I just came across this, from an admittedly less-than-trustworthy Cracked.com Photoplasty page.
(The graphic says that normal wall plug sockets will soon become obsolete, and that they will become replaced by USB sockets)
It got me to thinking, though… Leaving aside the subjective debates about how cool it would be to replace plug sockets entirely with USB sockets, would this be technically possible and practical?
Can you run a washing machine (say…) from a USB port? I kinda thought that less electricity would go through a USB socket than a standard plug - although I don’t know much about any of this stuff…
While it’s true that USB sockets are far more ubiquitous than they once were, could they be in any way usurpers to the crown of traditional power sockets? And, if not, might there be a future where houses are wired for sockets that transmit power and data through the same conduits?
No, it’s a joke.
A typical US socket can deliver 15A, a USB connection is good for an Amp or two at the most (USB-C can handle more power, though).
ETA: Just compare the size of a single prong on a plug to the size of the entire USB connector.
I certainly can see new houses or apartments being outfitted with USB ports, not to replace AC sockets, but to supplement them. Could be quite handy for some of us.
Many things, like lights, and maybe TVs, will need less power and could be run through a USB socket. Power hungry appliances like washing machines and dryers will not. Neither will anything made by Apple.
It’s far worse than your numbers suggest. Amps aren’t power. Watts are power, and watts = amps * volts. Your 15A power outlet is 120V, giving it a max output of 1800W. USB runs at 5V, so your 2.4A USB outlet maxes out at 12W.
And USB is also much lower voltage than a typical socket (5 V vs. 120). But it’s not the volts or the amps by themselves that actually matter: With the right transformer, you could run a washing machine or a refrigerator on any voltage (or current) you wanted. What really matters, though, is the power, the product of voltage and current, which maxes out at about 5 W for USB, but about 1800 W for that typical wall socket.
Right, full power AC sockets will have to remain for full power equipment, but for a lot of other gear the USB could take over for low-wattage type applications.
Best part of the USB adoption IMO has been already a diminishing in the use of large wall-wart transformers, which often inutilized adjacent sockets, for many items’ AC adaptors.
(In my house I already have to deal wiith how when it was built nobody imagined just how many things to plug in there would exist a generation or two down the road. So virtually every room has a receptacle with a powerstrip hanging on to one of the sockets anyway.)
You can’t run a laptop or computer monitor off of a standard USB port (except tablets and small portable monitors) - they both require more than 12W of power. So USB ports aren’t even sufficient for an office desk, let alone for general purpose power outlets.
USB Type-C can supply 100W, and some laptops are powered through the USB-C port. But that’s still marginal for a decent sized monitor. And USB-C plugs are different shape; you’d need adapters to connect to type-A/B ports.
Those USB included outlets would be wired the same as a regular 120 volt AC house outlet. Plenty of books, videos, and info on that on the internet. Also electrical wiring books sold in home improvement stores.
I would just add for safety, always turn off the main power to your house before working on anything electrical like this (trust me, this advice could save your life)*.
And if you are not familiar with working with electricity, this is simple stuff, meaning an electrician would not charge much to do the work. Be safe and call an electrician.
There are wiring practices in many homes such as “Mutli-Wire Branch Circuits” which can be deadly!
What do you plug into those USB ports? Apple and Android do things differently when detecting how much current they can draw out of a USB port. Then there are the newer standards for charging phones that put out more than 5 volts on the power pins after negotiation.
And if it shorts out and catches fire, there’s no way to turn it off other than to frantically try and guess which breaker that outlet is on in your breaker box, which is generally located quite some distance away from the outlet.
Anything hanging from your outlet adds mechanical stress and is prone to failure from that, but at least with that type you can knock it out of the socket if it catches fire.
ETA: And I’m sure someone makes them with vampire connectors on the back, for an even better chance to catch your house on fire.
Personally, I would trust an integrated UL or CSA certified device made by Cooper or similar to a little square box of dubious manufacture that came with some $25 USB powered device purchased on eBay.
I think a more intriguing question than USB sockets specifically is the type of power delivered. If you really think about it the overwhelming majority of devices people use run on DC power rather than AC. Pretty much all consumer electronics are DC, whether via wall wart or an internal transformer. Incandescent lights (or any resistance heating device like hair dryers, toasters, electric ranges, etc.) don’t care what kind of power they run on, but their LED replacements use DC and thus need a transformer. Solar panels and batteries produce DC current, and you need DC to charge the batteries in an electric car.
About the only things that really need/benefit from AC current are motors. These would be furnace blowers, air conditioners, dishwashers, refrigerators, clothes washers and dryers, garbage disposals, sump pumps, garage door openers, and stuff like that. However those are items that are most often hard-wired or have dedicated circuits, with the exception of things like box fans and vacuum cleaners.
So the question is if there would be a benefit to having DC current available directly from wall sockets for the rest of the day-to-day stuff. Energy savings can be impressive by eliminating all the small inefficient wall warts and other transformers. The question is where would the ideal place be to tap that off the existing AC grid? At the service panel? On the pole at the street, requiring a separate service drop to each customer? At a substation requiring parallel primary and secondary distribution lines?
Of course the real difficulty in such a thing would be the need for dual-wiring a whole building. You’d still need at least some AC convenience outlets to plug in the vacuum cleaner, fans, maybe a humidifier, or who knows what else. Though perhaps anything that’s not in a fixed location will just need to be DC down the road (Roombas for everyone!). I think that’s a more interesting question than whether the sockets become USB (which would suck anyway because it always takes three tries to plug one in :)).
Sadly, providing DC at the wall would reduce efficiency, not increase it.
First of all, there is no DC voltage standard. USB provides 5v, but devices which requires more power use 12v or more. So, you would never be able to have a singe outlet that powered everything. Also, lower voltage requires higher current for the same power, which means that if you had a sufficiently large DC load, the wire sizes would have to be enormous. And, with all that extra current comes I2R power losses, which is why AC is used in the first place.
It would be a bad idea to deliver 110 V AC through a USB port. People would end up frying a lot of devices that were designed for the USB standard, which delivers 5 V DC. There are reasons that different plugs and sockets are designed differently (for instance, in the U.S., 220 V plugs and sockets are incompatible with 100 V plugs and sockets). You really don’t want someone to mistakenly plug a device into the wrong outlet.
Surely, the whole point of a “breaker” is that if an outlet shorts out, the breaker will trip and cut the current. That’s what mine do anyway - maybe yours are different.
