**5. Conclusions**

The present work provides a general picture of the wind energy resources in the coastal environment of the Black Sea (onshore and offshore) ERA5 wind data that cover the 20-year time interval from January 2002 to December 2021.

Besides a general analysis of the wind resources at a hub height level (100 m), some specific analyses related to the wind energy were also performed. These include the distribution by wind classes, a multicriteria classification of the sites, evolution of the *VmaxE* indicator, and performance of a 20 MW wind turbine. Based on these results, we can conclude that the regional offshore wind resources are significantly stronger than onshore regardless of the coastal sector considered. Furthermore, it was also noticed that the wind conditions gradually increase from the land to the marine areas, with the mention that the sites located alongshore may present suitable conditions for the development of a wind project.

Looking now at the initial research questions formulated in the Introduction, the following answers can be provided:


It has to be also highlighted that the present work has some limitations, of which we can mention the use of the ERA5 wind dataset that is not real, observed data. On the other hand, the ERA5 dataset is considered to be some of the best reanalysis data available at this moment, being frequently used by scientists from various research fields. We need also to mention that there is currently no wind project where a 20 MW generator operates, but on a longer term, this is the philosophy promoted by the European Union that can be achieved throughout projects such as Mobil-Grid-CoP [45].

Finally, we can conclude that the Black Sea area represents an important wind energy source for the implementation of the European Green Deal strategy. From this perspective, a significant contribution is expected from the EU countries (Romania and Bulgaria) that

are defined by windy areas and shallow water regions, being possible to develop fixed and floating wind projects.

**Author Contributions:** V.Y. designed and wrote the manuscript. E.R. drafted and supervised the manuscript. F.O. analyzed the data and performed the interpretation of the results. The final manuscript has been approved by all authors. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was carried out in the framework of the research project DREAM (Dynamics of the REsources and technological Advance in harvesting Marine renewable energy), supported by the Romanian Executive Agency for Higher Education, Research, Development and Innovation Funding—UEFISCDI, grant number PN-III-P4-ID-PCE-2020-0008.

**Acknowledgments:** The results of this work will also be presented to the 10th edition of the Scientific Conference organized by the Doctoral Schools of "Dunărea de Jos" University of Galati (SCDS-UDJG) http://www.cssd-udjg.ugal.ro/ (accessed on 4 June 2022) that will be held on the 9–10 June 2022, in Galati, Romania. The data processed in this work are openly available. The ERA5 wind dataset is freely available through the EU-funded Copernicus Climate Change Service.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

