Mention of the biogas register in the bill for the 2012 Renewable Energy Sources Act (EEG).

Explicit mention of the biogas register in the justification of the bill for the 2012 EEG:

Bundestags-Drucksache (Bundestag Publication) 341/11 , on p. 144 and 179:

EEG clearing committee

The EEG clearing committee explicitly mentions the German biogas register's suitability for mass balancing:

EEG clearing house: What is a mass balancing system? 

BDEW and electricity grid operators.

The German Association of Energy and Water Industries (BDEW) and German electricity grid operators recognise the biogas register as proof of record.

Publications of the BDEW on this topic: