If i leave my charger plugged in and the switch is on without any device charging, does it ‘waste’ electricity? Why/why not?
In: 58
Generally, yes, there will be a small amount of electricity flowing. However, it is so small that it amounts to pennies per year in cost. If you unplugged everything you weren’t using and only plugged it in to use it, there would be no notable reduction in your electricity bill. Most of your bill is major appliances and heating/air conditioning.
If your charger has lights on, or other indicators, then it indeed wastes a tiny amount of electricity (one AA battery worth over years).
Otherwise, not. This is because without the battery/device attached for charging, the circuit is not complete and electricity is not flowing, energy is not being consumed and not being expended into light/heat.
The old AC adapters/chargers that were basically just a transformer + bridge rectifier used to waste a bit of electricity. They would produce heat even when not in use. Modern chargers are a lot more efficient and probably use a negligible amount of current when not powering anything.
Yes, the most coming from LEDs, but also a fair amount coming from the ICs that drive the charger. This is for a few reasons.
One being that some of these ICs might use redumentary voltage dividers to bias a certain input to a specific voltage. You can look up what a voltage divider is, but the jist is that it brings a high voltage down to a lower voltage to be used somewhere else in the circuit.
Another reason so that these controllers will have bypass capacitors that filter out the higher frequency electrical noise from the power source. This will use power for the same reason above, its a passive device that isn’t turned off or on. Just providing clean power to the IC thats on ‘standby’ mode
The final reason is actually that ‘standby’ mode. Its usually rated at a few μA of current. This is due to the intrinsic nature of the MOS transistors in the IC, and how they’re implemented to build the chip. This is pretty not ELI5, but its as close as we can get given that each company has their own chip that works in its own specific way.
remember, cost of electricity with taxes, fees, etc. amounts to about $0.20/kWh (20 cents per kilowatt-hour) at most, for much of the continental US.
A very very high quiescent (passive) current draw for a cell phone charger would be 10mA (0.01 amperes) which is 120V × 0.01A = 1.2W (watts). There are 24×30= 720 hours in a month. 1.2W = 0.0012kW. So the total energy consumption in a month would be 0.0012kW × 720h = 0.864kWh.
At 20 cents per kWh, that’s a whopping 17 cents for the month to leave a very crappy charger plugged in continuously. Even accounting for high peak time rates, and a higher overall rate state like California, it would still be under a dollar.
So from a monetary perspective, no it’s not a waste.
If you mean from a “green” perspective, no, still not a waste. Losses and inefficiencies from power generation and transmission dwarf things like this.
I realize this isn’t a very eli5 answer but it’s not something that can really be explained ly5
What if my charger is plugged into a USB port on a power strip that is switched off but still plugged in the wall? Does that waste electricity?
If it gets warm, even slightly, it’s wasting energy. It’s not *much* energy, but it adds up across many devices.
Yes, but really not much. Your charger, plugged or unplugged, used or not, uses a negligible amount of electricity, unless you are talking about an electric car charger. Appliances that consume the most energy are (water) heaters, AC and fridges basically.
You also need to factor your definition of “wasting” ; typically, you could think using electricity to power lights at night for closed stores is “wasting” but the truth is power plants can hardly regulate their output fast. The result is, if you turn off said lights, the energy that would have been used is produced anyway, but is not billed to a customer.
Chargers shouldn’t be left unattended, primarily because they’re a fire risk. The probability is small but the results are catastrophic. Many fires happen because of crappy chargers every year.
Chargers on standby don’t use a lot of power. It’s insignificant in terms of a personal power bill, but adds up to a substantial amount of *completely wasted energy* when multiplied by millions or billions of people.
Put chargers behind a power switch. Many power strips have one.
Yes. But the amount is usually very small. You can use a device branded a ‘kill a watt’ to measure exactly how much anything that plugs in is drawing at any given time.
It’s also a reason that one of the policies that governments need to pursue to combat climate change is to mandate that any device draws no more than a single watt when idle. When people find out exactly how much power ‘off’ devices actually still draw, it can be shocking.
Latest Answers