3 Different Types of Hydroelectric Power

3 Different Types of Hydroelectric Power

Hydroelectric power is one of the cleanest and most sustainable forms of energy generation. It doesn’t produce greenhouse gases, it is renewable (we won’t be running out of water anytime soon), and it’s available in most parts of the world. In this article, we’ll explore three different types of hydroelectric power plants.

3 Different Types of Hydroelectric Power

What are the different types of hydroelectric power

There are three types of hydroelectric power: run-of river hydropower, hydroelectric dams and tidal power.
Run-of-river hydropower is the simples of them all, and consists of a turbine installed in a stream of flowing water. The kinetic energy of moving water turns the turbine, which is connected to a generator.

Hydroelectric dams are the most common hydropower-generating powerplants. Dams rely on the gravitational potential energy of water, stored in a reservoir built of concrete, steel, rocks or earth.

Tidal power is the least common method of generating hydroelectricity. Tidal powerplants are typically located offshores, and use the kinetic energy of waves to generate electricity.

Each one of these three types of hydroelectric power comes with its own advantages and disadvantages. Let’s take a closer look at each one:

Run-of-river hydropower

types of hydroelectric power
A large scale run-of-river hydropower plant

Run-of-river hydropower is the simplest of all types of hydroelectric power and is usually found in rural areas. It works by using the natural flow of a river to turn turbines and generate electricity. This type of power is low-cost, fast to build, and can be used to provide baseload electricity generation.

Run-of-river hydropower is also the oldest form of hydropower. Dating back several thousands of years, our ancestors built large turbines at rivers to grind wheat. That’s right, historic wheat mills harnessed the power of moving water to crush grain.

Run-of-river hydropower is still quite common today. There are powerplants of varying sizes: ones that are built on small streams and produce just enough electricity to power a single house, or large scale powerplants that are built across major rivers, generating several thousand megawatts of electricity.

Advantages of Run-of-river hydropower:

1. They are relatively easy and cheap to build.

2. They provide a steady stream of electricity with no additional requirements.

3. They can be used to power private properties that do not have proper access to the grid.

Disadvantages of Run-of-river-hydropower:

1. They produce too little power in most occasions.

2. They tend to get damaged easily, and are often accompanied by costly maintenance.

Hydroelectric dams

types of hydroelectric power
Hoover Dam, Colorado river

hydroelectric dams are the most common types of hydroelectric powerplants, and the electricity they produce is the most common of the types of hydroelectric power circulated in the grid. They use the energy of falling water to turn turbines and produce electricity. The three main types of hydroelectric dams are: concrete, arch, and weir (small dams).

Regardless of the type of hydroelectric dam in discussion, they all work the same way: using the water stored in the reservoir to generate power.

Water stored in the reservoir contain a large amount of gravitational potential energy, since the reservoir is build on high ground. Water is released downstream through a floodgate, in controlled amounts. When water flows downwards, the gravitational potential energy gets converted to kinetic energy.

The kinetic energy of flowing water is used to turn turbines, which are connected a generator. The generator converts the kinetic energy to electrical energy, which is then transmitted through the grid.

Advantages of hydroelectric dams:

1. Dams are efficient, since they convert a large portion of the energy to electricity.

2, Dams produce electricity at a much lower cost than most other methods of generating power.

3. Dams produce a large amount of electricity. Often, a single dam is enough to power an entire town.

4. Dams are a reliable, controllable source of power. The flood gates can be adjusted based on demands.

Disadvantages of hydroelectric dams:

1. They are expensive to build, costing billions at times.

2. They can be unsafe, since a breach in the dam wall would result in a tsunami.

3. They can only be built in very specific locations, where the water supply is ample.

Tidal power

types of hydroelectric power
An underwater turbine

Unlike other types of hydroelectric power on this list, there are several completely different ways tidal power can be generated. What they all have in common is that the harness the kinetic energy in ocean waves to generate electricity. Two common types of tidal powerplants are wave buoys and tidal turbines.

Tidal turbines are in many ways similar to wind turbines. The only major difference is that while wind turbines use the kinetic energy present in air (wind), tidal turbines use kinetic energy present in water (waves) to generate power. In tidal turbines, an underwater turbine spins as a wave passes by, “pushing” on its blades.

Wave buoys, on the other hand, bop up and down as a wave passes by. This movement is transferred to a hydraulic pump, which pushes water at a high speed through a system. The pumped water will flow past a turbine, turning it and generating power as it exits the other end of the system.

Advantages of tidal power:

1. It will potentially never run out, since we will always have waves.

2. It is a reliable source of power. Ocean tides will be present throughout the seasons.

Disadvantages of tidal power:

1. It is expensive to build, since several wave buoys or underwater turbines will have to be built.

2. The equipment used in tidal powerplants require frequent repairs, which brings up maintenance costs.


Hydropower is without doubt one of the most prominent sources of renewable energy out there today. Many countries have invested heavily into building hydropower plants and with good reason.

There are three main types of hydroelectric power: Run-of-river, Hydroelectric dams and Tidal power.

Each one out of these three types of hydroelectric power comes with their own advantages and disadvantages. If you are interested in learning more about hydropower, be sure to visit our hydropower category page! You will find a blog written on every topic you’re interested in.

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