The UK's biggest music festival Glastonbury is trying out some pretty special toilets this year, which could help you charge your smartphone.
A group of scientists have invented a gadget which turns pee into electricity.
They hope it could be used in some poorer countries, as a way to create clean and renewable energy.
The system was developed by scientists at the Bristol Bioenergy Centre (BBiC) in the Bristol Robotics Laboratory at the University of the West of England (UWE Bristol).
The invention will be tried out this week on festival-goers at the Glastonbury music festival in Somerset.
But, how does it work?
Urine, or wee is fed into a special machine called a microbial fuel cell, which contains a type of bacteria.
These tiny bacteria break down the wee and create electrons.
These electrons are then forced through an electronic circuit, creating a flow of electricity.
This electricity can then be used to power all sorts of things, including your phone!