Renewable energy, greentech and cleantech are terms that we have heard a lot in recent years. But there in nothing new about the concept of harnessing natural energy sources either as a means of production or simply to make life more comfortable.
An early form of renewable energy that most people are familiar with is windmills that were used for milling grain to produce flour. Windmills can also be adapted to other mechanical uses including the pumping of water. The earliest known example of the energy of the wind being used to power machinery was the Greek engineer Heron of Alexandria.
The ancient Greeks are also credited with being early adopters of Hydro power. Waterwheels were used to capture the power of flowing water in a very similar to modern hydroelectric power plants. Waterwheels that milled flour, pulped wood for paper making, and pounded fiber in the manufacture of cloth were a key component of the industrial revolution.
However the earliest use of renewable energy may go to the Chinese engineers of the Qin dynasty in the 3rd century B.C. who used geothermal energy to heat their spa. The ancient Romans were also prolific users of geothermal energy using it to both heat public baths and for underfloor heating.
