What is the earliest use of tidal energy?
The earliest evidence seems to date back to about 900AD, but there could be older efforts lost in time. Early tidal power plants captured the water from a rising tide and held it back till the tide went out. The water was then used to turn a paddlewheel to grind grain into flour. There was a plant in Hayle, in England, where the tidal water was used to dredge a shipping channel free from mud.
