7 Advantages + 5 Disadvantages Of Hydroelectric Energy

In light of global warming and climate change, renewable energy is being seen as a must in a changing world. Let’s look at the advantages and disadvantages of hydroelectric energy as an alternative form of power!


  1. Renewable,
  2. Emission free,
  3. Reliable,
  4. Affordable,
  5. Improves water quality,
  6. Employment,
  7. Flood protection, and
  8. Tourism.


  1. Negative impact on fish,
  2. Limited locations,
  3. Reservoir emissions,
  4. Drought risk, and
  5. High initial costs.

The advantages and disadvantages of hydroelectric energy are scientific while also being subject to socio-economic considerations.

These factors will be important when evaluating the advantages and disadvantages of utilizing hydroelectric energy.

Hydropower dam on a river

What Are The Advantages Of Hydroelectric Energy?

Hydroelectric energy as a source of alternative power provides numerous advantages over its contemporizes, both in the renewable and non-renewable sectors. Let’s look at eight common advantages now!

1. Hydroelectric Energy Is Renewable

To understand how hydroelectric power is renewable, a brief description of how a hydroelectric power plant works must be outlined.

Hydropower plants use lateral forces in the form of flowing water to turn turbines, which provides the kinetic energy needed to be converted into electricity.

The standard method of providing water to turbines is through the large dam walls that hold water reservoirs. These walls are fitted with sluice gates, which, when opened, allow water to flow downwards and across turbines before exiting the plant.

This means that the primary source of energy production for hydroelectric energy is water and the movement it creates.

This reliance on an infinite resource such as water and its infinite potential to provide kinetic energy make hydroelectric energy a renewable power source.

2. Hydroelectric Energy Is Emission Free

Because the movement of the turbines in a hydroelectric power plant is facilitated by the movement of a pollutant-free resource such as water, there is no combustion of materials that may emit harmful emissions.

Therefore, unlike non-renewable fossil fuels such as coal and oil, or renewable resources such as biomass and biofuels, there is no need for combustion to move the turbines and provide power.

The lack of combustion and harmful emissions is the primary difference between hydroelectric energy and its competitors in the energy sector.

While the method of producing electricity remains the same (i.e., kinetic energy conversion into electricity via turbines), these turbines use kinetic energy that makes hydroelectric power eco-friendly.

3. Hydroelectric Energy Is Reliable

Given that the water flow is predictable, constant, and capable of control through sluice gates, hydroelectric energy is considered a very reliable power source.

The ability to control the flow of water means that hydroelectric energy can adjust the electricity output generated. This allows varying levels of electricity to be generated in instances of either low or high energy demand.

The reliance on kinetic movement to produce energy via water means that hydroelectric energy is much safer than other forms of power generation, resulting in occupational and health hazards.


Examples are the chance of fires or similar disasters resulting from the combustion of fossil fuels or the risk of disasters arising from other energy sources such as a meltdown at a nuclear power plant or a spill when transporting oil.


Hydroelectric energy is also a domestic source of energy. This allows individual states to generate electricity locally while relying on international sources of power, nor the risk of market fluctuation affecting energy prices.


Hydroelectric energy is also seen as a reliable method of promoting other sources of renewable energy. This is because of technology such as pumped storage hydropower which allows for electricity storage.

Pumped storage hydropower means variables that make other forms of renewable energy unreliable, such as no sunshine for solar panels or no wind for wind turbines.

This stored hydroelectric energy can be used until more favorable conditions for other renewable energy arise. This balance between reliable and unreliable renewable energy working together is vital for longevity and buy-in.

4. Hydroelectric Energy Improves Water Quality

The reservoirs of hydroelectric power plants collect rainwater, which can be used for consumption or irrigation.

This storage of water and its necessity for the operation of hydroelectric energy is an inherent good. It protects water tables against depletion and reduces an area’s population to droughts.

The targeted release of water is a primary method by which hydroelectric energy dams can improve water quality, as this helps to improve environmental flows and temperatures.

Over and above sluice gate control and water storage, new technologies are being implemented to improve reservoirs’ water quality.

An exciting example of innovation is the upgrades to hydropower turbines which directly infuse dissolved oxygen into the water.

For a detailed discussion and visualization of these developments, please see the following link to the Office of Energy Efficiency & Renewable Energy’s article and video on the High Rock Dam hydropower facility:

5. Hydroelectric Energy Provides Employment

As of 2018, hydroelectric energy was the biggest producer of renewable energy in the United States of America, accounting for over 11% of all electricity generation. With hydroelectric power plants being found in each of the 50 states.

Due to the increased investment in renewable energy production and technologies, hydroelectric power, as the most popular form of renewable energy production, will need a large workforce to meet the demand for renewable electricity.

The workforce will require a diverse range of skills, in compliance with the following breakdown of jobs in the industry (as of 2019), the percentages are as follows of the 66 500 total jobs:

  1. 26.9% in the manufacturing sector,
  1. 26.3% in the utility sector,
  1. 18.4% in professional and business services,
  1. 16.1% in the construction sector,
  1. 11.8% in the trade and transportation sector, and
  1. 0.5% in other services.

The diverse skills needed and the large geographical areas hydroelectric power covers make it a key source of job creation in the growing renewable energy sector.

