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Hydropower: Everything You Need to Know About

Water is an incredibly powerful resource. Not only is it necessary for life, but it can also be used to generate energy. Hydropower is one of the oldest forms of renewable energy and it’s still being used today to generate electricity.

It uses the kinetic energy from flowing water to generate electricity. The use of moving water to generate electricity goes back over two thousand years. Chinese waterwheels were used to power grain mills and irrigation pumps.

They also used water power in manufacturing paper. In the early days of papermaking, trip hammers powered by vertical water wheels were used to pound and hull grain.

In the early 1800s, hydropower was used to power factories in the United States. Today, hydropower accounts for 10% of total energy, and 96% of renewable energy production in the US.

One of the main reasons hydroelectricity is so popular is because of the high efficiency rates. Hydropower plants can have efficiency rates of up to 90%.

Hydroelectric plants have a long lifespan when compared to most other forms of energy production. Because it runs on falling water, it doesn’t require fuel, which means there are very few emissions.

Hydroelectric generators are extremely responsive to changing system conditions. This is due to the fact that water is stored in reservoirs and can be released when needed.

This flexibility makes hydroelectricity ideal for use with intermittent renewable energy sources, such as solar and wind power. Hydroelectricity can supplement these energy sources when the sun isn’t shining or the wind isn’t blowing.

As a result of these advantages, hydroelectric projects continue to be attractive sources of electric power.

In this post, we will discuss everything you need to know about hydropower. We will talk about how it works, different types of hydropower plants, the advantages and disadvantages of hydropower, and some interesting facts about this renewable energy source.

Let’s get started!

What is hydropower?

Hydropower is a renewable energy source that uses the force of moving water to generate electricity.

Hydropower Plants on Drina River

It uses the kinetic energy from flowing water to generate electricity. It is considered a renewable energy source because water is constantly recycled through the hydrologic (water) cycle.

What makes hydropower a renewable energy source is the water cycle. The sun evaporates water from oceans, lakes, and rivers. This water vapor condenses and falls back to the earth as precipitation.

The water then flows back into oceans, lakes, and rivers through a process called runoff. The water is then drawn back up into the atmosphere and the cycle starts over again.

During this process, a small amount of the water’s energy is converted into electricity. So, what creates the hydropower is primarily the elevation difference between where the water starts (higher elevation) and where it eventually returns (lower elevation).

How does hydropower work?

Hydroelectric power is generated by moving water. The hydrologic cycle which provides the earth with water is powered by the sun. The sun’s heat energy evaporates water from the earth’s surface which eventually condenses and falls back to the surface as precipitation.

We have also mentioned that the elevation difference between where the water starts (higher elevation) and where it eventually returns (lower elevation) is what creates hydropower.

The difference in elevation is called the head and is measured in feet or meters. The head is the primary determinant of the amount of energy that can be extracted from flowing water.

However, capturing the energy of moving water requires a dam. Dams are built across rivers to store water in reservoirs. When the dam releases water from the reservoir, the water flows through turbines.

The turbines spin and generate electricity. The dam controls the release of water so that it can be used to generate electricity when demand is high.

The flow or volume of water is very important in generating hydroelectric power. The more water flowing through the turbines, the more electricity that can be generated.

We aren’t going to make calculations for the amount of electricity that can be generated by a hydroelectric dam in this post. But here’s what is essential to know about the topic.

The flow of water is measured in cubic feet per second (CFS) or cubic meters per second (CMS). The volume of water is determined by the size of the watershed, or the area of land that drains into a river or stream.

The speed at which water flows is determined by the slope of the land. Steep slopes result in fast-moving water, while gentle slopes produce slower-moving water.

The head and flow of water combine to create hydroelectric power. The higher the head and the greater the flow, the more power that can be generated.

Hydropower is generated in facilities referred to as hydroelectric power plants. In order for hydropower to be generated, water must first be collected or stored in a reservoir.

The water is then released from the reservoir and flows through a turbine. The force of the moving water turns the blades of the turbine which, in turn, rotates a generator to produce electricity.

Dams are required to ensure a steady supply of water to the turbine. The dam also controls the release of water so that it can be used to generate electricity during periods of high demand. Dams can also be used to store water for use during dry periods.

