The E-Kaia device claims to be able to harvest electricity released into soil by small plants. Here's a Daily Mail article describing it.
And because not all of the electrons are needed, harvesting them doesn't impact the plant.
According to E-Kaia, the technology can output up to five volts at around 600 milliamps, and this can charge a phone in around an hour and a half.
Is this possible - does it actually charge in an hour and a half, and can electricity actually be produced from a pot plant?