The feedback of the reviewers is proccessed in the new version:
-explanaition of the concept of open badges is added in paragraph 2.1 including references
-the typical length/duration of the trainings is addressed in paragraph 2.1.
- the introduction is adjusted regarding the explanation of the energy consumption as remarked
-paper is checked regarding the full write out
-full stop is added in the methodology at the end of the first paragraph
-the certification with open badges is explained in paragraph 2.1