Flushing the toilet may soon generate an unexpected byproduct: renewable energy.

Researchers in South Korea have reportedly developed a method of harvesting electricity from the natural motion of water, ranging from drops of rain cascading down a window to a flushing toilet. The technology may eventually be used on surfaces outside of homes alongside solar and wind power-generating components.

“Using the energy harvesters based on this novel concept, we demonstrated the wide applicability toward natural water’s motions, such as rain, rivers, and even sea waves as well,” an abstract in Energy & Environmental Science reads. “We believe that they can substantially inspire for new energy harvesting technology form ambient energy sources.”

The key behind the technology is an adapted transducer generated by the research team at the Seoul National University and Korea Electronics Technology Institute. And while initial demonstrations have focused on small-scale applications, researchers believe the energy harvesters can “substantially inspire” new harvesting technologies from ambient energy sources.