I have not found the system adequately explained anywhere. It is notes denominated in euros. Are they 100% backed by euro notes stored in a warehouse? Probably not. 100% backed by a euro savings account? Probably not. Partially backed by a savings account? Probably not. This leaves only the possibility of them being a form of debt. Does the organization that issue them receive 100% payment from the users? Probably not, but if so, where are the money going? If the users does not pay for them, how are they distributed to the users? A certain amount per person? We don't know.
Anyway, being debt, the notes will have a value less than nominal. We have also seen from the newspaper reports they are not usable for all kinds of trade, for instance a doctors bill can only partly be paid with TEM's, the rest must be paid in euros. When the system is being wound down some time in the future, the holders will loose the value of their TEM's.
All in all, this experiment is not really interesting from a money system aspect.