Technical standards for biomethane and natural gas

Until October 2011 there was no national agreement within the central government related authorities on the applicable legislation for biomethane injection into the grid. According to a detailed protocol for which the resolution was approved on 22nd September 2011, this is now permitted and regulated by the PD-01 on the norms for the technical management of the NG system. The electronic version can be consulted by following the next link:

After some time and different national discussions with national stakeholders, the specific requirements affecting the Oxygen limitation were modified via a specific Resolution dated on 21st December 2012, and raising the oxygen limit to 0,3 mol% under certain conditions. This additional Resolution can be found by following the next link

Requirements for gas quality

As stated in the above mentioned protocol PD-01, the NG transmission system users are completely responsible for the quality of the product delivered to the grid. In point 5.1.2. for Gas Quality, the specifications are set:

- General specifications:

- Biomethane specifications (additional to the general specs):

As explained above, and in the case of biomethane, a maximum oxygen content of 0,3 mol% is allowed only if:

- the total CO2 content is below 2 mol%
- water dew point is below -8ÂșC
- the total injected volume is below 5000 m3/h. For larger volumes additional specific negotiations shall be carried out

Grid access restrictions

Point 3.1. of the PD-01 protocol states the rights of access to the masurement installations and their verification

Point 3.2. states the rights of access to the telemetry information

Point 3.3. states the rights to install telemetry equipment

Point 4.2. states the points of the NG distribution system which must have gas quality analyzers

Point 4.4. states the specifications and characteristics of the measurement equipment

Point 4.5. states the specifications and characteristics of the gas analyzers

Point 5.1. states the reponsibilities of the different agents involved in the process, together with the measurement points, periodic maintenance, etc

Point 6 states the gas measurement requirements and associated procedures

Point 7 states the metrologic control of the measurement installations

Point 9 states the odorisation requirements


Lack of a strong fiscal incentive when compared to electricity production.