Xiaomi is working on wireless charging with 80W – Tablets and phones – News

The energy that a transmitter sends out spreads like a sphere around the transmitter. If you have an 80W transmitter, you can receive 80W when you sit against the transmitter. At a distance of a meter, the field strength is only 0.63 mW / cm². This is completely nothing compared to the power of the transmitter.

To heat up water you need 4.3 joules per degree per gram. That 0.63 mW is 0.00063 joules per second. So you need 1572 seconds to heat up one gram of water one degree.

I hereby ignore three very important things. Firstly, the ‘detail’ that the frequency at which the coils work can do nothing with your body, and your popcorn cannot be heated with this energy. 2.4 Ghz works to heat up your popcorn, 2.3 Ghz and 2.5 Ghz do nothing for this, not even a little bit. The frequency of these chargers is (far) below 1 Mhz, so 0.001 Ghz with which your popcorn will not heat up, even with a 100 kW source.

A second point is perhaps more important; the 80W transmitter that only transmits the energy when there is actually a telephone on the transmitter. It is therefore not the case that the charger / transmitter is continuously sending 80W; it only does this if it has a telephone on it. This phone absorbs just about all the energy as it uses it to charge.

The third point is the legal maximum radiation that a device may emit. This is laid down in the CE legislation with which devices must comply. Such a charger is made in such a way that it meets these requirements. So whatever the sender sends goes to the receiver, and doesn’t leak out into the room.

So summary:
Due to the CE requirements, there is hardly any radiation.
The radiation from the charger only goes to the phone, and not into the room / room.
You cannot heat popcorn with what does leak out.
And if you ignore all points, there is still too little energy to heat up popcorn

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