Dams are often located in remote locations, which can make it difficult to transport the electricity they generate to population centers. In order to overcome this challenge, transmission lines and other facilities are used to connect the hydroelectric power plant to the electricity grid.

Every power plant has transformers that raise the voltage of the electricity so that it can be transmitted over long distances via high-voltage transmission lines.

The electricity is then sent to substations where the voltage is lowered so that it can be distributed to consumers via the low-voltage power lines that make up the electricity grid.

The power grid is responsible for more than just transporting electricity from the hydropower plant to the substation. The grid is a complex system that allows electricity to flow from multiple power plants in order to meet varying levels of demand.

So, the energy used to charge your phone could be generated by a hydroelectric plant, a wind turbine, a nuclear plant, or a combination of energy sources that we haven’t even named yet.

What are the components of a hydroelectric power plant?

There are many different types of hydroelectric power plants. But they all have three basic components: a dam, a turbine, and a generator.

Other than these three essential components, the specific design of a hydroelectric power plant can vary greatly. As you may have guessed, there will be many more components in a hydroelectric power plant including:

  • Pipes
  • Penstocks
  • Intake Gates
  • Spillways
  • Tailraces
  • Desanding Basins
  • Forebays
  • Afterbays
  • Surge Tanks
  • Valves
  • Electrical Switchgear
  • Substations
  • Automation & Control Systems

We are going to take a more in-depth look at each of these components in future posts. But for now, let’s just get a basic understanding of what each of these components does.


A hydroelectric dam is one of the most important parts of a hydroelectric power plant. A dam is a massive man-made structure designed to hold back a body of water.

Dams are built for a variety of reasons, including the generation of hydroelectric power. They are also built to manage river flow and regulate flooding. Small-sized dams known as weirs are erected in some rivers to control and measure water flow.

Dams are a sort of retaining structure that is used to create enormous quantities of water known as reservoirs. These reservoirs can be utilized for agriculture, generation of electricity, or water delivery.

These constructions are placed on riverbeds to hold back water and raise the water level. Dikes can be constructed alongside the dam to boost the dam’s efficacy by preventing water from exiting the reservoir via secondary paths.

Dams can range in size from small to massive. The tallest dam in the United States is near Oroville, California, and it rises 230 meters tall and is 1.6 kilometers across. The

Jinping dam on the Yalong River in China is the tallest dam in the world, standing at 305 meters. There are about ten thousand dams in Canada, with 933 of them classified as major dams.

The Mica dam on the Columbia River, which stands 243 meters tall, is Canada’s tallest dam. The W.A.C Bennett dam on the Peace River is another famous Canadian dam, with a reservoir volume of 7.4 x 109 cubic meters and a height of 190.5 meters.

These dams are difficult and labor-intensive to build. Water is redirected or stopped from flowing through the construction site before it begins. Following water diversion, the foundation area is cleaned and dug, and the rock or sediments that will serve as the foundation are mended and deemed solid.

This is done to ensure that the rock or sediments do not shift or fail as a result of the dam’s and reservoir’s load. To strengthen the foundation, rock bolts may be utilized as support.

Rock bolts and nets may be placed above the dam to keep rocks from falling on the dam. After that, forms are created around the dam’s edges, rebar is inserted inside, and concrete is pumped in.

This is done in stages, and the concrete is poured in a block configuration bit by bit. Once the dam is complete, the reservoir is allowed to fill in a regulated manner. During this time, the dam is being monitored. Other constructions are then constructed to make the dam operational.

Dams are only one component of a comprehensive hydroelectric complex, but they are the most conspicuous and noticeable component of the system. A hydroelectric dam’s goal is to offer a location for converting the potential and kinetic energy of water to electrical energy via a turbine and generator.

Dams are structures that hold back and release water in a regulated manner via hydraulic turbines, allowing the mechanical energy of the water to be converted to electrical energy.

Typical dams function to create a reservoir in which water is stored at a specific height. The amount of energy that may be generated is determined by the height and the velocity at which the water flows from the reservoir through the turbines.

