19 Advantages and Disadvantages of Hydroelectric Energy

Hydroelectric energy is one of the oldest and most affordable methods of producing power on our planet today. These facts make it a competitive resource as a renewable option when compared to the use of fossil fuels like crude oil or natural gas.

Four categories of hydroelectric energy are available today.

  • Pumped-storage hydroelectric power.
  • Conventional approaches, such as dams.
  • Offshore marine energy collection, such as tidal energy.
  • Water movement power, like river motion.

When a hydroelectric power plant is completed, the facility doesn’t produce any direct waste during operations. That means it has a lower output of greenhouse gas emissions when looking at the long-term impacts on the environment.

The advantages and disadvantages of hydroelectric energy show us that it accounts for one-sixth of the world’s electricity production today. Over 30 gigawatts of capacity were put into operation alone in 2016. China, Brazil, Canada, India, Russia, Japan, and the United States account for over 60% of the installed capacity of this resource.

List of the Advantages of Hydroelectric Energy

1. Hydroelectric energy is a renewable resource we can use.
We consider hydroelectric energy to be renewable because it uses existing water resources to generate electricity. If we didn’t have any water, then technically this power-generating opportunity would go away, but then humanity would not likely survive either. The natural water cycle replenishes our supplies through rainfall and various methods, meaning the odds that we’d ever run out are infinitesimal.

The amount of hydroelectricity that we can produce regionally is dependent on drought and seasonal changes, but the outcomes are still predictable.

2. It is clean and safe to use hydroelectric energy for our needs.
Hydroelectric power is a green, environmentally friendly energy resource that we can use safely without worrying about its impact around us. Although it requires fossil fuels to construct the initial collection resources, the lack of fuel needed to produce power means that zero greenhouse gases get released into the environment. The risk of toxins being introduced into the atmosphere is very minimal.

This benefit isn’t possible when looking at energy resources like biomass or fossil fuels. Nuclear power is equally clean from an emissions standpoint, but you don’t need to worry about radiation when you build a dam. That’s why this option features prominently as a global energy resource.

3. Hydroelectricity is a flexible resource for us to use.
We can scale hydroelectric plants up or down rapidly to ensure that changing energy demands get met effectively. This flexibility isn’t available in other production plants, especially in the renewables sector. The startup time for hydro turbines is much shorter than it is for steam-based for gas turbines, which means we have immediate access to new resources when needed.

This advantage of hydroelectricity allows us to use it as a backup for generators that work on fossil fuels. It works with our existing energy infrastructure so that supplies can travel effectively without making another massive investment to access the power we need as a society.

4. It is a cost-competitive energy resource.
Although hydroelectricity plants have a significant upfront building cost, the power that we can use after the facility goes live is still a cost-competitive energy resource. This advantage is possible because of the lower maintenance and operation costs that are only available with this option. There are fewer parts in most facilities when compared to other energy generation facilities, which means minimal replacement expenses exist.

Many of the facilities that we build are designed for long-term use, which means their capability of producing power can be upwards of 100 years. The average facility today has been in operation for 64 years, and this technology accounts for 99% of the current operating capacity that was built before 1930.

5. Hydroelectricity is suitable for industrial applications.
The majority of the hydroelectricity installations work to support public networks for residential use. Because of the advantages that this renewable resource offers, some facilities are constructed to serve specific industrial enterprises where large amounts of electricity are needed. You’ll see dedicated plants built specifically for aluminum electrolytic facilities because of this specific benefit.

The technology that fuels hydroelectricity is simple and easy to understand. As long as there is water and a turbine that spins, then producing electricity is possible. That means we have the energy to use for industrial purposes that won’t tap into residential resources

6. The facilities can serve other societal purposes that generate revenues.
Most hydroelectric facilities take the traditional form of a dam on a river. That means a reservoir will form behind it as water levels build, creating a tourist attraction in its own right. These lakes can be used for water sports and also leisure activities like fishing and swimming. Most regions use the water from these projects for aquaculture or irrigation needs to support other industries.

