Study of the Wave Energy Propagation Patterns in the Western Black Sea

Eugen Rusu
2018 Applied Sciences  
The most relevant patterns of the wave energy propagation in the western side of the Black Sea were assessed in the present work. The emphasis was put on the western side because this is also the most energetic part of the Black Sea. The assessments performed relate some recent results provided by a numerical wave modeling system based on the spectrum concept. The SWAN model (acronym for Simulating Waves Nearshore) was considered. This was implemented over the entire sea basin and focused with
more » ... n and focused with increasing resolution in the geographical space towards the Romanian nearshore. Furthermore, some data assimilation techniques have also been implemented, such that the results provided are accurate and reliable. Special attention was paid to the high, but not extreme, winter wave energy conditions. The cases considered are focused on the coastal waves generated by distant storms, which means the local wind has not very high values in the targeted areas. This also takes into account the fact that the configuration of the environmental matrix in the Black Sea is currently subjected to significant changes mainly due to the climate change. From this perspective, the present work illustrates some of the most recent patterns of wave energy propagation in the western side of the Black Sea, considering eight different SWAN computational domains. According to most of the recent evaluations, the nearshore of the Black Sea is characterized by an average wave power lower than 6 kW/m. The results of the present work show that there is a real tendency of the wave energy enhancement. This tendency, especially concerns the western side of the basin, where in the high conditions considered, values of the wave power about 10 times greater than the average have been noticed. despite some initial difficulties related to the high cost of installation and operating conditions in the harsh marine environment, very high dynamics in increasing the efficiency of the offshore wind can be also noticed. This is measured, especially through the levelized cost of energy (LCOE), which reached a record value of about 7 c€/kWh in 2017, or less. Thus, 5.5 c€/kWh have been reported at the 700 MW Borssele (The Netherlands) due to government tender and size, and 5c €/kWh (without transmission) at the 600 MW Kriegers Flak (Denmark) [2] . This means the offshore wind becomes now not only the cheapest marine renewable energy resource, but it is also cheaper than some traditional resources. For example, the current average LCOE for atomic energy is still about 11 c€/kWh, or greater [3] . Various studies [4] [5] [6] [7] showed that the wind energy resources along the coasts of the Black Sea, and especially in its western side, are comparable with those from many offshore wind farms that are already operational [8] [9] [10] [11] . Thus, it is expected that the high dynamics of the offshore wind industry will have as a result also the implementation of some wind farm projects in the nearshore of the Black Sea, in general and in its western side, which is more energetic, in special. Furthermore, most of the studies [12] [13] [14] [15] indicate that the climate change will induce significant enhancements of the wind speed in the Mediterranean and Black Sea basins. On the other hand, although the potential of wave energy in the Black Sea is not comparable with that from the ocean [16] [17] [18] , the expected advances of the WEC (Wave Energy Converters) technologies may make this coastal environment interesting also for the implementation of the marine energy farms, especially as regards the hybrid wind-wave projects. Many coastal areas in the Black Sea are subjected to high erosion processes and the future nearshore farms can play an important role in the coastal protection, because they extract (or dissipate) part of the wave energy before the waves arriving to the shore [19] [20] [21] [22] [23] [24] . Furthermore, this is a general problem for many coastal environments and the marine energy farms, besides providing electricity, can become an effective solution in the struggle against the coastal erosion [25] [26] [27] . From this perspective, the present work has as a main objective to assess the most recent wave energy propagation patterns in the western side of the Black Sea. This considers also the fact that there is an obvious dynamics of the wave climate in the Black Sea having as a consequence important changes in the actual patterns of the nearshore wave propagation and inducing significant enhancements of the wave power. For this purpose, a wave modeling system based on the SWAN (Simulating Waves Nearshore) spectral model [28] has been implemented in the Black Sea basin and focused on the Romanian nearshore in a multilevel modeling system with increasing resolution towards the cost. Materials and Methods Theory of SWAN Spectral Model
doi:10.3390/app8060993 fatcat:wpxcpbyi6bgxtm4umolqpce7r4