The hydroelectric power equation can be used to calculate this. As the dam’s height climbs, so does the amount of energy generated. A gate at the top of the dam is used to either stop or allow the release of water from the reservoir. To suit electrical requirements, this gate can be opened or closed.

Between the dam’s top and the turbines, a series of channels known as penstocks guide the water down and manage the slope of the falling water to ensure the dam’s maximum effectiveness.

Finally, turbines can be housed within the dam construction itself, which is where the energy conversion occurs. After passing through the turbines, the water is released back into the river via a tailrace at the dam’s base.


A turbine is a device that converts the moving energy of water into mechanical energy. The rotating blades of the turbine are turned by water pressure or moving water, which in turn rotates a shaft connected to a generator.

Generators work by using magnets to create electricity. When the turbine’s blades rotate, they cause a shaft connected to the generator to spin.

Faraday’s Law of Induction states that a moving conductor in a magnetic field produces electricity. This is how generators produce electricity. The movement of the turbine’s blades creates a magnetic field, which in turn causes the generator to produce electricity.

There are two main types of turbines: reaction and impulse.

Reaction turbines

A reaction turbine generates electricity by combining the forces of pressure and moving water. A runner is positioned directly in the water stream, allowing water to pass over the blades rather than striking each one separately.

Reaction turbines are the most frequent type now employed in the United States and are typically used for sites with lower heads and larger flows. The two most popular types of reaction turbines are Propeller (including Kaplan) and Francis. Kinetic turbines are another type of reaction turbine.

Propeller Turbine

A propeller turbine typically has a runner with three to six blades. Water is continually in touch with all of the blades. Consider a boat propeller in motion in a pipe.

The pressure in the pipe is constant; otherwise, the runner would be out of balance. The pitch of the blades might be fixed or changeable. Aside from the runner, the essential components include a scroll case, wicket gates, and a draft tube. There are various types of propeller turbines:

Bulb Turbine

The bulb turbine is a variant of the propeller-type turbine (similar to the Kaplan turbine). The generator is enclosed and sealed within a streamlined watertight steel casing situated in the center of the water route in the bulb turbine design.

The generator is powered by a variable-pitch propeller situated at the bulb’s downstream end. Unlike the Kaplan turbine, water enters and departs this unit with little change in direction.

The small nature of this design provides for greater flexibility in powerhouse design. Bulb turbines, on the other hand, can be a little more difficult to service because they require particular air circulation and cooling within the bulb.

Straflo Turbine

The Straflo turbine is a reaction turbine that uses an axial-flow runner. The water enters the runner from the side and exits in the same direction along its axis, perpendicular to the main shaft. This design was first used in Francis turbines but has been adapted for use with propeller and Kaplan runners as well.

Tube Turbine

Tube turbines are a type of reaction turbine that uses a series of curved tubes (instead of a scroll case) to guide water to the blades of the runner. The water enters the tube at one end and exits at the other, similar to a Francis turbine.

The main difference between this design and others is that the tubes are much shorter, which means they can be used on lower heads.

Kaplan Turbine

The Kaplan turbine is a reaction turbine that uses an adjustable propeller. The blades can be rotated to adjust the pitch, which allows the runner to be used on a wide range of heads.

This type of turbine is named after Viktor Kaplan, who invented it in 1913. It is one of the most popular types of turbines used today.

Francis Turbine

Francis turbines are reaction turbines that use a fixed-blade runner. The blades are positioned in a spiral around the main shaft. Water enters the runner from the side and exits along its axis, perpendicular to the main shaft.

This type of turbine was invented by James Francis in 1848 and is one of the most common types of turbines used today.

Kinetic turbine

Kinetic energy turbines, also known as free-flow turbines, create electricity by using the kinetic energy of flowing water instead of the potential energy from the head.

The systems are capable of operating in rivers, man-made channels, tidal streams, and ocean currents.

Because kinetic systems use the natural flow of a water stream, they do not require water to be diverted through man-made channels, riverbeds, or pipelines, but they may have applications in such conduits.

Because existing structures such as bridges, tailraces, and channels can be used, kinetic systems do not necessitate massive civil works.

