1. Introduction
The transition towards a greener and more sustainable economy is one of the principal drivers of the current economic and political landscape, both nationally and at European level. Renewable gases will play a key role in reducing carbon emissions, particularly biomethane, whose characteristics promise to make it a central element in the decarbonisation process.
Both Law 7/2021 on Climate Change and Energy Transition and the Integrated National Energy and Climate Plan covering the period 2023–2030, approved by Royal Decree 986/2024 of 24 September, include references to the need for the Government to promote renewable gases, including biogas, biomethane and green hydrogen. Spain’s Biogas Roadmap, approved in March 2022, indicated that at least 1% of gas consumed through the natural gas network in 2030 would be biomethane. The Biogas Roadmap proposed instruments including annual targets, imposed through legal obligations on consumers, suppliers and producers, to ensure that a specified percentage or quota of gas injected into the grid derives from biogas.
Biomethane (CH₄) is a combustible gas obtained from biogas — a renewable gas composed mainly of methane and carbon dioxide, produced by the anaerobic (oxygen-free) degradation of organic waste. To produce biomethane, biogas generally undergoes a process known as ‘upgrading’, which removes certain impurities (e.g. CO₂), thereby increasing the methane content to around 95%. This level of purity allows it to be injected into the network alongside conventional natural gas, so that biomethane can serve as an alternative to natural gas for generating electricity and heat, as well as fuel for land, sea and even air transport.
Biomethane plants consist principally of the upgrading facility and the infrastructure for transporting the gas produced to the connection point on the gas network.
For logistical reasons, upgrading facilities are in most cases located alongside biogas plants. Consequently, it is very common for organic waste collection facilities, anaerobic digestion facilities (biogas plants) and upgrading facilities to be co-located on the same site. The biomethane produced is then injected into the gas network or distributed via dedicated pipelines to the end consumer.
Biomethane is one of the renewable gases that has seen the greatest expansion in recent years. By way of example, in 2021 there was only one biomethane plant in operation in Spain, whereas by early 2026 there were already 23, of which 21 were injecting biomethane into the gas network.
This article describes the main aspects of the regulatory framework, both current and being processed, applicable to biomethane in Spain.
2. Access to and connection to the gas network
In 2025, a significant milestone was reached with the approval of Circular 2/2025 of the National Commission for Markets and Competition (the “CNMC”), which establishes the methodology and conditions for access to, and allocation of capacity in, the natural gas system. This regulation recognises the titleholders of “other gases” production plants as new entities with the right of access to, and connection with, the gas network, granting them a series of rights in relation to connection applications and gas injection, together with corresponding obligations.
Article 12 bis of Royal Decree 1434/2002 of 27 December — which regulates the activities of transmission, distribution, trading, supply and authorisation procedures for natural gas facilities — regulates the connection of renewable gas production plants to transmission or distribution networks. This provision was inserted by Final Provision 12 of Royal Decree-Law 14/2022 of 1 August on economic sustainability measures in the field of transport, regarding scholarships and study grants, as well as measures for energy saving, energy efficiency and the reduction of energy dependence on natural gas.
Another important milestone is the CNMC Resolution of 13 June 2025, which establishes the procedure for managing applications and contracting the connection of “other gases” production plants to the natural gas transmission or distribution network. For the purposes of this procedure, “connection of a plant producing other gases to the natural gas network” is defined as the set of facilities strictly necessary to enable the injection of such gases into a gas system facility, excluding any direct line as defined in Article 78 of Law 34/1998 of 7 October on the hydrocarbons sector.
3. Environmental permits
In the environmental sphere, the following legislation applies to biomethane projects: Royal Legislative Decree 1/2016 of 16 December, approving the consolidated text of the Law on Integrated Pollution Prevention and Control; and Law 21/2013 of 9 December on Environmental Assessment. Under these regulations, biomethane production falls within the category of chemical facilities for the manufacture of inorganic chemical products, such as gases.
This type of facility is subject to an integrated pollution prevention and control authorisation (“IPPC Authorisation“) granted by the regional government department responsible for the environment in the autonomous region where the facility is located. The IPPC Authorisation consolidates a range of separate environmental authorisations relating to waste, air pollution and other matters.
4. Municipal and planning permissions
These facilities require the necessary municipal licences for their construction and subsequent operation, as well as the relevant planning permissions depending on the classification of the land on which they are located.
5. Substantive authorisations
Biomethane plants themselves do not require substantive administrative authorisations from the competent authorities in each region. However, this is an aspect that merits consideration to help complete the set of permits required for facilities of this type. In many cases, authorities are uncertain about what is or is not required for biomethane plants, and in our view this should be addressed by future regulation.
The direct lines associated with biomethane production plants do, however, require administrative authorisations for their construction and commissioning. These are granted by the regional ministry responsible for energy in the autonomous region where the facility is located, or by the central government where the evacuation infrastructure crosses more than one autonomous region. Isolated pipelines, discussed below, also require such administrative authorisations.
6. Direct lines and isolated pipelines
Biomethane production plants that connect directly to the gas network do so via direct lines. These are defined in Law 34/1998 of 7 October on the hydrocarbons sector as a gas pipeline complementary to the gas system, intended either for the exclusive supply of a consumer via a direct connection to the transmission network, or for the connection of a renewable gas production plant to the gas system for the purpose of injecting gas into it.
