It's interesting that the conversation of using badges in Europe leads to the value and translation of badges across countries, which is something that has come up in the US for transferring badges across institutions. However, the language barriers and educational differences across Europe does lead to a new set of issues. The European Qualifications Framework (EQF) was developed for formal degrees and certifications, but hasn't been applied to badges, yet. It might be an interesting place to start, since most countries, including several in the Unique Learning Badges network have aligned their own QFs to the EQF for transferability already.
(They are connected to the Unique Network, which is an online community that focuses on innovation and quality in education across Europe. )