Wave energy: what it is, how it works, types, examples, advantages and disadvantages

Wave energy is a form of renewable energy that is obtained from the movement of waves in the sea. This energy is harnessed through technologies that capture the kinetic and potential energy generated by the sway and height of the waves, converting it into electricity. Unlike other renewable energy sources, waves are constant and predictable, allowing for more stable power generation.

In this other article you can learn about the different Types of energy and examples.

The operation of wave energy is based on the conversion of wave movement into electricity through systems that transform the mechanical energy of water into electrical energy. There are several technologies to harness this energy. These are the most common:

• Flotation buoys: the movement of the buoys activates a system of pistons or generators located inside the buoy or on the seabed, which converts the energy of the movement into electricity.
• Oscillating water columns: when a wave arrives, it raises the water level inside the chamber and compresses the air inside, which passes through a turbine that converts the energy of the air flow into electricity. When the wave recedes, the air is sucked back in, maintaining the flow.
• Termination devices: This type of technology uses fixed structures that intercept waves to create pressure that moves a piston or plunger system, generating energy.
• Floating wave devices: These are systems of several connected sections that float on water. As they move with the waves, they generate energy through a system of hinges and pistons.

Wave energy can be classified according to different criteria, generally depending on the location of the system and the collection technology used:

• Onshore wave energy: Onshore systems are located on or near the coastline. Being more accessible, they are usually easier to install and maintain. However, they are more exposed to changes in the coastal environment, such as storms or erosion, and possible impacts on the nearby ecosystem. Oscillating water column (OWC) devices are often used in this location.
• Offshore wave energy: Offshore systems are placed offshore, where waves tend to be more constant and stronger. Being far from the coast, they can take better advantage of the movement of water without interfering with the coastal landscape, although installation and maintenance are more expensive. Open sea systems include flotation buoys and some edge devices, which can be anchored to the seabed or float on the surface.

There are projects around the world that exemplify different wave energy approaches and technologies. Let’s see some notable examples:

Pelamis Wave Power (Scotland)

The Pelamis system is made up of several connected segments that resemble a floating snake. As they move with the waves, the segments flex and compress hydraulic generators located at the joints, generating electricity.

Wave Hub (UK)

The Wave Hub is a project in Cornwall, UK, that acts as a subsea connection platform to test various wave energy technologies. This infrastructure allows multiple devices from different companies to connect at the same time to generate electricity and share it with the British electricity grid.

Mutriku Wave Power Plant (Spain)

The Mutriku wave energy plant, located in the Basque Country, is one of the first commercial wave energy facilities in Europe. It uses oscillating water column (OWC) technology, which takes advantage of air chambers located in the port’s breakwater. As the waves rise and fall, the air in the chambers is compressed and passed through turbines that generate electricity.

Let’s see what the main advantages and disadvantages of wave energy are:

Advantages of wave energy

• It is a renewable and clean energy source: It is a clean energy source that does not produce greenhouse gas emissions or pollutants during the generation of electricity.
• Take advantage of a constant and predictable resource: Waves are generally more constant and predictable than wind or sunlight, since they depend on global atmospheric phenomena that act on the oceans on a regular basis.
• High energy density: Waves contain a greater amount of energy per area than other renewable sources, such as wind.
• Reduces dependence on fossil fuels: By offering a renewable alternative, wave energy helps reduce the use of fossil fuels and contribute to the transition towards a more sustainable energy system.
• Minimal visual impact for submerged devices: Unlike wind turbines or large solar panels, submerged wave energy devices, such as buoys and panels on the seabed, are less visible and therefore have less visual impact on the coastal landscape.

Disadvantages of wave energy

High installation and maintenance costs: Wave energy devices must withstand extreme marine conditions, such as corrosion, storms and the force of waves. This requires durable materials and designs, which significantly increases installation costs. Furthermore, maintenance in the marine environment is often complex and expensive.

• Environmental and marine life impact: Although less invasive than other forms of energy, wave energy can affect marine ecosystems.
• Interference with maritime activities: The presence of wave-powered devices can interfere with traditional activities at sea, such as fishing, shipping and tourism.
• Limited to certain geographic areas: Wave energy is only viable in areas with sufficient wave activity, such as coasts exposed to open oceans and seas with strong waves.
• Developing technology: This type of energy is still in a development stage and has not been implemented on a large scale in many parts of the world.

• Both renewable energies take advantage of the movement of water, but they do it differently and depend on different phenomena. While wave power is based on the movement of waves on the sea surface, tidal power takes advantage of the movement of the tides.
• The availability of wave energy is relatively constant over time, but waves can vary in size and intensity depending on the climate and seasons. On the other hand, tidal energy, depending on the tides, is highly predictable.
• They also differ in energy harvesting technology. Wave power uses devices such as those we have seen of floating buoys, oscillating water columns and segmented platforms, which convert the sway of the waves into mechanical or hydraulic energy, which is then transformed into electricity. Tidal energy harnesses the energy of the tides with tidal dams and current turbines.

Now that you have learned about what wave energy is, we encourage you to learn more about Tidal Energy: advantages and disadvantages.

If you want to read more articles similar to Wave energy: what it is, how it works, types, examples, advantages and disadvantages, we recommend that you enter our Renewable energies category.