On 22 May 2026, the Spanish Ministry for the Ecological Transition and the Demographic Challenge (MITECO) opened the public consultation on the Draft Royal Decree to promote biomethane, a regulation that for the first time introduces in Spain mandatory minimum quotas of renewable gas in the retail supply of natural gas. The path is progressive: 0.5% in 2028, 1.8% in 2030 and up to 6% in 2035, according to the figures reported by RETEMA. A figure equivalent to some 10 TWh of biomethane per year at the end of the period, a sevenfold increase on the capacity currently in operation in the country. Biomethane in Catalonia and Spain: growth strategies
For gas-intensive industries and gas retailers, the question is no longer whether biomethane will enter their energy mix, but how to manage its mandatory arrival. From our perspective as consultants, there are three readings of the decree that need to be made now, before the public consultation closes on 11 June and the regulation enters into force.
First reading: biomethane is no longer a voluntary asset
Until now, biomethane procurement was a voluntary strategic decision for companies with decarbonisation ambitions or under ESG pressure. Biomethane: Financial asset behind thermal decarbonisation
With the new decree, it becomes a regulatory obligation with a fixed timetable. Gas retailers will have to demonstrate compliance through Guarantees of Origin, and the quota will inevitably be passed on to the final bill of industrial customers, especially those that are not exempt (combined-cycle power generation, cogeneration, island territories and transport are excluded).
The practical consequence is that all industries with significant natural gas consumption will face a growing structural extra cost between 2028 and 2035. The difference between the companies that manage it well and those that do not will be set by their ability to get ahead on supply contracts and to find formulas that minimise the cost of compliance.
Second reading: there is a window of opportunity to sign early
This is a particularly relevant reading for industry. The Spanish market will go from the current 1.4 TWh to 10 TWh in 2035. This growth will be neither linear nor orderly: there will be supply tensions, especially between 2028 and 2031, while the pipeline of new plants is rolled out to absorb the mandated demand.
Companies that sign long-term supply contracts now —whether directly with producers through biomethane PPAs, or with specialist retailers— will secure more stable reference prices. Those that wait until 2027-2028 will negotiate in an already tight market. It is a pattern we have already seen with renewable power PPAs: the first movers captured margins; the last ones pay a late-entry premium.
Third reading: the Guarantee of Origin is no minor detail
The decree establishes that compliance will be demonstrated through the biomethane Guarantee of Origin (GO). This may look like an administrative formality, but it actually opens up three substantive technical questions that must be resolved before signing anything:
Geographic traceability: it will be necessary to define whether GOs from other European countries are accepted or only national ones. The answer will determine price and availability.
Compatibility with other schemes: many industrial companies are already using biomethane through certificates from other mechanisms (GHG reporting systems, voluntary schemes). Double counting will have to be avoided and reporting aligned.
Socio-environmental excellence label: the Royal Decree-Law 7/2026 provides for a new label that will assess the territorial, environmental and social sustainability of plants. Producers holding it could generate GOs with a quality premium —and therefore attractive to companies with strong ESG commitments.
What we recommend doing now
Given this scenario, we recommend four immediate actions to gas-intensive industries and gas retailers:
- Quantify the exposure: calculate the economic cost of compliance for each year of the trajectory, based on current consumption and biomethane price scenarios.
- Review existing contracts: identify renegotiation windows and clauses on the pass-through of regulatory extra costs.
- Explore PPAs and long-term contracts with domestic producers or specialist retailers, taking advantage of current prices ahead of the expected market tightness.
- Take part in the public consultation until 11 June, particularly to refine aspects of the GO and the exemptions affecting specific sectors.
At auma auma we support developers, industrial companies, utilities and administrations in this type of analysis: from modelling the economic impact and supporting procurement on the demand side, to environmental studies and permitting for new biomethane plants on the supply side. Biomethane is no longer an option reserved for pioneers. From 2028 it will be a tangible obligation to be managed with the same rigour as any other strategic energy vector. Biogas and Biomethane: the keys to decarbonisation