How effective it is, in fact, to use wireless charging and why it matters

As the wireless charging feature begins to be found on more and more smartphone models, including Apple, how this technology works and its inefficiencies begin to matter unexpectedly, raising the question of whether charging mobile phones contributes decisively to global warming.

At first glance, it seems unlikely that a battery-powered smartphone will contribute to global warming through the energy consumed during the charging process. But what if we talk about 100 million mobile phones, or 1 billion? But if we take into account the fact that more than half of the energy consumed for charging does not actually reach the battery, but is lost in the form of heat due to the inefficiencies of the transfer process.

Obviously, placing the phone on a charging cradle is much more convenient than physically connecting a cable, which eventually remains abandoned on the desk. But what does, in fact, involve the wireless transfer of energy to the battery of a smartphone.

Although it is not immediately obvious why, there is a good reason why households do not have a wireless electricity speaker to power all our gadgets without ever reaching for a cable or extension cord. This is because the technology once invented by Nikola Tesla is far from efficient, much of the energy emitted in the ether being absorbed and converted into heat by other electrically conductive elements such as building reinforcement, dissipated in the ether, or even wasted by the emitting device.

In the case of smartphones, however, we are talking about much lower transmission powers, which means that the losses should be just as small. However, this is not the case.

Wireless charging, convenient solution and that’s it

The first problem we encounter when using wireless charging systems is that the charging speed is strongly dependent on the accuracy with which we place the smartphone perfectly centered on the charging cradle, any deviation reducing the power supply mentioned in the list of specifications.

The problem is that the energy transmitted wirelessly between the power supply and the mobile phone is not fully captured, the experiments showing that on average 47% of the energy used is wasted, being converted directly into heat. Thus, if a power of 14.26 Whr is delivered to achieve a similar charging level via the USB-C cable, 21.04 Whr is needed in wireless mode, after taking into account the inefficiencies of the power supply technology. In the least favorable scenario, the careless alignment of the phone on the wireless charging cradle can increase even 80% of the energy consumed when charging, compared to using the USB-C cable.

Reassessing the experiment to take into account the 3.5 billion mobile phones charged daily in the world, the use of wireless charging technologies would waste a huge amount of energy, effectively doubling the energy consumption currently attributed to charging smartphones.