How Do You Charge For Wireless Power?
The thing that stopped Nikola Tesla from developing his experimental wireless power system further wasn't a technology issue; it was that the power companies didn't know how they could charge for power if you could just put a spike in the ground to receive it. That's not a problem if I have to be close enough to touch the power transmitter, or at least close enough that you can see I'm using power. The same data transmission that makes sure devices get the right power means wireless power that works at a longer range can deal with the problems of encryption and pairing. Because you can send data, you can shut off power transmission until the coupled device receiving it has responded with the correct account code. Want to unlock an airport phone charging surface while you wait for your plane? There'll be an app for that - or you might just send a text message that unlocks access.
David Graham of PowerBeam is planning a second-generation device he thinks will be a big hit in Asian markets like Korea where people travel more by train than car. He describes a charger that looks like a bulb; it does give out light but it also sweeps a laser beam across the room (say a coffee bar) until it finds a device sitting on a table waiting to be charged. Your phone could use Bluetooth to broadcast what power it needs and how to bill you and get a charge while you drink your coffee. For small amounts of power, wireless power might be like Wi-Fi: free to attract customers.