Impulse Turbine

Impulse turbines are reaction turbines in which the water hits blades on the runner, causing it to spin. The water then flows out of the runner in a jet. The force from the jet hitting the blades is what causes the impulse turbine to rotate. This type of turbine is typically used on high heads (70m or more).

There are two types of impulse turbines: Pelton turbine and Cross-flow turbine.

Pelton Turbine

Lester Allan Pelton designed the Pelton turbine in the 1870s. A Pelton wheel includes one or more free jets that discharge water into an aerated zone and impinge on the buckets of a runner.

Pelton turbines are typically employed in applications with very high heads and low flows. An impulse turbine does not require draft tubes since the runner must be situated above the maximum tailwater to allow operation at atmospheric pressure.

Cross-flow Turbine

The first practical cross-flow turbine was created by an Austrian engineer named Anthony Michell in the early 1900s.

Hungarian engineer Donát Bánki went on to improve it, and German engineer Fritz Ossberger went on to improve it even further. In a cross-flow turbine, a nozzle with an elongated, rectangular section is directed against curved vanes on a cylindrically-shaped runner.

When using a cross-flow turbine, water passes through the blades twice, increasing the efficiency. To begin with, water flows inward; then, it flows outward. At the turbine’s inlet, a guide vane directs the flow into a specific area. Unlike the Pelton, the cross-flow turbine can handle higher water flows and lower heads.

The cross-flow turbine uses an involute or spiral casing to direct water onto the blades of the runner. The water flows into the runner at one end and exits at the other, perpendicular to the main shaft. This type of turbine is typically used on low heads (less than 30m).


When the dam gates open, water flows down the penstock to the turbine, usually through a shut-off valve.

Penstocks dam hydroelectric plant

Penstocks are pipes that carry water from the intake to the powerhouse, where it is used to generate electricity.

A water hammer is a phenomenon in which the pressure on the inside surface of penstock increases or decreases rapidly due to a sudden increase or decrease in the load.


For power plants far from dams and reservoirs, water is transported via open channels, tunnels, or pressure shafts lined with concrete or steel. This will prevent vortices from forming above the intake entrance, which could cause problems with turbine operation.

Surge Tank

It is common for a surge tank to be installed in a power plant’s water intake system to absorb any water surges caused by sudden loading or unloading of the generator through the opening or closing of the inlet valve or wicket gate.

It is possible to control the amount of water that enters the turbine through the turbine’s wicket gates.

Wicket Gates

Wicket gates are located at the inlet to the turbine. These gates control the amount of water that flows through the turbine and, as a result, the amount of power that is generated.

The size and shape of wicket gates can vary depending on the type of turbine being used.


Spillways are used to release water from a dam when the water level gets too high. The water flows down the spillway and into a body of water below the dam.

Spillways can be either natural or man-made. Natural spillways are usually made of rock or soil and are located where there is a depression in the ground. Man-made spillways are usually made of concrete or steel and are located next to the dam.

Diversion Gates

Diversion gates are used to divert water around a dam when the water level gets too high. They are usually made of concrete or steel and are located next to the dam.

Diversion gates are used to protect the dam from water surges caused by heavy rains or floods. When the water level gets too high, the diversion gates are opened and the water is diverted around the dam.


Valves are used to control the flow of water in a power plant. There are two types of valves: intake valves and outlet valves. Intake valves are located at the inlet to the turbine and control the amount of water that flows into the turbine.

Ancient rusty machinery, hydropower station

Outlet valves are located at the outlet from the turbine and control the amount of water that flows out of the turbine.


Large water pumps

Pumps are used to pump water from the reservoir to the powerhouse. Pumps are usually located in the powerhouse and are powered by electricity. The pumps are operated by a control panel in the powerhouse.

Electrical Equipment

The electrical equipment in a power plant includes generators, transformers, switchgear, and cables. The generators are used to convert the mechanical energy of the turbine into electrical energy.

Transformer High Voltage Electrical

The transformers are used to increase or decrease the voltage of the electrical energy. The switchgear is used to control the flow of electricity. The cables are used to connect the electrical equipment.

Operating a power plant requires a lot of equipment and skilled workers. Because of this, power plants are usually owned and operated by utility companies.

