Grinding stones powered by water wheels were developed in Greece in the third century BCE for milling grain and became the focus of urban settlement throughout Europe.
In da Vinci’s design, piped water falls onto and spins a horizontally placed impulse wheel which in turn spins a vertical shaft converted by gears into a horizontal driveshaft to transfer power. This configuration requires a much smaller water supply and is more efficient than older undershot and overshot waterwheels. Da Vinci’s design pre-figures water turbines developed in the 19th century for generating electrical power.
Micro-hydro technology was developed in Australia in the 1990s to generate electricity from very small water flows for remote Pacific island communities and has been adopted by many rural households in the move towards sustainable electricity generation.
Francis type hydro-electric turbine
Photo: emel82 / Shutterstock.com
Photo: Audrius Meskauskas