Hoover Dam spans the border of Arizona and Nevada in its location about 30 miles southeast of Las Vegas. It’s the most-visited facility of its type in the world, hosting 7 million visitors each year. About 1 million people tour the hydroelectricity plant in the dam each year.

7. Hydroelectricity can promote remote community development.
Hydroelectric facilities can go anywhere that moving water exists. That means many of the world’s rural communities, which often have an economy based on agriculture, can receive energy supports with this technology. The installations attract new industries, opportunities for commerce, and modern infrastructure that facilitate connections with the rest of the world.

This advantage can lead to improvements in local education and healthcare resources. It can promote better opportunities for trade or create more choices at the retail level. That means hydroelectricity can improve the quality of life for the people it touches, no matter what stage of development happens to exist.

8. We can access hydroelectricity at all hours of the day.
Wind and solar energy offer natural limitations that force us to store the electricity we can generate to use during off periods. Hydroelectricity is always available because water is always flowing. That means we can use it day or night without worrying about its presence. The only other form of renewable energy that can offer this advantage is geothermal.

There are limitations that must come under consideration when looking at this benefit. Places with low water levels may not be able to supply enough electricity, while drought or changing climate conditions could reduce availability in areas where energy was once plentiful.

9. Hydroelectricity is reliable.
Hydroelectric plants create few fluctuations with regard to the quality and levels of electricity that gets created by their turbines. It is useful as a baseload energy resource because of this advantage. Assuming that there is water remaining in the magazines of the facility, then electricity will get generated. Although limited reservoirs could prevent access to enough water in some situations, we generally build our capacity in areas where even long-term drought won’t entirely remove our access to this resource.

List of the Disadvantages of Hydroelectric Energy

1. Hydroelectricity comes with a significant capital cost.
The cost to build a hydroelectric power plant is significant. These expensive projects have numerous logistical challenges to manage, even if the facility is being built on a river to take advantage of its motion. When Hoover Dam was built, it took five years and $49 million to complete the project. The schedule was finished two years in advance, but the cost in today’s money would have been over $750 million today.

Even when we look at other energy production methods with hydroelectricity, the costs are still high. The Cobscook Bay Tidal Energy Project had a cost of $21 million for only three turbines. The Sihwa tidal power station in South Korea is the largest in the world, and its 254-megawatt capacity cost $298 million to complete in 2011.

2. The risk of failure still exists for hydroelectricity facilities.
The traditional approach to hydroelectricity involves the use of a dam holding back a large volume of water. When the facility goes through a substandard construction process, experiences damage from a natural disaster or some other form of compromise occurs, then the reservoir must go downstream. It has no other option. That means the influx to the rivers can be immediately dangerous to settlements and existing infrastructure.

When Typhoon Nina struck the Banqiao Reservoir Dam in 1974, the excessive rainfall would eventually cause the dam to give way. The failure resulted in the deaths of 171,000 people while huge losses to property were recorded. Millions were displaced until the dam was rebuilt.

3. Hydroelectric facilities can still produce methane.
Although we consider hydroelectricity to be a clean form of energy production, it can also encourage higher levels of methane production over time. Researchers have noted that the plant materials in the flooded areas will begin to rot, even if it is underneath a significant volume of water. As the decomposition process continues, the levels of methane that get released into the reservoir can eventually make its way up to the atmosphere. This process takes longer to have an impact on the environment, but it still creates an increase in pollution levels that can be disadvantageous for some communities.

4. The presence of hydroelectric facilities might encourage drought.
Local droughts can occur when a hydroelectric facility gets built because it may change the biome of the region. It can create a lake where none existed before, alter the flow of a river, or encourage other changes that impact weather patterns. People tend to use more irrigation when there’s a reservoir available, which would not be an action taken if a river was allowed to flow freely.

These changes can impact the quality of life for the people who live around the area of the dam, impacting their livelihood in uncountable ways.

