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Hydroelectric energy

Hydroelectric energy

Cromford’s eighteenth century water wheel in England and China’s impressive Three Gorges Dam are subtly connected. Even though they hardly look similar, they’re in fact two crafts of the same human skill: harnessing energy from earth’s blue gold, water.

About hydroelectric energy

Water, humankind’s first power

Water is much more than the basis of life and an essential part of our food chain and hygiene but also, one of mankind’s first forays in harnessing energy through natural resources, hence, hydroelectric power. Based on the 2019 report by the International Renewable Energy Agency (IRENA), total capacity from the world’s hydroelectric power plant amounts to 1,172 GW: about 50% of total renewable power output.

Even if hydroelectric power is the dean of renewable power sources, this hasn’t stopped R&D from increasing its efficiency. Thanks to currently available technology, 90% of water is now transformed in electricity, delivering a three-fold increase in efficiency compared to traditional power sources.

A low carbon footprint and high efficiency are the factors that concur in delivering excellent performance: along the world’s biggest renewable power plants, the top five in this ranking are powered by water. 

History of hydroelectric energy

Water and energy. A two thousand year-old connection

How hydroelectric energy works

Water and gravity, a perfect mix

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Hydroelectric power can count on two simple yet formidable allies: water and gravity. All types of hydroelectric power plants leverage on gravity to accelerate its flow and unleash the power carried by its kinetic energy.

In order to harness electricity from water, a reservoir is needed to store its potential energy, usually in the form of an artificial lake created by a dam located upstream.

A series of giant water mains allow water to forcefully cascade downstream, where the bulk of the power plant machinery is located. Thanks to the drop created by the water mains, water increases its speed until it makes the turbine blades spin, which in turn are mechanically connected to a generator. This is the moment for electricity to run through an alternator that lowers the intensity of the current while increasing its voltage to streamline its subsequent feeding in the power grid.

Hydroelectric basins

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Power plant

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Strong points of hydroelectric energy

Long-lasting and efficient energy

Flexibility and efficiency

Output from hydro power plants can be quickly adapted to suit new supply-based needs, while its kw/hour costs are very competitive. 


The service life of an hydroelectric power plant can potentially span a century: ample time to generate sustainable energy aplenty. 

Less CO2

Hydroelectric power plants are carbon neutral, representing a great advantage for both the environment and humankind’s wellbeing. 

Did you know?

A waterfall made from 24 million light bulbs

The name says it all: Niagara Falls. Located at the American-Canadian border, they’re one of the world’s most valued and visited natural landmarks. Far from being the tallest, what makes them so spectacular is the hugely vast waterfront and its impressive flow rate: roughly 168 thousand cubic meters a minute during an overflow. A natural resource with an extraordinary renewable power potential.

Works on an hydroelectric power plant started out by the end of the nineteenth century, carefully respecting the beauty and relevance of such an iconic natural landmark. Niagara Falls currently see two main power plants, namely, the Robert Moses Niagara Power Plant and the Lewiston Pump-Generating Plant. The whole hydroelectric complex generates energy worth roughly 2.4 million kilowatts. That’s enough energy to light up 24 million 100-watt light bulbs at once.

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