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Wireless charging may be inefficient, but it's only a catastrophe if you ignore the alternatives

Wireless chargers
Wireless chargers (Image credit: Ara Wagoner / Android Central)

There's a great article on OneZero from Eric Ravenscraft about how wireless charging's low efficiency wastes so much electricity that its wide adoption could mean dozens of new power plants will need to be built across the globe. It's a really interesting read and highlights the thing that many people already suspected: wireless charging wastes a lot of energy compared to plugging something into a charger.

Once you move past the hyperbolic headline and get to the meat of the matter you'll see just how inefficient wireless charging really is. Every time you set your phone or something like a pair of wireless earbuds on a charging pad, you're using about 50% more energy to charge them compared to using a cable. Part of the reason is that it can be tough to align electromagnetic coils properly to transfer the full amount of energy they are capable of, but part of it is simply because wireless charging just uses more power.

It's one of the design flaws, if you will, of inductive charging. You're sending power through coils that are aligned in a way to oscillate and create a magnetic field. If you know any basic electricity theory, that's very close to how a generator "creates" electricity when it builds a magnetic field around a conductor. The difference is that a much more conservative way to charge something like a phone battery exists, and that's just plugging it into a cable that's attached to a charger. You know, like the good ol' days.

Wireless charging wastes power because of its design.

We're not going to go deep into electrical theory and talk about how all of this works or ways that energy-producing plants could become more efficient. What we're concerned with is the things we do and how any action from us could contribute to what Ravenscraft calls a problem.

Pixel Stand

Source: Android Central (Image credit: Source: Android Central)

Whether you agree that this is a problem or not, it's not our problem to solve. Any discussion should start right there. Wireless charging isn't becoming popular because of its efficiency, it's becoming popular because of its convenience. I think that the wasted energy from conductive charging is something that needs to be looked at but not by consumers.

Consumers aren't the right group to investigate how to build high-efficiency chargers.

Companies that design chargers, products that use them, and bodies that set standards should be investigating how to build equipment that doesn't waste power. And they are. As consumers, all we need to understand is that using a wireless charger could cost us a few dollars more each year from higher utility bills and decide if the convenience is worthwhile.

That convenience factor goes beyond not having to plug your phone in, too. Repeatedly plugging in a charging cable causes wear and tear on both the cable and whatever it is being plugged into. Many of us have seen a phone where you have to position the cable just right so that it can charge and that's because wear has made the connection less solid. This is exactly why I use wireless charging whenever I can — replacing USB ports in phones is tricky if you know what you're doing and expensive if you don't.

Cables aren't that expensive. That's because they aren't built to be tough. A cable is a weak spot compared to a charger or a phone and I think almost all of us have a handful of them stashed somewhere. The sun will rot them while in your car, unplugging them out will cause the cable to pull out of the connector, and repeated contact with a socket will misshape the metal ends over time.

Galaxy S20 Charging

Source: Android Central (Image credit: Source: Android Central)

Charging bricks will last a lot longer, but they too can go bad before a phone does. They create heat which causes both internal parts to degrade as well as making the plastic shell brittle — sometimes brittle enough to crack. You'll have these problems whether you're using them to directly charge a phone or if you're using them to power a wireless charger. But problems with the connection no longer making contact can also happen when you're repeatedly plugging and unplugging a cable.

These "problems" are minor. Nobody complains that they used a cable so much it needed to be replaced, and even a very high-quality cable isn't expensive compared to the device it's topping up. But like the wasted energy of wireless charging, scaling up the issue to include billions of users means it is a real problem all the same.

To do a fair study, the costs of making and selling replacement equipment needs to be factored.

Nobody has done a study about how much electricity is used to manufacture and sell replacement cables, but I'm willing to bet it's at least as much as wireless chargers can waste. When you add in the cost of repairing or replacing phones because of a failed charging port, I'm certain it's more. These costs could all disappear if every phone used wireless charging as the only way to charge the battery.

I hate to make light of anyone's work, and that's not what I am doing. The OneZero piece did a great job of parsing through data to reach his conclusion, and finding an angle to make your writing stand out from the rest of the internet is tough. There are a lot of discussions to be had about wireless charging, especially if the tech ever branches out from consumer electronics to things like home appliances or automobiles. But that's a discussion for engineers to have, not consumers.

What we should be concerned about is that manufacturers try hard to provide us with the options we want to see at a price that reflects their true value. If you like wireless charging, buy a phone that supports it along with a good wireless charger and ignore the problems electrical engineers need to care about.

Jerry Hildenbrand
Jerry Hildenbrand

Jerry is an amateur woodworker and struggling shade tree mechanic. There's nothing he can't take apart, but many things he can't reassemble. You'll find him writing and speaking his loud opinion on Android Central and occasionally on Twitter.

