## 5 Conclusions  
This work aimed to contribute to the digital transition in higher education by creating a standardized educational model based on remote laboratories focused on renewable energy and developed in an EU framework. The aim was to establish, test, and validate a standardized educational model and an ICT solution for conducting laboratory activities remotely, merging online and traditional learning and allowing students to carry out practical activities/experiments integrated with theoretical lessons on renewable energy topics. The collaborative European network consists of five European universities that have proposed to bridge the lack of common infrastructures between different remote laboratories. The result has been the creation of the REOPEN educational network. REOPEN offers real learning opportunities to a more diverse and broader engineering student body by providing more flexible access to physical experiments anytime, anywhere. With this collaborative infrastructure, REOPEN promotes the reuse of programming codes, avoiding the fragmentation caused using proprietary tools by each university. Thus, the REOPEN network provides students with the necessary competences to meet the needs of Industry 4.0. Initially, this work had the initial objective of interviewing at least 15 professors and 25 students from STEM faculties; 5 university staff such as laboratory technicians; and 5 business administrators for the mapping phase. In total, 57 professors' surveys and 142 students' surveys from STEM faculties, 13 surveys from university staff such as laboratory technicians, and 35 business administrators' surveys were obtained. The data obtained from the surveys show that the implementation of remote laboratories in the teaching-learning method is a real novelty. In general, students and professors think that the incorporation of this new method is very beneficial, especially for laboratory practices. These laboratories offer a great deal of flexibility and versatility, and both students and professors have a very positive assessment of these advantages, as they allow the experiment to be repeated as many times as the students require, reinforcing the theoretical concepts. Another very positive evaluation obtained from the surveys is that the collaborative network is based on renewable energies, adapting to the new European energy model. Above all, however, the idea of creating a collaborative network of remote laboratories with the participation of five European universities has received the most positive evaluation. This idea fills a gap that existed until now, allowing the development of new skills techniques and enabling students to broaden their theoretical and practical knowledge by being able to use more laboratories than only those that are available at their own university. Since COVID-19 arrived in 2020, it has been transforming people's lives. REOPEN is a project that was created to cover a need that was arising at that time to continue teaching, especially at a practical level, remotely for the safety of students and professors. Since then, the teaching-learning method has been adapting to this new situation, with online teaching, i.e., hybrid education, taking center stage. Therefore, more and more remote laboratories are being incorporated in universities, especially in universities related to the scientific-technological field. It can be said that this collaborative network of European remote laboratories is a pioneering approach to covering this new context, and in an emerging and booming field, such as renewable energies, which is a rather expensive field, not all universities can afford to have renewable energy-based laboratories inside their facilities. To conclude, it is convenient to discuss the limits of remote laboratories. These should not be perceived as a substitute for conventional labs (on-site) but as a complement and solution to their restrictions.