Industry4.0 and the IoT are the 4th Industrial Revolution (IIoT) which brings about changes in the way the economy works, opens new avenues for research and creates new employment opportunities in all scientific fields. IIoT is essential also to the Energy Systems. Various types of sensors and other types of technological equipment are used in energy systems. As a result, large volumes of data are generated which are transferred to a server for processing. The big challenge in this process is privacy and security when transferring data. In this regard, cybersecurity systems are very important to ensure the encryption of this data. An effective way to integrate verifiable credentials into data workflows is to build and deploy self-sovereign identity (SSI) solutions. Towards this direction, in the case study of the present work, we present a cybersecure framework which combines SSI for marine wind turbines that can be used in the Greek seas. For our system we suggest many sensors that will collect data and will be connected to an intelligent system that will decide according to the situations. To best of our knowledge this is the first study under this perspective, and we estimate that the proposed framework could potentially be used for the security of data generated by sensors above offshore wind turbines.