Good morning :)
similar to what Svenja said for Bayer, German is no requirement for working at E.ON Inhouse Consulting either. We have a lot of internationals with us, therefore we mostly speak English in the office anyway.
However, if for any reason a projects requires German, the staffing process takes individual language skills into account. Plus, ECON offers weekly German classes for internationals - which definitly is a plus for your personal development :)
Best
Patricia