be a pretty cool way of doing it if it was practical...that way you get the data to control the lights as well as the power to…

Low voltage residential wiring is not very efficient for most applications because the conductors have to be so much larger.

Re: Slow Electricity: The Return of DC Power? (2016)

#7
post #2

What might realistically happen for this to be achievable in an existing or new home? Or as a default for new homes? I camp a bit and spend more than enough time dealing with 12V lighting, recharging drone batteries from car/aux batteries, etc. Always end up wondering how much of my house actually needs AC, where in the house that occurs (fridge, ducted heating/cooling unit?) and what could get by without it. More an…

Motors, compressors still are more efficient on AC, for place like American South where air conditioning represent largest segment from electricity expense AC grid remains making sense.

Re: Slow Electricity: The Return of DC Power? (2016)

#8
post #3

We're currently in the process of designing a house that we hope to build early next year. One thing that I dream of doing is lighting the entire house with LEDs wired in a low voltage DC "network." Even better if they're addressable, dimmable, even RGB recolorable. Power over Ethernet would be a pretty cool way of doing it if it was practical...that way you get the data to control the lights as well as the power to…

low voltage is just not a good way to send high amounts of current over even moderately long distances, because low voltage means higher current, which means higher losses to resistance in your wiring, which means you will need much much thicker wiring.

Re: Slow Electricity: The Return of DC Power? (2016)

#9
Almost every type of DC-DC conversion requires some intermediate AC conversion anyway.

And surprise, a lot of DC-DC topologies require a transformer too.

Transformers still soundly beat solid state conversion on cost, and efficiency at above the wall outlet voltages.

You can't run away from that entirely. If you were to give a free hand to a good EE to redesign the electric grid from scratch, I doubt the result will differ much from what the world has already.

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