The study enhances the coastal resource knowledge and discusses opportunities for wave energy in the Aegean Sea. A fine-resolution numerical wave model is utilised to provide results for the Greek coastal regions. The model ran for 35 years (1980-2014) estimating wave characteristics, and quantifying the wave energy potential in coastal areas. The results deliver the energy potential, variability, and site characterisation for the Aegean Sea. The dataset is coupled with wave energy converters power matrices to provide for the first time a long-term analysis of expected power production. Performance of devices is highly dependent on matching the power matrix to the local resource, suitable devices can obtain capacity factor up to 20% and favour operation for low wave heights and high frequencies. Based on energy analysis data, an economic performance and payback period of a hypothetical wave farm is examined. With little information on wave energy in the region, this preliminary cost-to-benefit analysis shows the viability of wave converters. Even with high capital expenditure associated with novel technologies, certain scenarios achieve amortisation periods at 7.5 years for a properly selected converter. Results are comparable with previous renewable schemes aimed at increasing the cumulative installation of other early stage technologies.

Over recent decades, the exploitation of wave energy resources has sparked a wide range of technologies dedicated to capturing the available power with maximum efficiency, reduced costs, and minimum environmental impacts. These different objectives are fundamental to guarantee the development of the marine wave energy sector, but require also refined assessments of available resource and expected generated power to optimize devices designs and locations. We reviewed here the most recent resource characterizations starting from (i) investigations based on available observations (in situ and satellite) and hindcast databases to (ii) refined numerical simulations specifically dedicated to wave power assessments. After an overall description of formulations and energy metrics adopted in resource characterization, we exhibited the benefits, limitations and potential of the different methods discussing results obtained in the most energetic locations around the world. Particular attention was dedicated to uncertainties in the assessment of the available and expected powers associated with wave–climate temporal variability, physical processes (such as wave–current interactions), model implementation and energy extraction. This up-to-date review provided original methods complementing the standard technical specifications liable to feed advanced wave energy resource assessment.

Thermal cycling is one of the major reasons for failure in power electronic converters. For submerged tidal turbine converters investigating this failure mode is critical in improving the reliability, and minimizing the cost of energy from tidal turbines. This paper considers a submerged tidal turbine converter which is passively cooled by seawater, and where the turbine has fixed-pitch blades. In this respect, this study is different from similar studies on wind turbine converters, which are mostly cooled by active methods, and where turbines are mostly pitch controlled. The main goal is to quantify the impact of surface waves and turbulence in tidal stream velocity on the lifetime of the converter IGBT (insulated gate bipolar transistor) modules. The lifetime model of the IGBT modules is based on the accumulation of fatigue due to thermal cycling. Results indicate that turbulence and surface waves can have a significant impact on the lifetime of the IGBT modules. Furthermore, to accelerate the speed of the lifetime calculation, this paper uses a modified approach by dividing the thermal models into low and high frequency models. The final calculated lifetime values suggest that relying on passive cooling could be adequate for the tidal converters as far as thermal cycling is concerned.

Significant advancements have been made in the past few decades (since the 1980s) on detailed evaluation and quantification of wave resources globally. Larger availability and advances of computational resources have contributed to the utilisation of numerical wave models as powerful tools in climatic and energy studies. This review presents current state-of-the-art numerical tools and their status in the process of wave power assessments. We focus on the evolution of studies undertaken at the European coastline regions and the Black Sea.Although, a number of studies have been successfully developed and implemented in the past contributing to our understanding of the resource, this paper discusses the benefits, limitations and potential for improvement of numerical tools. From the literature, it is evident that different applications and scale may require different models, however, it is also the experience and knowledge of the user, applied in the tuning of a number of parameters that govern the process of wave generation, propagation, and the quality of input parameters that are the cornerstones of a successful model. This review depicted that the use of numerical wave models, depending on specific region and application, offers significant benefits on quantification of coastal zone wave resources which benefit multiple offshore applications and the energy industry.

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