This is vitally important, as the large workforce in the non-renewable energy sector, which is projected to shrink as fossil fuels declines, needs to be redirected into other energy sectors for job security and energy demands.

6. Hydroelectric Energy Provides Flood Protection

One of the leading causes of flooding is an overflow of unmanned water systems, which in turn results in the potential for a multitude of waterways to exceed their carrying capacities.

The need for damming to create reservoirs to supply hydroelectric power plants means that in the event of overcapacity, this single large body of water can be easily monitored and controlled for flood management purposes.

Flood management has also evolved from a purely observational practice into a scientific and mathematical exercise with overwhelmingly positive results.

Using Brazil as an example, engineers use a matrix system whereby there exist amounts for waiting volumes in a reservoir and a volume in a reservoir for optimal energy production while not creating the risk of overcapacity and flooding.

These statistics are personalized for each dam and rely on mathematical models of recurrence time, flood probability, inflow period characteristics, operational constraints, and other factors.

7. Hydroelectric Energy Improves Tourism

The creation and maintenance of the reservoirs needed to feed water to hydroelectric power plants have a byproduct of offering recreational activities such as fishing, swimming, kayaking, white water rafting, and boating.

Most reservoirs must have public access to allow people to take advantage of these recreational activities, meaning that there is a reason to improve the infrastructure of rural areas to allow for ease of access.

This presents an opportunity for the reservoir itself and surrounding settlements to capitalize on tourists and hobbyists visiting the dam for recreational activities.

Recreational Facilities

The creation of recreational facilities and tourists to areas situated near reservoirs provides an income stream and method of job creation that is unique to hydroelectric energy as a source of renewable electricity generation.

Furthermore, dam walls often establish themselves as tourist attractions. The most notable in the United States of America is Hoover Dam, which crosses the Arizona-Nevada border and is near Vegas.

As the most visited dam globally, Hoover Dam is estimated to bring in over 7 million tourists a year!

For other examples of popular dams and why they are key tourist destinations globally, the following link to 4 Ever Green’s YouTube video on the “10 Most Beautiful Dams in the World showcases this:

What Are the Disadvantages Of Hydroelectric Energy?

While there are advantages of using hydroelectric energy as an alternative power source, there are socio-economic, environmental, and scientific disadvantages. Let’s look at five commonly observed disadvantages now.

1. Hydroelectric Energy Has A Negative Impact On Aquatic Life

Depending on the migration patterns of the fish found in the body of water being dammed for purposes of supplying water to hydroelectric power plants, this can have devastating results on fish stocks.

This is because damming may prevent fish from accessing breeding grounds, which results in an overall decline in the population. This has a knock-on effect, whereby other animals which rely on fish for food have their food source taken away.

Damming also results in a large body of water in a reservoir, meaning that riverside habitats that previously relied on the natural flow of water may dry up and disappear.


In contrast, yet equally as damaging, an influx of water may affect the biomes of naturally dry habitats. A prime example is the establishment of the Hoover Dam resulting in wetlands in the dry biomes of Nevada and Arizona.

The inclusion of large bodies of water means to dry biomes means that an entire ecosystem can be disrupted, as it leads to changes to fauna and flora, natural soil health, a change to the predator-prey cycle in an area, and increased infrastructure.

2. Hydroelectric Energy May Only Be Used In Limited Areas

While hydroelectric energy is a fantastic source of renewable energy, unlike its contemporizes of wind and solar, there are far fewer areas in which hydroelectric power plants can be established.

This is because of the delicate balancing act and conditions needed to establish a reservoir to supply a hydroelectric power plant.

Primary considerations include, but are not limited to: adequate water supply, adequate rainfall, close enough to settlements to easily supply electricity, in a biome that naturally supports a large body of water, and no detriment to other rivers.

Fortunately, while the United States of America has a multitude of biomes in each state that make hydroelectric energy viable throughout the country, drier countries such as Africa, The Middle – East, and South America have limited suitable areas.

3. Hydroelectric Energy Has Reservoir Emissions

Although hydroelectric energy itself is carbon emission-free and a clean source of energy, the creation of large reservoirs means an abundance of plant life that regularly exceeds the natural levels of the plant population in an area.

While this does have some benefits, the primary benefit of increased plant life, both aquatic and on the fringes of a reservoir, is that these plants decompose over time.

Once dead and successfully decomposed, these plant materials release significant quantities of harmful gases such as carbon and methane into the atmosphere, with both these gasses being the primary causes of global warming and climate change.

4. Hydroelectric Energy Is Negatively Affected By Droughts

The large bodies of waters housed in reservoirs needed to supply hydroelectric power plants have to remain consistent in order for reliable energy production to occur.

In the events of draughts, these water sources can dry up, meaning that hydroelectric power plants have no means by which to supply electricity.

Whereby the increase in temperatures caused by global warming increases the risk of droughts occurring.

5. Hydroelectric Energy Has High Initial Costs

Hydroelectric power plants are significantly more expensive to build than their fossil fuel counterparts due to the technology and high skill labor required to outfit them.

Furthermore, the dam infrastructure needed to build reservoirs for the purposes of water supply is high-cost other power plants do not face.

Fortunately, these high initial costs are often seen as a worthwhile exchange for producing cheap electricity after the plant’s completion and the reservoir’s dam.


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