Direct lines connecting a renewable gas production plant to the gas system for the purpose of gas injection are excluded from planning requirements and are declared to be of public utility for the purposes of expropriation and the exercise of rights of way. Ownership of the direct line lies with the consumer or the producer of renewable gas.
Facilities that are not connected to the gas network may supply the gas produced via isolated pipelines. These are also declared to be of public utility for the purposes of expropriation and the exercise of rights of way, and do not require inclusion in the planning process.
7. Guarantees of origin
To incentivise the production of biomethane, a system of guarantees of origin (“GOs”) has been established to certify the renewable nature of the gas and its principal characteristics.
This system is regulated by Royal Decree 376/2022 of 17 May, which governs the sustainability criteria and greenhouse gas emission reduction criteria for biofuels, bioliquids and biomass fuels, as well as the system of GOs for renewable gases. It is further developed by Order TED/1026/2022 of 28 October and Order TED/728/2024. At present, three types of GO may be issued: (i) for biogas production; (ii) for renewable hydrogen production; and (iii) for the production of grid-compatible gases, such as biomethane.
In order to hold GOs, producers of renewable gases — as well as other entities that may be holders or operators of GOs (namely suppliers, consumers and “entities for registration purposes”, the latter being authorised entities that participate in the system solely to carry out transfers, exports or imports to other EU member states) — must register with the GO System. The Register of Renewable Gas Production Facilities includes all facilities that have been registered in this system.
8. Draft Royal Decree on the promotion of biomethane
At the time of writing (June 2026), a draft Royal Decree to promote biomethane is being processed. The public consultation process (submission of comments) concluded on 11 June 2026.
One of the key aspects regulated by this draft legislation is the establishment of minimum biomethane penetration quotas. The parties required to meet these quotas are: (a) suppliers, based on sales to their end customers in the domestic market over the course of a calendar year; and (b) direct market consumers, based on the volume consumed that has not been purchased from a supplier during that calendar year. Accordingly, those parties must consume or supply to their end customers a minimum quantity of certified biomethane (i.e. biomethane holding guarantees of origin for renewable gases) as follows: 0.5% in 2028; 1.1% in 2029; 1.8% in 2030; 2.5% in 2031; 3.3% in 2032; 4.1% in 2033; 5% in 2034; and 6% in 2035. These percentages apply to the total natural gas and liquefied natural gas consumed or supplied on the domestic market during the relevant calendar year. The following supply points are excluded from this total: (i) combined cycle power stations; (ii) supply points connected to manufactured gas distribution networks in island territories not connected to the gas pipeline network; (iii) supply points where the supply is used as fuel for land, sea or air transport; and (iv) cogeneration facilities. Obligated parties must submit an annual report to the Directorate-General for Energy Policy and Mines of the Ministry for the Ecological Transition and the Demographic Challenge (the “MITECO“) detailing the volume of certified biomethane consumed or supplied to their end customers. Failure to comply with biomethane penetration obligations is classified as a very severe infringement.
It is further established that, by a regulation to be issued by the MITECO, a requirement will be introduced stipulating that, in order to contribute to the fulfilment of these quotas, biomethane production plants that come into operation after the date on which the quotas take effect must hold the seal of social, territorial and environmental excellence set out in Royal Decree-Law 7/2026 of 20 March, approving the Comprehensive Plan for Responding to the Crisis in the Middle East.
With regard to direct lines, the draft provides that these shall comprise the pipeline for injecting gas into the network, located between the manhole or the site of the new or modified connection point on the existing gas pipeline (excluding the connection point itself) and the boundary of the land on which the plant is located. The producer may construct the direct line using its own resources or request its construction from the transmission or distribution operator of the network to which it connects. Upon commissioning, the direct line must be transferred free of charge to the transmission or distribution operator, who must accept the transfer. In this way, the facility is integrated into the gas system as part of the transmission or distribution network without incurring any investment remuneration payable by the gas system. The transmission or distribution operator is then responsible for its operation and maintenance.
Parties connecting subsequently to a transferred direct line must pay the parties who funded the construction of the original direct line the updated cost of the investment, in proportion to the length of the shared gas pipeline and the allocated connection flow rate.
Any new or modified point of connection required for the injection of renewable gas forms part of the transmission or distribution network into which it is injected. In the event of disputes regarding works relating to new or modified points of connection, or the connection of a direct line, these may be referred to the CNMC where the matter falls within the remit of the central government, or to the relevant competent body of the autonomous region.
Without prejudice to the regulation of further aspects, the draft provides that, within a maximum period of six months from the entry into force of the regulation, the Technical Management Regulations for the Gas System falling within the remit of the Ministry shall be drawn up. These regulations will set out the technical requirements, the configuration of the facilities and the implementation requirements applicable to direct lines for other gases, to the components located therein, to the points at which the direct line connects and to reverse flow equipment.
9. Conclusion
As this article demonstrates, there is clearly growing interest in biomethane projects in Spain. The Government has regulated several important aspects of this sector in recent years and now intends to approve a Royal Decree that will further advance the path already undertaken.