5. Hydroelectricity isn’t scalable when there is a lack of water.
Seasonal changes can impact how flexible this renewable resource is for many communities. A hot summer without much rain can lead to less water flowing through a river. It can also cause reservoir levels to decrease because less precipitation impacts the surrounding area. That means there is less availability for power generation because the turbines can’t spin as efficiently.

This disadvantage primarily impacts the traditional forms of hydroelectricity, but it could also alter how the tides come in as time passes.

6. It can produce ecosystem damage, including the loss of wetlands.
The large reservoirs that form behind a dam with a hydroelectric power plant can submerse an extensive area upstream. This process of filling in to create a lack can destroy lowland valleys, river forests, marshes, and other forms of wetland. This disadvantage also changes the downstream grasslands from the site, creating damage to the local environment that changes wildlife habitats.

We have learned to counter this disadvantage by allowing water flows to occur frequently downstream. Fish ladders and other accommodations allow for marine life to adapt to the changing environment. Aquatic birds can learn to live around the new shoreline of the reservoir. Nature tends to adapt, but there are no guarantees to be found here.

7. Hydroelectricity facilities can force families to relocate.
An entire city was built to accommodate the workers that came to build Hoover Dam in the 1930s. When a reservoir fills in behind the facility, property owners that are within the new boundaries of the lake must move since their homes will be underwater. The World Commission on Dams estimates that up to 80 million people in total have been displaced because of this infrastructure need. The creation of Lake Mead flooded the community of St. Thomas, Nevada, turning it into a ghost town.

St. Thomas was settled by Mormon pioneers in 1865. It is said that the final resident of the town rowed away from his home in 1938.

8. Dams are a natural target for sabotage and terrorism.
Hoover Dam had only been completed for about a year when the American government learned that there was a German plot in place to destroy it. The Nazis wanted to place bombs at the intake towers so that the power supply to the aviation manufacturing facilities in southern California would get disrupted. At one point, the facility had its own police force, and the Army provided personnel to guard the structure.

These threats still exist today, although it doesn’t come from governments necessarily. Terrorist groups could sabotage these facilities to create power disruptions while causing downstream problems that could take many lives.

9. It can create resource conflicts on some bodies of water.
The number of hydroelectric facilities on the Colorado River is causing the flow to drop to dangerously low levels. When combined with issues like climate change and over-irrigation, the outlet for this body of water no longer reaches the sea. The means shellfish, waterfowl, and shrimp are in dramatically lower numbers in the Gulf of California. Damming rivers or installing other energy plants can change how people access resources, leading to cross-border conflicts over who has what right to use rivers, shores, and streams.

10. Hydroelectricity can only work in specific areas.
The vast majority of the hydroelectricity facilities that operate in the United States are located in the Pacific Northwest and California. The presence of flowing rivers and streams in these mountainous areas allows for significant energy production. Interior regions don’t get to experience these benefits as often because they don’t have the geographical infrastructure to support a significant installation.

You can’t install a tidal energy collector somewhere that doesn’t experience the tides. If you dam a small stream, that won’t have the same impact as placing a facility on the Mississippi River. This renewable resource faces the same natural availability limitations that wind, solar, and similar energy producers face.


The advantages and disadvantages of hydroelectric energy show us that society feels that the benefits of these structures outweigh the potential negatives that exist. These facilities give us the opportunity to reduce ongoing greenhouse gas emissions, but they also force people and wildlife to relocate because of the habitat destruction they cause. It is cleaner than combusting fossil fuels, although carbon dioxide and methane emissions still happen over time.

Before installing any new resources, we must study the impacts that any of the qualifying structures would have on local habitats.

The future of hydroelectricity may involve smaller turbines that communities can place on local waterways to create localized resources. This approach would reduce the threat that large-scale facilities provide without sacrificing the benefits of the power we can create with this technology.

About the Author
Brandon Miller has a B.A. from the University of Texas at Austin. He is a seasoned writer who has written over one hundred articles, which have been read by over 500,000 people. If you have any comments or concerns about this blog post, then please contact the Green Garage team here.