What if you could power your MP3 player just by drinking a bottle of water? Welcome to the incredible world of pee power—or rather pee-powered batteries to be exact. Pee-powered batteries may sound a bit gross, but they may be the sustainable energy choice of the future. How come? Well. The power source, human urine is renewable, inexhaustible, and affordable. Plus, the batteries don’t cause pollution when they are discarded (regular batteries leak toxic chemicals into the landfill when they are tossed away!).

It almost sounds too good to be true doesn’t it? So how does this magical urine battery work? The secret to producing pee-power is a chemical reaction. When the urine contacts a chemical called copper chloride (copper is used to make pennies and chlorine is used to clean drinking water), a reaction occurs. This reaction creates electricity. Just a few drops of urine will generate the same amount of “juice” as your typical AA battery.

Urine batteries aren’t on the market yet, but when they are, what will they be used for? The first thing scientists hope to create is…a self-powered urine test! That’s actually a pretty cool idea. A patient pees in a little container and then the urine itself powers the battery that runs the test. Urine tests can tell doctor all about a patient’s health. If a patient has certain diseases, this can be seen by analyzing chemicals in the urine.

Hmm, this kind of gives a whole new meaning to the words “power pee!”