Classification of Hydropower Plants by Facility Type

There are three main types of hydropower plants, each with a specific operation or flow.

They are Run-of-river (RoR), storage, and pumped storage. Besides that, there is a fourth category known as in-stream technology, which isn’t mature enough to be used commercially.

Run-of-River (RoR)

A run-of-river plant harnesses the kinetic energy of moving water to spin a turbine, without using a dam or reservoir. It derives the majority of its energy for power generation from the available flow of the river.

A hydroelectric plant of this type may contain some short-term storage (hourly, daily), allowing for some adjustments to the demand profile, but the generating profile will be governed by local river flow patterns to variable degrees.

Since precipitation and runoff affect generation, there could be significant daily, monthly, or seasonal fluctuations. For RoR HPPs, the generation profiles will be even more variable when they are located in small rivers or streams with a wide range of flow rates.

RoR HPPs may use a channel or pipeline (penstock) to transfer water from the riverbed to a hydraulic turbine, which is linked to an electricity generator.

Cascades of RoR projects can be built along a river valley, often with a reservoir-type HPP in the upper reaches of the valley, allowing both to benefit from the combined capacity of the various power stations.

RoR HPPs can be installed for a low cost and have a lower environmental impact than storage hydropower plants of comparable size.

Run-of-river hydropower plants rely on the natural flow of river water and do not require significant storage. As a result, they are less flexible than (pumped-)storage hydropower plants; in reality, run-of-river power plants must precisely adjust the water level at the intake in line with the incoming river flow.

The electrical output of run-of-river power plants is determined by the availability of water in the river and, as a result, varies significantly throughout the year. Because the hydrological forecast is good enough for the timescales required in the electricity market, run-of-river hydropower projects often generate baseload power.

This dynamic cycle allows for some short-term storage and thus demands adaptation, particularly for ancillary services like frequency and voltage control. Design considerations for run-of-river power plants can be optimized for both large flow rates and low head in mountain regions.

On some occasions, river water may be channeled via a canal, tunnel, or penstock to transport it to a hydraulic turbine, which is tied to an electrical generator. Run-of-river plants can also be incorporated in a cascade or multistage scheme, in which two or more plants are positioned in sequence on the same river.

Cascading schemes can provide peak energy in a few hours by increasing production in all power plants at the same time.

A storage power plant is frequently positioned in the upper catchment because it enables water flow regulation to ensure continuous energy output from downstream run-of-river plants and to provide a few hours of peak energy in the entire cascade.

Because regulated rivers flow more uniformly throughout the year, the combined cascade of dams and reservoirs allows for more efficient electricity generation and can also be used to absorb extra energy while reducing river flow.

Storage Hydropower 

Storage hydropower is a type of hydropower that stores water in reservoirs for later use. This reduces reliance on unpredictable inflows.

The generating stations are linked to the reservoir via tunnels or pipelines at the dam’s toe or further downstream. The landscape dictates the type and design of reservoirs, and many of the world’s artificial lakes are built in the inundated river valleys.

In mountain plateau areas, high-altitude lakes form another type of reservoir that often retains many of the original lake’s qualities. In these cases, the generating station is frequently linked to the lake that serves as a reservoir by tunnels that rise beneath the lake (lake tapping).

In Scandinavia, for example, natural high-altitude lakes serve as the foundation for high-pressure systems with heads that can reach over 1,000 m.

One power plant may have tunnels leading from multiple reservoirs and, when possible, may be linked to neighboring watersheds or rivers. The design of the HPP and the type of reservoir that can be developed are heavily influenced by geography.

Storage power plants work by impounding water behind a dam. To generate power, water is released from the reservoir and directed to the turbine.

The generating stations can be positioned directly at the dam toe without water diversion, or further downstream with water diversion from the river; in this case, the stations are connected to the reservoir by channels, tunnels, or penstocks.

Storage plants offer the advantage of being less reliant on the natural flow of water; in fact, depending on their storage capacity, they can operate independently of the hydrological inflow by storing water during the rainy season and using it during the dry season and even inter-annually.

In other words, they can easily store potential energy and convert it to electrical energy as needed in a flexible manner.

