Wireless charging inefficiency

Wireless charging is great until an analysis of its efficiency reveals that this feature has a problem: much more energy is wasted.

The Wireless Power Consortium itself has long warned of the inefficiency of wireless charging systems, but a new study makes it clear that almost 50% more energy is used when charging the mobile with a wireless charger compared to using the charger with conventional cable.


Qi standard is the best we have right now, but it is still inefficient

Being able to transmit energy wirelessly is an old technological dream that has long come true. Wireless chargers that use techniques such as induction have long allowed us to charge our smartphones or watches and make our lives more comfortable, but they don't make it more efficient or cheaper.

The Wireless Power Consortium (WPC) already warned about it years ago. In a study to assess the efficiency of wireless charging, they confessed that measuring this parameter was quite difficult because, in the first place, there was no standardized methodology that allowed establishing how efficient (or inefficient) a wireless charging system was.

Precisely for this reason they set out to compare wireless charging technologies such as Rezence and Qi, which is currently the de facto standard in the industry. The first, Rezence, was a fantastic implementation for charging multiple devices at the same time on the same surface, but its cost and efficiency did not make it particularly advisable.

In that WPC study it was concluded that the efficiency should be calculated as a spatial average, and after comparing different chargers it was clear that the efficiency of these technologies was very poor in the case of Rezence (39.6%) and mediocre in the case of Qi (59.4%).



Wireless charging makes us spend almost 50% more energy

The Best Wireless Chargers for Your Android or iPhone | PCMag

The data has now been validated by a OneZero study comparing how much energy was needed to charge a Pixel 4 from 0 to 100% using various wireless chargers and confronting that average data with the energy necessary to charge it with its cable charger. .

The result was overwhelming: on average, wireless charging used 21.01 Wh, while wired charging used 14.26 Wh. That means that wireless charging used 47% more energy "for the convenience of not connecting a cable" than you actually do, but instead of connecting to the mobile you connect it to the wireless charging base, of course.

"In other words," concluded those responsible for the study, "the phone has to work harder, generate more heat and collect more energy when charging wirelessly to be able to fill a battery of the same size."

In that experiment, something that was also observed in the study of the Wireless Power Consortium became clear: the position in which you place the mobile in the wireless charger clearly affects the efficiency of charging.

ZENS Ultra Fast Wireless Charger Stand optimized for Apple iPhone

Despite the fact that phone power consumption is small, if we made every single phone wireless-charge capable with current technology, then we would be adding a 50% power inefficiency to every phone. Keeping in mind that there are currently more than 3000 million phones on the planet, we would get more than 6 billion dollars worth of power wasted, making it an environmental and social problem.