Hydro or water energy is the conversion of hydropower into electricity. Hydropower refers to the force of water flow that turns turbines and powers generators, which then store the electricity into power grids for mass consumption.  The hydropower process is a clean renewable energy resource because the water cycle occurs naturally. The movement of water throughout Earth’s systems is called the hydrologic cycle. This cycle is influenced by solar energy like other clean energy sources. This is because the amount of heat from the sun causes the water to change in the atmosphere, making it solid, liquid, or gas. 
There are different types of designs for creating hydro energy and they include impoundment, diversion, and pumped storage. The most used method to generate hydro energy is the impoundment design, which functions within a dam and reservoir. The impoundment design controls the amount of water that runs through an opening in the dam and then passes by and spins turbines connected to a generator. Diversion designs produce hydro energy by allowing parts of a flowing body of water to channel through a funnel filled with turbines and then continue on a natural path. The final design called pumped storage operates by using two reservoirs, one at a high elevation and one at a low elevation. This type of facility stores electricity during low demand periods by pumping water to the high elevation reservoir. When there is a high energy demand, the water from uphill is released down to the low elevation reservoir and moves through turbines connected to a generator. 
Hydro energy has historically been used as far back as 202 B.C in China. Hydro energy was used to crush grains and even played a role in the production of paper. The first large scale use of hydro energy was in 1771 England in Richard Arkwright’s cotton spinning factory. This technological advancement encouraged Arkwright to later begin using steam engines to enhance his business. Spinning turbines that served as precursors to those used in hydro energy mechanisms today first appeared in 1827 thanks to a French engineer named Benoit Fourneyron. The turbine system was later refined for efficiently creating hydro energy by James Francis in the mid 19th century. Francis’ design is still popular today. Over the next couple of decades inventors and innovators created modified versions of hydropower turbines, each capable of effectively generating hydro energy.
Hydro energy was first harnessed to generate electricity in 1878 England. The energy was used to light a lamp in the Cragside country house. A few years later, many hydropower factories were built throughout the United States to deliver light to citizens and power mills. By the end of the 19th century the hydro energy following spread worldwide with plants being created in Germany, Australia, and China. The largest hydropower producer today is China’s Three Gorges Dam producing 22,500 megawatts of electricity. Hydro energy is beneficial economically as well resourcefully. Brazil for example, used water to generate 80% of electricity in 2011 and because of this outstanding production raised the value of its gross domestic product (GDP).