As a result, these plants are frequently employed for heavy load following and meeting peak demand, allowing for the optimization of base-load power generation from less flexible electricity sources. The greater the reservoir of a hydropower plant, the more storage it can offer.

High-altitude lakes can be utilized as reservoirs in mountain areas while retaining the original lakes’ characteristics. In this example, the power plant is connected to the lake via pressure tunnels and shafts pierced through the lake’s surface.

The hydraulic head has a maximum reach of 2000 meters. In other places, artificial lakes are typically formed by flooding (river) valleys. A power station can be linked to neighboring river basins by tunnels that connect to multiple reservoirs.

Hydropower plants with big reservoirs provide the highest degree of service. Such facilities may store energy on a massive scale during periods of low demand and make it available during periods of peak need on an hourly, weekly, monthly, or even yearly basis.

Furthermore, their quick response time enables them to handle rapid swings in demand. Hydropower facilities with a small reservoir are primarily intended to adjust generation on a daily or maximum weekly basis.

Pumped storage (PSH)

Pumped storage (PSH) is a type of storage hydropower where water is pumped from a lower elevation reservoir to an upper elevation reservoir when electricity is plentiful and inexpensive, often at night.

Then the water can be released back to the lower elevation reservoir through turbines during periods of high electric demand, such as daytime or peak periods.

Pumped storage hydropower is the largest-capacity form of grid energy storage available.

Pumped-storage hydropower facilities have two reservoirs, one lower and one upper. Tunnels or penstocks connect the two reservoirs.

A pumped storage plant transports water between the two reservoirs. In production mode, the facility operates similarly to a traditional hydroelectric plant: water is discharged from the upper reservoir through the turbines to generate electricity.

In pumping mode, electrical energy from the grid is used to pump water from the lower reservoir to the upper reservoir (usually during off-peak periods using surplus electricity generated by base-load power plants).

In this situation, a motor generator is used to operate as a generator in the production mode or as a motor in the pumping mode.

In terms of the hydraulic system, there are two options: reversible pump turbines that can work in both directions (often of the Francis type) or separate pump and turbine, as in ternary systems. For heads of less than 600 to 700 m, reversible pump turbines are more prevalent.

When switching from the pumping mode to the production mode in this design, the rotational direction must be reversed, and vice versa. A ternary system provides greater flexibility because the pump and turbine are separated on the same shaft and no direction change is required.

Pumped storage power plants are intended to provide peak electricity during periods of high demand by operating on a daily and weekly cycle (the duration time for operation at full capacity is calculated by the storage capacity of the upper reservoir).

Energy storage facilities that use pumped-storage hydropower have the highest overall efficiency (cycle efficiency) and can store large amounts of energy.

Existing reservoirs or lakes may be used depending on the geography and hydrological characteristics of the site. If no reservoirs are available, new ones must be built.

The lower reservoir is sometimes a river controlled by a weir or a run-of-river power plant. Other ideas call for the utilization of subsurface reservoirs. The utilization of abandoned mines, caves, and man-made storage reservoirs has been studied.

Another possibility is to use the sea as the lower or upper reservoir, however, there is currently only one example of seawater pumped storage.

Finally, small-scale pumped-storage hydropower plants can be developed within infrastructures including drinking water networks, navigation locks, and artificial snowmaking infrastructures.

These plants are typically fairly tiny in size and provide distributed energy storage as well as distributed flexible electricity output.

Pumped-storage hydropower facilities are net energy consumers, with a ratio of produced energy to consumed energy for pumping ranging between 70% and 85%.

This disadvantage is offset by the flexibility given by these plants. Indeed, pumped hydropower is the more mature, adaptable, and cost-effective form of bulk energy storage at the moment.

As a result, pumped storage hydropower facilities play two roles: balancing the grid for demand-driven oscillations and balancing the grid for generation-driven fluctuations.

Pumped storage power facilities, like traditional reservoir-type hydropower plants, may provide a full range of grid-stabilizing services.

In-stream hydropower technology

In-stream hydropower, also known as in-channel hydropower, is a type of small hydropower plant. It uses the flow of water in a river or stream to generate electricity without the need for a dam or reservoir.

It is crucial to note that hydropower generation does not always necessitate extensive civil works.

