Every time a toilet flushes, water rushes downwards thanks to gravity and an opportunity is lost. But with the HighDro system, those flushes can be converted into energy to power whatever building they're in.
Designed for large commercial buildings rather than homes, the HighDro system acts like a very small hydroelectric dam, turning the rushing water from long soil pipes into electricity using four blades turning a turbine. It's estimated to save $1,400 per year in electricity costs in a seven-story building. Not bad for something you were just flushing away without thinking about!