Engineers at Nokia have hatched a plan to for a system that’ll charge phones using nothing more than ambient electromagnetic radiation, or, as you and I might put it, electricity sucked from thin air. It sounds a little sci-fi at first, but it’s not: RFID tags are powered by electrical signals converted from electromagnetic waves emitted by a nearby sensor machine, which is exactly how this system is said to work. The thing is, the amount of electricity involved here is tiny , and Nokia’s system won’t even have a base station—it’ll draw from ambient electromagnetic waves, meaning Wi-Fi, cell towers and TV antennae. Nokia hopes to harvest about 50 milliwatts—not quite enough to sustain a phone, but enough to mitigate drain, and slowly charge a handset that’s been switched off.

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Nokia Developing Wireless, Accessory-Free Ambient Charging [Chargers]