Introduction
In this report, I will be discussing the foundations for the usage of wave power. I will then proceed to investigate the research currently being undertaken to address the problems that are hindering the advancement of wave power to generate energy on a mass scale. Additionally, I will analyse this research from an environmental and economical perspective to make an on-balance evaluation of the benefits and limitations offered through these perspectives.
Wave power captures the energy provided by wind waves, to do tasks such as the generation of electricity, water desalination and pumping water. Wind waves are those that are generated when wind blows over the free surface of bodies of water, such as oceans, seas or ponds. As long as waves develop slower than the wind speed just above them, there is an energy transfer causing water to swell and crash as waves. Modern technology has allowed for the invention of various wave power devices that are able to obtain energy from waves. For example, in a wave power station, incoming waves cause water levels in a chamber to rise and fall. As a result, air rushes in and out of an opening at the top of the chamber. A turbine spun by this airflow is placed in the opening, whose rotation force (torque) powers a generator. The energy provided by wind waves is determined by the wave height, wave speed, wavelength, and water density.
Devices used to capture wave energy, such as a wave power station, however have a potential to have adverse effects on the surrounding marine environments. Although the impact varies across various designs, noise pollution could have serious implications if not monitored properly. Additionally, biophysical complications include shifts in sediment regimes, wellbeing of flora and fauna as well as water flow. Even when these factors are disregarded, there are still socio-economic factors to consider. Wave power stations and farms could result in the displacement of fishing or marine vegetable harvest grounds and the transit routes of commercial and recreation fisherman. Additionally, it could alter patterns of coastal erosion and beach nourishment. Another major issue is that although waves have the potential to generate about 2,700 gigawatts of power, only about 500 gigawatts can be obtained with the current technology available.
The Use of Science
In an attempt to advance the use of wave power to obtain energy to generate electricity, desalinate and pump water amongst other things, research is currently being undertaken to address problems previously mentioned. The corporation BioPower Systems have created a multitude of patents to construct and install the first BioWAVE, in Port Fairy, Victoria, Australia where it has full exposure to the Southern Ocean swell. This mechanism is a submerged structure mounted on the seafloor, with a pivot axis near the bottom. As the ocean water accelerates and decelerates around the cylinders with each wave, the structure responds by swaying back and forth. Hydraulic cylinders, mounted near the pivot, pressurise fluid within an enclosed hydraulic system. The high-pressure fluid is supplied to an O-Drive module, which converts wave energy into electricity which is transferred to shore via a subsea cable.
The BioWAVE design solves critical problems surrounding the use of wave energy on a large scale. It is a technology that uses biomimicry, which refer to the adaptation of biological traits in engineered systems. As a result, it has less of an impact on marine environments’, as it’s torque (or movement) about the pivot access flows with its surroundings rather than obstructing it. Therefore, it is less likely to alter patterns of coastal erosion and sediment on the seafloor. Moreover, unlike traditional wave farms which utilise a turbine with sharp blades that could potentially harm marine flora and fauna, the BioWAVE uses hydraulic cylinders to pressurise fluid to supply the O-Drive generator with wave energy to convert into electricity. BioWAVE is several stories high and has the ability to consistently produce up to 250kW of steady electrical power, roughly equivalent to about 200 houses. Although this doesn’t completely exploit the potential energy of waves, it provides a more consistent supply of electricity from that currently obtained from wind or solar power. The stream of electricity delivered to onshore consumers could be the considered near-baseload in many locations.
The socio-economic challenges present in current wave farm mechanisms, include the displacement of fishing or marine vegetable harvest grounds and the transit routes of commercial and recreation fisherman. In order to deal with these issues, BioPower Systems has set up lines of communication with key stakeholders as part of a “Community Consultation Plan”. The corporation holds meetings where stakeholders can address any issues for Port Fairy residents and marine users may be facing.
The Implication of Science
The current research being undertaken to develop the BioWAVE, has various disadvantages and advantages from environment and economical perspectives. In term of an economic perspective, the design of the wind farm is largely cost effective. One of the key challenges for other types of mechanisms is the cost associated with systems that are devised to become resistant to harsh elements in a marine environment. The BioWAVE is unique in that it is able to avoid this problem by laying the unit flat against the seabed during extreme wave events and storms. It has also been designed to have maximum modularity, meaning it can be installed with ease to an extend and requires only low-cost maintenance. Even with these advantages, there are still negatives from an economic stand point. The total project has been valued at $24.2 million, not taking into account the ongoing maintenance costs. The BioWAVE installed in in Port Fairy, Victoria, Australia was also only a prototype version of wave farms the BioPower Systems corporation intends to build. The next, which will incorporate experience and learnings from the BioWAVE pilot, is predicted to have an even more expensive initial cost.
Moreover, the BioPower Systems corporation has commissioned numerous studies in an attempt to minimise the negative impact it has on the environment. They began with an identification of local vegetation communities and threatened flora and fauna species. Habitats recorded offshore with an underwater camera were qualitatively described from the footage. At the device installation site, the only biota observed was drifting crayweed and no epibenthic biota (organisms living on the surface of sediments at the bottom of the sea), were found. A main advantage of the BioWAVE from an environmental stand point is that offshore marine communities will be largely unaffected. Additionally, a review of existing data for marine animals has been analysed to evaluate the potential interference caused by the BioWAVE. The study found out that there would to be virtually no noise pollution or acoustic impact on marine community behaviour, caused by the BioWAVE, as it is expected to emit near-zero noise underwater. No impacts with local buoys or moored vessels, suggest that there is a low probability of collision with small or large marine animals. There was also no indication of altered migration or behaviours in marine flora and fauna, due to the electromagnetic fields produced by the mechanism. This was consistent after the installation of the BioWAVE, as staff involved in the project attended a workshop from the Blue Whale Study Inc. for identifying and interpreting marine behaviour. No changes have been identified, although this form of post-installation monitoring is an ongoing process.
However, there are still concerns on the potential negative environmental impacts, specifically on native and endangered species of wildlife, when using this form of renewable energy on a large scale. A study was conducted involving the recording of present flora and fauna species, to evaluate the impacts of the BioWAVE project. It found three species of coastal bird along Taylor’s Beach that would be directly affected by onshore operations. This identification prompted adaptive management strategies for this process, specifically in cooperation with coastal bird conservation efforts. Isolation zones and protected measure were adopted, as per recommendation of Bird Life. Despite this, a hooded plover nest was identified on Taylor’s Beach during cable deployment.
Conclusion
To conclude, wave power has faced environmental, economic and socio-economic challenges including energy inefficiency, displacement of recreational and commercial fisherman as well as its potential negative impact on marine flora and fauna. Research to build technology like the BioWAVE are attempting to solve these problems through management strategies, such as isolation zones for coastal birds, as well as innovative design to minimise complications. Although wave power as a renewable energy source has its limitations, it is a vital step in building a more sustainable future.