Wave energy: a promising renewable energy source

Wave energy is a renewable form of energy that uses wave power to generate electricity. With considerable energy potential, wave energy offers a sustainable, environmentally-friendly alternative to fossil fuels. This article explores how wave energy works, the advantages and disadvantages associated with it, and the technology’s potential applications.

Wave energy is about five to 10 times more expensive than solar and wind, according to Jeff Hansen from the University of Western Australia’s wave energy research center.https://www.abc.net.au/news/2018-09-22/power-company-carnegie-energy-hit-by-wave-of-discontent/10289772

How wave energy works

Wave energy comes from the oscillatory movement of waves, which is generated by wind blowing over the ocean surface. This energy is then converted into electricity using a variety of technologies, which can be classified into three main categories: float systems, oscillating water columns (OWCs) and underwater devices.

Float systems use buoys or floats to capture wave motion and convert it into electricity. Oscillating water columns, on the other hand, work by exploiting the air compression inside a closed chamber caused by wave movement. Finally, underwater devices use submerged turbines to harness the kinetic energy of waves.

Advantages of wave energy

One of the main advantages of wave energy is its renewable nature. Unlike fossil fuels, wave energy is inexhaustible and produces no greenhouse gases when converted to electricity. What’s more, waves are more predictable and consistent than other renewable energy sources, such as wind and solar, enabling more stable electricity production.

Wave technologies also have a low visual impact, as they can be installed off the coast, far from populated areas. In addition, subsea devices have a reduced environmental impact, as they are less likely to interfere with marine life and coastal ecosystems.

Disadvantages and challenges

Despite its advantages, wave energy also presents drawbacks and challenges. The initial cost of investment and installation of wave devices can be high, which may discourage some investors. In addition, servicing and maintenance can be costly due to the corrosive marine environment and harsh weather conditions.

The environmental impact of wave technology must also be taken into account, including effects on marine life and possible disruption of coastal ecosystems. Wave energy projects therefore require rigorous planning and assessment to minimize negative environmental impacts.

Wave technologies and systems

Key wave technologies include the Pelamis Wave Energy Converter, which uses articulated floats to convert wave energy into electricity, and the WaveRoller device, which harnesses the rocking motion of waves to drive a submerged turbine. Other technologies under development include flexible membrane devices and vortex energy recovery systems.

Possible applications

Wave energy can be used to generate electricity for national grids or to power local facilities, such as islands and isolated coastal communities. It can also be combined with other renewable energy sources, such as wind and solar, to create hybrid energy systems. In addition, wave energy can contribute to energy storage, by using excess electricity generated to pump water into reservoirs at altitude, which can then be released to generate electricity in times of high demand.

Companies

Companies in this niche include Carnegie Clean Energy and Hace Wave Energy (two projects that don’t seem to be very dynamic), Seabased and AW Energy (which seem to be making slow progress). The solutions appear to be relatively immature.

Examples of successful wave energy projects

Several wave energy projects have been successfully implemented around the world. Notable examples include Iceland’s wave power plant, which uses oscillating water column technology to generate electricity, and the Wave Hub project in the UK, which serves as a test bed for wave devices and promotes the development of this technology.

1. The Pelamis project, developed by Scottish company Pelamis Wave Power, uses articulated floats to convert wave energy into electricity. The Pelamis devices, resembling sea serpents, are anchored to the ocean floor and move with the waves, generating electricity via hydraulic cylinders. Although the company went bankrupt in 2014, the technology continues to be studied and could be used in future projects.
2. The Oyster project, developed by Scottish company Aquamarine Power, is a flexible membrane device that captures wave energy at the surface. As the waves push against the membrane, the water is compressed and sent to a hydroelectric power station on the coast, where it drives a turbine to generate electricity. The project has been tested off the coast of Scotland, but its development is currently on hold due to financial difficulties.
3. The Mutriku wave power plant, located in Spain’s Basque Country, uses oscillating water column technology to convert wave energy into electricity. Inaugurated in 2011, it has a capacity of 296 kW and is the first wave power plant in commercial operation in Europe.