Hydroelectric power: All there is to know about Hydroelectric energy

Hydroelectric Power

As we’ve mentioned before, renewable energy is a hot topic and is likely to rise in stock as manufacturers seek to lower carbon emissions and seek more sustainable, cleaner forms of energy production, such as solar energy, wind power, or hydroelectric power.

As reports surface of Scottish Power’s plans to expand “pumped storage” hydroelectric power in Scotland, we’ve produced this ‘all there is to know’ article, to look at hydroelectric power in more detail.

What is hydroelectric power?

Hydroelectric power is the production of electrical power by harnessing the gravitational force of flowing or falling water. It accounts for approximately 16 percent of global electricity generation, making it the most prevalent form of renewable energy. This growing field is expected to produce incremental increases of output - amounting to more than three percent annually - for the next quarter of a century.

How do you create hydroelectric energy?

Hydroelectric power

There are four recognised methods of generating hydropower or hydroelectric energy:

  • Conventional dams, which use the water’s outflow to drive a turbine or generator
  • Pumped storage, which pumps water into a higher reservoir for release during times of higher demand
  • Run-of-the-river, where reservoirs are not a viable option
  • Tidal, making use of the daily ebbs and flows of the sea.

 Hydroelectric dam

How widespread is hydroelectric power?

It is estimated that hydropower is now generated in 150 countries globally, with the Asia-Pacific region said to produce a staggering 32 percent of global hydropower in 2010. Perhaps surprisingly, China is the biggest exponent of hydroelectricity, with 721 terawatt-hours of production in 2010, amounting to 17 percent of domestic electricity use.

Is hydroelectric power widespread?

How expensive is it to create hydroelectric energy?

The cost of hydroelectricity is reportedly relatively low, ranking highly as a source of cost efficient sustainable energy. The average cost of electricity from a hydro plant larger than 10 megawatts is 3 to 5 U.S. cents per kilowatt-hour, according to the Worldwatch Institute.

What equipment do hydroelectric power plants use?

According to ThomasNet.com: “A generator is the heart of a hydropower plant, and it is necessary to understand how it functions in order to grasp the other principles of hydroelectric energy. In a generator, electromagnetic charge is created by applying direct current to copper wiring attached to an assembly of magnetic steel. These steel field poles are positioned on the edge of a rotor, which is linked to a rotating turbine.

“As the rotor moves the field poles around the conductors embedded within an external wheel, electricity flows and generates voltage at the generator’s output centers. The generator is usually housed within a protective structure, and its stored energy can be fed into power lines.”

Where are hydroelectric power plants?

There are now three hydroelectricity plants larger than 10 GW: the Three Gorges Dam in China (22.5 GW), Itaipu Dam across the Brazil/Paraguay border (14 GW), and Guri Dam in Venezuela (10.2 GW).

The Three Gorges Dam - China

Three gorges dam in china


The Itaipu Dam - Brazil

Itaipu dam in brazil

Large-scale hydroelectric power stations are seen as the largest power producing facilities in the world, with some hydroelectric facilities capable of generating more than double the installed capacities of the current largest nuclear power stations.

Video: Learn more by watching this video on the the Three Gorges Dam in China <h4>

The advantages of hydroelectric power

Hydroelectric power plants have the great advantage that they don’t burn fuel, which means lower operational costs and of course less pollution. There is minimal waste disposal to worry about (unlike nuclear for example) and after the initial setup costs, the constant supply of rainfall and flowing water provides a highly reliable, sustainable and cost efficient means of energy production.

The pitfalls of hydroelectric power

Damming obviously interrupts the flow of rivers and can potentially imbalance the surrounding ecosystems. From another perspective, building large dams and reservoirs can often involve large-scale displacement people and wildlife. In 2000, the World Commission on Dams estimated that dams had physically displaced 40-80 million people worldwide.

It’s also worth noting that reservoirs in tropical areas are known to produce substantial amounts of methane, a greenhouse gas, from stagnating plant material (though far less in temperate boreal conditions). And climate change could alter rainfall patterns and river flow-rates, even with a modest increase in temperatures.

So there you have it, a brief guide to hydroelectric power. Is this the answer to our growing global demands for electricity, particularly in developing nations? Or are there more efficient methods we should consider instead?

Let us know your thoughts.

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