In-stream technology is the use of hydrokinetic turbines to capture the energy of naturally flowing water, such as streams, tidal flows, or open ocean flows, without impounding the water.

This technology can be implemented into existing infrastructure such as weirs, barrages, canals, or falls to generate electricity. These facilities operate similarly to a run-of-river setup.

Offshore hydropower, a less known but rising category of technologies that employ tidal currents or the strength of waves to generate energy from seawater, has enormous development potential.

Hybrid hydropower 

In addition to the four types of hydropower plants listed above, the concept of hybrid power plants is worth considering.

Hybrid power plants operate as integrated units with one or more forms of generating and can be located on a single site or as part of a microgrid.

Hybrid power plants can be connected to the grid or located far from the grid in remote locations, where they are the primary source of power. Hydropower can be integrated with solar or wind power in hybrid power plants to boost the stability and reliability of the electricity supply.

The hybridization allows PV panels or wind turbines to create energy when the sun or wind is accessible while conserving water for hydroelectricity to supplement during intermittent times when the sun or wind is not available.

When pumped storage is feasible, extra energy can be stored to meet peak demand. Another benefit of hybridization is the ability to use the same electrical infrastructure for both generators, saving overall capital expenditure.

Combining hydropower with floating photovoltaics may potentially provide additional benefits, as the installation of solar panels on dead water zones maximizes resource usage. However, care should be paid to the environmental impact of the floating structure and its anchoring.

Furthermore, by covering a large surface area of water, these systems help reduce evaporation and algae bloom.

The examples above are just a few of the various hybridization setups that are available, and further choices are still being explored. These are always adapted to the individual needs of the site for electricity and/or water services.

Environmental Impacts

Hydropower does not pollute the environment, but it does have negative effects. Water quality and fish passage have been addressed by both federal and non-federal hydropower facilities licensed by the Federal Energy Regulatory Commission in recent years.

Efforts to preserve dam safety, as well as the use of newly available computer technologies to optimize operations, have increased the number of opportunities to improve the environment.

There are still many unknowns regarding how to sustain hydropower’s economic viability while still safeguarding fish and other environmental resources.

Today, the majority of hydropower research and development is focused on the following areas:

  • Turbine-Related Projects
  • Fish Passage, Behavior, and Response
  • Hydrology
  • Water Quality
  • Monitoring Tool Development
  • Dam Safety
  • Operations & Maintenance
  • Water Resources Management

What are the benefits of hydropower?

There are many benefits to using hydropower, including:


Hydropower is a renewable resource, meaning it can be used over and over again without being depleted.

Low operating costs

Once a hydropower plant is built, the only cost of operating it is the electricity needed to power the pumps that send water back to the reservoir.

Low emissions

Hydropower plants do not produce emissions, making them a much cleaner option than other power sources such as coal-fired power plants.

Can be used for irrigation

In addition to generating electricity, hydropower can also be used for irrigation.

Can help with flood control

Hydropower plants can help with flood control by storing water in the reservoir during times of heavy rainfall.

Can be used as a backup power source

Hydropower can be used as a backup power source for other renewable energy sources such as wind and solar.

What are the drawbacks of hydropower?

There are also some drawbacks to hydropower, including:

Can impact the environment

Hydropower dams can impact the environment both upstream and downstream of the dam.

Upstream impacts include changes to the natural flow of the river and the loss of habitat for plants and animals.

Downstream impacts can include changes to the water temperature and quality, which can impact the plants and animals that live in the river.

Can impact recreation

Hydropower dams can also impact recreation, such as fishing and boating.

Can be expensive to build

Hydropower plants can be expensive to build, especially if the dam is large.

Can cause disruptions during construction

The construction of hydropower dams can cause disruptions to the local community, such as the loss of homes and businesses.


Hydropower is a clean and renewable energy source that has many benefits. However, it is important to consider the potential impacts on the environment and the local community before building a hydropower plant.

The future of hydropower is promising as research and development continue to find ways to make this renewable energy source more efficient, less impactful on the environment, and more available to a wider range of users.

Improved technology and a better understanding of environmental concerns will help unlock the potential for hydropower to provide clean, renewable energy for generations to come.