The biomethane producer registers the biomethane he injects into the natural gas grid. An environmental verifier or other expert (auditor) inspects the plant and production on site and confirms the quantity, property profile and origin of the biomethane in the register. Producers and intermediaries transfer the biomethane quantities purchased to the accounts of other registry participants according to the supply chain. The consumer withdraws the biomethane from the natural gas grid and books out the corresponding quantity from the register himself or with the help of his supplier. When the biomethane is withdrawn from the register, the consumer receives an extract from the register showing the consumed quantity with its origin, property profile and feed-in and withdrawal information. The consumer can then use this to apply for statutory refunds and compensation.
In order to be able to use the biogas register, a plant audit must first be carried out by an environmental assessor. This verifies the compliant production of the biomethane on the basis of various criteria. If all criteria are fulfilled, the biomethane producer can start to enter biogas quantities into the biogas register.
To verify the quantities and the quality of the biomethane, another audit is carried out, usually covering the annual biomethane quantities produced by the plant. The report is uploaded to the biogas register and checked by dena register management for consistency with the biomethane producers' data. After approval by dena, the biomethane can be consumed: The consumer is entered in the biogas register and the register extract is produced. This provides the end consumer with secure and traceable proof of the biomethane he uses.
Requirements and documentation times
In order to meet the requirements of the Renewable Energy Sources Act and the Renewable Energies Heat Act, the respective quantity of biomethane must be fully documented within the scope of mass balancing, from its production (start of mass balancing) to its injection into the natural gas grid and its transport in the natural gas grid to its withdrawal from the natural gas grid (end of mass balancing). A distinction is made between three documentation points in time:
Start of mass balancing
The first mass balance documentation shall take place at the handover of the biomethane from the connectee to the shipper for injection into the natural gas grid at the grid connection within the meaning of § 32 number 2 GasNZV.
The numerically correct transfer of the quantity of biomethane handed over to the shipper at the grid connection in a certain period of time is confirmed within the biogas register by an auditor after the so-called "booking-in" of the biomethane quantity. In addition, an audit document / audit opinion is deposited within the register to document the mass balancing.
Trading within the natural gas grid
Each transfer of the entitlement to exit a quantity of gas corresponding to the quantity of biomethane transported in the natural gas grid must be documented in terms of mass balance. This applies in particular to cases of trading in biomethane products at the virtual trading point.
This requires the documentation of the transfer of rights from the previous right holder to the new right holder. The documentation must present in a comprehensible form the parties involved in the transfer of rights as well as the volume of the respective quantity of biomethane (e.g. on the basis of its heat equivalent) at which the rights are transferred from the previous rights holder to the new rights holder.
Within the Biogas Register Germany, both the biomethane quantity and the new right holder ("buyer") are documented in a comprehensible form during the so-called "transfer". In addition, the previous right holder ("seller") makes a self-declaration that the same quantity of biomethane has only been transferred once (exclusion of multiple marketing).
Withdrawal of the gas from the natural gas grid at the point of withdrawal.
The obligation for mass balancing ends with the recording of quantities at the withdrawal point from the natural gas grid. This can be documented for the proof of mass balancing vis-à-vis the electricity grid operator or the competent authority via an extract from an independent database, provided that this extract confirms the quantity of biomethane withdrawn from the database and is linked to a documentation of the actual physically withdrawn quantity of biomethane by means of corresponding invoices, results of calibrated meters or comparable documents.
Within the Biogas Register Germany, a biogas register extract is generated during the so-called "derecognition", which documents the biomethane quantity both in terms of its remuneration and verification-relevant properties and in terms of its mass balance properties.
This biogas register extract can thus be used as proof of mass balancing for electricity grid operators or the competent authorities and as an auxiliary instrument for obtaining remuneration statuses or for the recognition of verification statuses.