26 Comments
  • Seems like an overblown issue since the amount electricity it takes to charge a phone is insignificant on your monthly bill, wireless or not.
  • On a national or global scale though, it adds up. Especially when considered as a symptom of more general apathy.
  • Evelyn from The Incredibles 2: "It may be crap, but it's convenient!"
  • tell you what, turn off your lights in any room and tell me how many have many lights do you see on different devices, surge protectors and more that cannot be turned off unless you unplug it? now that is a waste and on the national scale it is hundreds if not thousands of times more waste than wireless charging.
  • And the amount of time we're wasting on articles like this also adds up. What a waste of an article
  • Correct, the real question is why people seem to be in love with a solution that provides very few actual benefits and has significant draw backs. The "cool factor" isn't even that cool.
  • Not about being cool, it is about convenience. I was all the time putting the phone on the bar as soon as I get home and forgetting to plug it in. I placed a wireless charger where I have been placing the phone and not a dead phone since.
  • I got 46% power loss in my research, so the basic numbers are pretty much on target. I think the article does exaggerate the issue a bit because not everybody is going to be using wireless charging, even if it is available on all devices. There are talks of port-less phones, but you are not going to see that on budget or most midrange phones. But despite wasting half the power, there's a bigger issue: Multiple chargers. People have a charger on the night stand, in the living room, in the kitchen, bathroom, den, and garage too. I don't fault people for that; it's convenient. But the thing is that the multitude of chargers laying about, sometimes to support one or two devices, all continue to use power 24/7 even when not in use. Nobody's measured that.
  • Based on the numbers I see for the standby mode on the wireless chargers, it's something in the neighborhood of about 1 charge cycle worth of power per year.
  • I couldn't care less....
  • You're the problem with society.
  • You're the problem with society
  • No I'm not, the silly climate mongos are...
  • This is a dumb article yes wireless charging is less efficient than wired, however I'm sure over time the tech will get better, it always does. Ppls cars are even more inefficient in turning energy to usable energy however no one is saying stop driving cars but rather looking for more efficient technologies.
  • To be fair, plenty of people say stop driving cars. They're just often ignored.
  • Usually those people just don’t need a car and can’t put themselves in the shoes of someone who really does... A bit selfish and easy to say that
  • Honestly, I've had phones that have had wireless charging in and off for years and I could care less about it. It's saves a fraction of a second to charge the phone, hearts up the battery and most people who use wireless charging still use wired charging for when they are out and about, so it doesn't really save any cables. When it comes to the cables and ports themselves. I'm not super careful it anything but I've never broke a USB port and only once it twice abused a cable so much that it dies. So for now I'll just save the electricity thank you very much. One day, much like the headphone jack they'll probably do away with the USB power port and I'll adjust to using wireless all the time. But I'm in no rush. I just don't see the appeal now.
  • not wasting enough to reconsider the convenience of using a wilreless charger.
  • I've been charging my phones wirelessly on the nightstand for several years. It's convenient, reduces wear on the port, and easier on the battery than the factory rapid charger (slower, less heat). My current LG V60 has a big 5000 mAh battery, and never needs topping up during the day. I only plug in a cable during the infrequent times I need Android Auto (because my car requires it).
  • I have no use for wireless charging. I have never had a port go bad on a device. It is a feature that I just don't care about and prefer not to have.
  • I really don't see it as much of an issue - over 90% of the electricity generation in Scotland is now from wholly renewable sources (and it keeps going up), so it's no big deal to use a little bit more power! I've just started using wireless charging again (last used it 5y ago) and it's fantastic!
  • First of all the headline sucks.. secondly, "dozens of new power plants" is a joke right? Wireless charger uses 10 extra watts for 1.5h . That's 15 watts per day, 0.5 killawatt hours per month... Adds about 3 cents to your monthly bill. Your TV in 5 minutes (each day) will use more power
  • Not to be a jerk but if you are saying wireless wastes 0.5kwh, then in 5 minutes you are saying the TV consumes 6000w 12*0.5. That is one heck of a TV. Fwiw most TV are under 100w now.
  • Microsoft should make their Surface Connect port an open standard. Magnetic attachment, loads of power, multiple data connections, audio, video, and a reversible design, all in a tiny connector that would fit on any device except maybe a watch, and still allow ipx rating. This should have b
  • Microsoft should make their Surface Connect port an open standard. Magnetic attachment, zero insertion force, loads of power, multiple data connections, audio, video, and a reversible design, all in a tiny connector that would fit on any device except maybe a watch, and still allow an ipx rating. USB type c has nothing on this.
  • The headline is like me saying 'I'd be the greatest footballer in the world if there were no other footballers around'. It would be true in a static sense, but it wouldn't make me better at football to begin with. Wireless charging is a useful feature to have. I've been using it since I dropped £60 on a Palm touchstone for my Pre back in 2010 but its only useful if you dont have to think about it. I have a bunch of Ikea lamps with Qi chargers built in around my home so I can just plonk my phone down anywhere and the lamp would already be using electricity so the charging pad is a bonus, but having to buy plates for every location you might want to set down your phone is inconvenient.