4 ms·

Phone chargers - the truth

8 points by nickb 18y ago

jwilliams 18y ago
Every little bit helps. 0.01% of energy is still a lot of energy... Besides, what it does indicate is a culture around energy. Another problem is a proliferation of chargers. Instead of having one plugging in, people have two, or three, or a dozen. If there were better standards, you could have fewer, bigger, more efficient chargers. I'm not sure if this is addressed in USB3.0 (I'm pretty sure it's not), but there is an opportunity there to bring in a universal charger - that is smart and efficient at the same time.
- bestes 18y ago
  It creates a culture of nonsense. How can a message based on facts get through this noise?
  - jwilliams 18y ago
    What's factually incorrect? When you have a charger plugged in with nothing connected, then 100% of the energy consumed goes to no useful work. Did you see the original BBC article? It also doesn't claim that chargers are a massive sink of energy - it says that it's an indication of a culture that's not energy-aware. http://www.inference.phy.cam.ac.uk/sustainable/images/BritainStandby.png http://www.inference.phy.cam.ac.uk/sustainable/images/Britai... Leaving mobile phone chargers plugged in and lights on were the most common energy-wasting habits.
- Hexstream 18y ago
  "Every little bit helps. 0.01% of energy is still a lot of energy..." Wrong. Spending time on spreading such an infinitesimal improvement has an opportunity cost. It's also lots of wasted effort and overhead on the part of anyone who will follow your advice.
- blackguardx 18y ago
  Your television consumes more power than your cell phone charger. Does anyone unplug that? Of course not.
  - jwilliams 18y ago
    I know a lot of people that turn their tv off (rather than standby). Why is it "of course not"? Why not "why wouldn't they"?
huhtenberg 18y ago
I am not a physicist, but this rant sounds pretty clueless to me. If I recall high school physics correctly, plugging an idle transformer into an AC outlet reduces available power of the current. This is because it affects a shift between I and U and thus causes the wattage (which is I x U integral over their period) to go down. It may also consume the energy if its assembly of a poor quality. This applies only to the traditional transformers, those with a coil inside. I am not sure what a modern phone charger has inside.
- jwilliams 18y ago
  This is generally called the power factor - if you have a purely inductive (your coil example) or capacitive load have a pf approaching 0. A purely resistive load is 1. Phone chargers and similar usually have pretty bad pf - but not because of the above, but because they are designed to take energy in short pulses (they call this a non-linear load). Energy isn't really consumed by this, but it does affect the way the distribution system is designed and operates (which may involve downstream energy waste).

8 points by nickb 18y ago

Every little bit helps. 0.01% of energy is still a lot of energy... Besides, what it does indicate is a culture around energy. Another problem is a proliferation of chargers. Instead of having one plugging in, people have two, or three, or a dozen. If there were better standards, you could have fewer, bigger, more efficient chargers. I'm not sure if this is addressed in USB3.0 (I'm pretty sure it's not), but there is an opportunity there to bring in a universal charger - that is smart and efficient at the same time.

bestes 18y ago
It creates a culture of nonsense. How can a message based on facts get through this noise?
- jwilliams 18y ago
  What's factually incorrect? When you have a charger plugged in with nothing connected, then 100% of the energy consumed goes to no useful work. Did you see the original BBC article? It also doesn't claim that chargers are a massive sink of energy - it says that it's an indication of a culture that's not energy-aware. http://www.inference.phy.cam.ac.uk/sustainable/images/BritainStandby.png http://www.inference.phy.cam.ac.uk/sustainable/images/Britai... Leaving mobile phone chargers plugged in and lights on were the most common energy-wasting habits.
Hexstream 18y ago
"Every little bit helps. 0.01% of energy is still a lot of energy..." Wrong. Spending time on spreading such an infinitesimal improvement has an opportunity cost. It's also lots of wasted effort and overhead on the part of anyone who will follow your advice.
blackguardx 18y ago
Your television consumes more power than your cell phone charger. Does anyone unplug that? Of course not.
- jwilliams 18y ago
  I know a lot of people that turn their tv off (rather than standby). Why is it "of course not"? Why not "why wouldn't they"?

huhtenberg 18y ago

I am not a physicist, but this rant sounds pretty clueless to me. If I recall high school physics correctly, plugging an idle transformer into an AC outlet reduces available power of the current. This is because it affects a shift between I and U and thus causes the wattage (which is I x U integral over their period) to go down. It may also consume the energy if its assembly of a poor quality. This applies only to the traditional transformers, those with a coil inside. I am not sure what a modern phone charger has inside.

jwilliams 18y ago
This is generally called the power factor - if you have a purely inductive (your coil example) or capacitive load have a pf approaching 0. A purely resistive load is 1. Phone chargers and similar usually have pretty bad pf - but not because of the above, but because they are designed to take energy in short pulses (they call this a non-linear load). Energy isn't really consumed by this, but it does affect the way the distribution system is designed and operates (which may involve downstream energy waste).