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By Charalambos Frantzis
The most important matter of the 21st century is perhaps climate change, due to the significant increase in humanity’s energy consumption.
Considering that the needs in energy will continue increasing significantly, the only way to limit the negative consequences on the environment, and therefore humanity, is the exploitation of every kind of renewable energy resource.
Among all forms of renewable energy resources, the least popular and exploited one is so-called «Blue Energy».
«Blue Energy» is defined as every kind of energy that is produced in the sea/ocean environment, such as wave, tidal, energy from ocean currents, and also offshore wind and solar energy.
Some 71% of our planet’s surface is covered by oceans; thus, the ocean environment becomes a vast source consisting of different forms of renewable energy, having the potential to play a catalytic role in limiting the energy and environmental problems of our planet.
The total amount of available wave power that can be exploited is 3 Terra Watts (TW), which exceeds the required power to cover the global needs of electricity (2.3 TW). Wave energy can also be predicted days earlier, in contrast to wind energy.
Taking this advantage into account, wave energy becomes attractive for the regulation of electricity production.
However, its exploitation is disproportionately low compared to wind and solar energy, even though they have lower potential.
The primary reason for this failure might be the lack of understanding and perception of the wave’s behaviour, which is responsible for the type diversity and numerous wave energy converter (WEC) devices that have been developed and studied.
Moreover, the various challenges that must be tackled by the WEC developers and inventors are burdens to the evolution of this sector.
The operation in the sea environment is a significant challenge on its own since the integrity of the device should be secured in extreme weather conditions.
Other important challenges are the installation and operation in large depths, accessibility of the device, maintenance conditions, and transport of the useful produced energy to shore where it can be distributed to the consumers.
An additional drawback of the existing WEC devices is their inability to efficiently operate in small wave heights, limiting their application in a few specific locations, where the wave conditions allow.
All these parameters lead to a huge cost for the construction and operation of WEC devices, resulting in non-financially viable projects.
Experts in research and development of WEC devices point out that these technologies are now at an early stage, similarly to wind energy technologies 30 years ago.
After several years of research and investment in this sector though, wind energy technology has reached an optimum design and is one of the most evolving economies in the field of energy today, exceeding 4% of global electricity production.
As far as wave energy is concerned, multiple difficulties and failures led to a significant reduction of investments in the field of research, from both the public sector and private companies, resulting in a rather slow evolution of the wave energy sector.
The «Blue» energy future of Cyprus
Evaluating the conditions in Cyprus, one could perhaps conclude that it is not worth investing in the sector of wave energy since the existing devices require considerably larger wave heights to start operating.
However, using the same mindset, one can claim that the investment in wind energy should have not been made as wind power potential in Cyprus is significantly lower than that of other regions of the planet.
Nevertheless, wind energy in Cyprus represents almost 5% of the total electricity production, while its contribution continues to increase.
As far as solar energy is concerned, which is supposedly an ideal solution for Cyprus, it contributes to the total electricity production half the amount of wind energy does.
A critical limitation for the use of these two technologies in the case of Cyprus is the need for large land area.
Therefore, to further install such technologies and reach a sustainable energy model in Cyprus, it is necessary to extend implementation in the sea environment.
The increased cost that is required to set up facilities in the sea, as well as the additional ones that are needed to support these devices, such as electricity transport cables, lead to a financial analysis with negative outcome when these devices are investigated separately and independently.
One way to achieve the financial viability of a project for exploitation of the island’s «Blue Energy», could be the coexistence of different devices that convert wave, wind and solar energy in the sea environment, achieving the co-utilisation of facilities and electricity transport networks.
Taking into account that wind and solar energy technologies have matured for land operation, the research should mainly move towards confronting challenges of operating in the sea environment.
Beyond these difficulties, research for the development and optimisation of WEC devices, which are at a very early stage, is of vital importance to complete the “puzzle” of the financial viability and the energy independence of Cyprus.
After a brief review of the existing technologies of wave energy, these devices cannot be used in Cyprus because of the weak wave conditions that prevail.
Nonetheless, a Cypriot inventor, Adamos Zakheos, CEO Sea Wave Energy Ltd (SWEL) Cyprus, has designed and constructed a WEC device, the Waveline Magnet, which can also work in the smallest wave heights that occur in the Cyprus sea.
According to Zakheos, “Other devices fail because they try to interact with the waves violently, to absorb larger amounts of energy”.
“On the contrary, the Waveline Magnet device cooperates smoothly with the waves and adjusts according to the desired sea state, achieving high energy absorption efficiency as well.”
The Waveline Magnet, which consists of an array of flexible parts that connect and operate in absolute collaboration with each other, operates on the sea surface and not below it, leading to easier maintenance and consequently cheaper.
Another important advantage of this device is the low cost required for its construction, installation and decommission procedures.
This is a result of its low weight and the simple construction of the individual parts, as well as the assembly device as well.
Moreover, the fact it can be constructed almost completely by recyclable materials reduces the cost and negative environmental impact as well.
Also, the Waveline Magnet does not use any kind of oil that can be harmful to the environment. It only uses seawater, which is pumped and can be used for electricity production or can be directly used for its desalination.
Considering that Cyprus has to increase the use of renewable energy resources and the needs for desalinated water will significantly increase, turning towards «Blue Energy» might be inevitable.
The utilisation of efficient WEC devices with the characteristics of the Waveline Magnet seems to be a very attractive solution for developing a complete and financially viable «Blue Energy» model, not only for Cyprus but also for the entire wave energy sector.
The writer is PhD Student Department of Mechanical and Manufacturing Engineering, University of Cyprus
