The biomethane producer enters the biomethane it feeds into the natural gas grid into the register. 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 purchased biomethane quantities to the accounts of other register participants in accordance with the supply chain. The consumer withdraws the biomethane from the natural gas grid and books the corresponding quantity out of the register itself or with the help of its supplier. Upon deregistration, the consumer receives a register statement on the quantity consumed with the origin, property profile and feed-in and withdrawal information. The consumer can then use this to apply for statutory refunds and payments.
In order to be able to use the biogas register, a plant audit must first be carried out by an environmental verifier. This verifies the compliant production of the biomethane based on various criteria. If all criteria are met, the biomethane producer can start entering biogas quantities in the biogas register.
To verify the quantities and quality of the biomethane, a further audit is carried out, which normally covers the annual quantities of biomethane produced by the plant. The audit is uploaded to the biogas register and checked by the dena register management for consistency with the biomethane producer's data. Once approved by dena, the biomethane can be consumed: The consumer is entered in the biogas register and the register extract is created. This provides the end consumer with reliable and traceable proof of the biomethane they have used.
Requirements and documentation dates
In order to meet the requirements of the EEG and EEWärmeG, the respective quantity of biomethane must be fully documented from its production (start of mass balancing) to its injection into the natural gas grid and its transportation in the natural gas grid to its withdrawal from the natural gas grid (end of mass balancing) as part of mass balancing. A distinction is made between three documentation points in time:
Start of mass balancing
The first mass balancing documentation should take place when the biomethane is transferred from the connecting party to the shipper for injection into the natural gas grid at the grid connection within the meaning of section 32 number 2 GasNZV. The numerically correct transfer of the quantity of biomethane transferred to the shipper at the grid connection in a specific period is confirmed within the biogas register by an auditor after the biomethane quantity has been “booked in”. In addition, an audit document/audit report is stored in the register to document the mass balancing.
Trading within the natural gas grid
Each transfer of the entitlement to withdraw 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 with biomethane products at the virtual trading point. This requires documentation of the transfer of rights from the previous rights holder to the new rights holder. The documentation must show in a comprehensible form the parties involved in the transfer of rights and the volume of biomethane (e.g. based on its heat equivalent) for which the rights are transferred from the previous rights holder to the new rights holder. Within the German Biogasregister, both the biomethane quantity and the new holder of rights (“buyer”) are documented in a comprehensible form during the so-called “transfer”. In addition, the previous holder of rights (“seller”) makes a self-declaration that the same quantity of biomethane has only been transferred once (exclusion of multiple marketing).
Withdrawal of gas from the natural gas network at the withdrawal point
The obligation for mass balancing ends when the quantity is recorded at the withdrawal point from the natural gas grid. This can be documented for proof of mass balancing to the electricity grid operator or the competent authority by means of an extract from an independent database, provided that this extract confirms the quantity of biomethane booked out of the database and is linked to documentation of the quantity of biomethane actually physically withdrawn on the basis of corresponding invoices, results of calibrated meters or comparable documents. Within the German Biogasregister, a Biogasregister extract is generated during the so-called “deregistration”, which documents the biomethane quantity with regard to its remuneration and verification-relevant properties as well as its mass balance properties. This Biogasregister excerpt can therefore be used as proof of mass balancing and as an auxiliary instrument for obtaining remuneration statuses or for the recognition of verification statuses vis-à-vis electricity grid operators or the responsible authorities.
