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Bill Bennett


Wireless charging:  Inefficient, bad for the planet

Wireless charging feels modern. But don’t let clever looking technology fool you. It doesn’t always work as well as promised and it could be terrible for the environment.

“…the slight convenience of juicing up your phone by plopping it onto a pad rather than plugging it in comes with a surprisingly robust environmental cost.

According to new calculations from OneZero and iFixit, wireless charging is drastically less efficient than charging with a cord, so much so that the widespread adoption of this technology could necessitate the construction of dozens of new power plants around the world.”

Source: Here’s Exactly How Inefficient Wireless Charging Is | Eric Ravenscraft | OneZero

Nokia claimed to have the world’s first wireless phone charging in 2012 with the Nokia Lumia 920.

At the time Nokia said its wireless charging was 90 percent efficient. That means the charger wasted 10 percent of energy, turning it into heat.

This doesn’t square with Eric Ravenscraft’s story at OneZero. He says:

“Charging the phone from completely dead to 100 percent using a cable took an average of 14.26 watt-hours (Wh). Using a wireless charger took, on average, 21.01 Wh.

That comes out to slightly more than 47 percent more energy for the convenience of not plugging in a cable. In other words, the phone had to work harder, generate more heat, and suck up more energy when wirelessly charging to fill the same size battery.”

Ravenscraft found how he positions the phone on the charging mat makes a huge difference. And he found it hard to line things up to get the best results.

Wireless charging hit and miss

Wireless charging can be hit and miss. There are mornings when I pick up my phone and discover that it didn’t charge overnight.

The phone only has to move a millimetre or two for that to happen. It is so sensitive that I can open a desk drawer or type on my keyboard and the phone moves away from a charging position.

In his story Ravenscraft reveals a wireless charger consumes a small amount of power when it isn’t charging a device.

All up, wireless chargers waste a lot of power. It may only be a tiny amount per person, per charger, but multiplied by millions of users around the world it adds up to environmental damage.

In my earlier story, I noted that wireless charging is handy, but plugging in a cable is hardly a big deal. You get almost no advantage for what, in aggregate, is a big environmental cost.



10 thoughts on “Wireless charging:  Inefficient, bad for the planet

  1. Thats an interesting point – it is far less efficient than a direct connection as induction leads to energy loss in the form of heat.. Some of the new fast charge wired technologies are pretty amazing too

  2. My phones charge port kept getting filled up with fluff and not working. I find wireless charger more reliable and it is certainly a lot less faffing. But good point all the same.

  3. I’m bemused by all the current talk about wireless charging. It’s hardly new. I was using it on my Google Nexus phone several years ago. Yes it was slow and yes, I had to make sure I placed my phone ‘just right’ on the pad, or it wouldn’t charge. But it was ok for those days when I had a phone that didn’t do fast charging. Back then, overnight charging was the only really practical regime for me and the wireless charging was fine for that.

    Then I bought a Moto phone that didn’t do wireless charging. I really didn’t miss wireless charging though, because the Moto had fast charging. Which I wouldn’t have wanted to run all night long.

    I now have an Oppo that does wireless charging, but my charging pad remains in the cupboard. I haven’t even investigated it. The battery always has a fair bit of juice in it the following morning and it’s a simple and quick matter to top it up with the fast charger.

    As I say, I’m bemused by all the current fuss about wireless charging. Fast charging is a far more useful technology.



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