In Denmark the physical post offices have been closed since a few years (cost reduction). Even stamps aren't printed anymore (you have to pay online to get a code that you print or write on the letter or parcel).
There is something similar in France : "jours amende". The key point is that if you don't pay the fine, you go to prison the number of days indicated in the "jours amende". It's for criminal court, not for traffic infractions.
I'm wondering if there are similars laws in Germany ?
Can you be required to provide password for your mobile phone or computer by German police ?
I had the impression that they were more protective of personal informations in Germany but maybe I'm wrong.
Another way to produce sodium is by electrolysis of sea salt brine.
You need lots of power. A by-product is hydrogen chloride which is a bit dangerous to handle.
Pure sodium itself is also tricky: it reacts violently with water. Even humidity in air is enough to start a fire with pure sodium.
There's a company in France that uses electrolysis to produce metal sodium: Metaux Speciaux SA.
Also in France it has become very complicated to get a passport.
It takes months to get an appointment, and it's available only in few cities.
So if you can travel to other EU countries with just an ID card the choice is simple.