Why Biomethane is key to Spain's Energy Future

The total number of biomethane project plants in Europe increased from 1,548 to 1,678 between the 2024 and 2025 data collection periods, as shown in the most recent European Biomethane feed-in Map. During this period, 165 new plants began operating, 56 of which were already confirmed to be active by early 2025. This net growth reflects the steady expansion of a promising and sustainable sector.

In recent years, European farmers have made significant strides in reducing their environmental impact, increasingly turning to the production and consumption of renewable energy derived from naturally replenished sources. Although rural areas offer substantial opportunities for generating clean energy — through access to wind, solar power, bio natural gas, and agricultural residues — significant barriers still hinder full-scale deployment. Bio-LNG (biologically-derived Liquefied Natural Gas) and CNG (Compressed Natural Gas) are emerging as important low-carbon alternatives for transport in rural and urban settings.

Among renewable energies, biogas production is distinguished by its capacity to simultaneously address multiple environmental and socio-economic objectives through a single technological pathway. Anaerobic digestion enables the conversion of organic waste from agricultural, agri-food, and urban sectors into renewable energy, while simultaneously mitigating methane emissions and promoting nutrient recycling via the agronomic use of digestate. This integrated approach not only aids decarbonization but also strengthens circular economy models and revitalizes rural economies. Biomethane processing, as an upgraded form of biogas, offers a near carbon-neutral energy vector, achieving more than a 90% reduction in greenhouse gas emissions compared to conventional fossil fuels. Additionally, LNG produced from biomethane can substitute conventional fossil LNG in heavy-duty transport.

Strategic Role and National Planning

Spain faces the challenge of transforming its energy system to reach climate neutrality by 2050. Biogas production and biomethane feed-in, as renewable gases, are poised to play a crucial role in achieving emission reduction and renewable energy penetration targets — particularly in the transport sector. Recent research confirms that biomethane project is an effective tool for cutting transport-related greenhouse gas emissions, which represent around 25% of the EU's total emissions. The Biogas Roadmap from MITECO emphasizes that its development promotes synergies between the circular economy, a just energy transition, and the demographic challenge.

Aligned with the European strategic framework, the Spanish Circular Economy Strategy ("España Circular 2030") sets a goal of reducing waste generation by 15% compared to 2010 levels. It also outlines strategic guidelines for the effective application of the waste hierarchy, an area where biogas production technologies can play a pivotal role — particularly in managing biowaste. Converting organic fractions into energy and valuable byproducts reduces methane emissions from landfilling and supports material recovery, especially in the agri-food and urban sectors.

Current Situation in Spain

The global energy transition has become an unavoidable priority to limit the increase in average global temperature to below 2 °C, as established by the Paris Agreement. This international commitment requires profound transformations in the current energy model — changes that are still not fully captured in most existing energy scenarios. Shifting away from fossil fuels toward low-carbon alternatives is essential, given that CO₂ emissions from energy use account for approximately two-thirds of all global greenhouse gas emissions. Within this context, Spain must accelerate its energy transition through sustainable technologies such as biogas production and biomethane processing.

According to the 2024 EBA Statistical Report, Spain currently has 15 operational biomethane plants — far fewer than countries such as France or Germany. Despite an estimated technical potential of up to 163 TWh, only a small portion is currently being utilized. Spain's Integrated National Energy and Climate Plan (PNIEC) has set a goal of reaching 20 TWh by 2030, which will require increasing current production more than elevenfold. Law 7/2021 on Climate Change and Energy Transition, along with the 2023–2030 PNIEC, includes renewable gases as essential tools for decarbonization, yet their effective deployment depends on accelerating regulatory development.

Although Spain's revised feed-in target for biomethane doubles the previous targets, its share of the national energy mix remains modest, currently accounting for just over 6% of Spain's annual gas consumption. Compared with the progress seen in other European countries, this figure appears insufficient. On the other hand, Spain achieved a record high in renewable electricity generation in 2024, with 57% of all electricity consumed in the country coming from renewable sources — an important milestone in the evolution of its energy mix. Spain holds considerable potential to scale up biomethane production, with estimates suggesting it could eventually substitute up to 40% of natural gas demand through domestic resources. Bio-LNG and LNG could play a complementary role in substituting fossil fuels in industrial and transport applications.

Environmental Impacts: The Nitrogen Challenge

Biomethane processing is not without its environmental challenges. Among them is the consistent supply of feedstock to biogas plants and the potential rise in transport volumes, which may increase traffic and emissions linked to feedstock logistics. These issues, among others, have raised concerns about the environmental compatibility of large-scale biogas production. The entire biogas production system entails material and energy inputs — ranging from feedstock supply chains to plant operations, biogas utilization, and digestate handling. For this reason, integrated environmental assessments of biogas deployment pathways are essential to identify opportunities for improving overall sustainability.

Anaerobic digestion of organic waste generates digestate, a nutrient-rich byproduct containing high levels of nitrogen. Its application as an organic fertilizer can enhance agronomic efficiency, but if not managed properly, it may result in nitrate leaching, ammonia (NH₃) emissions, and nitrous oxide (N₂O) release — each posing risks to groundwater, air quality, and climate stability. Recent studies emphasize that nitrogen management is a key variable in achieving a truly sustainable biogas model.

Biogas plant developers and researchers are increasingly aware of the need for cleaner production and utilization pathways, and they are adopting environmental impact mitigation strategies based on lifecycle assessment (LCA) methods. Today, biogas system performance is subject to more rigorous evaluation, focusing on energy efficiency and environmental footprint. Detailed analyses are being conducted using multiple feedstocks and conversion scenarios, including digestate treatment and biomethane upgrading.

Modern biogas and biomethane facilities present minimal environmental risks: they are designed to be safe, emit low levels of pollutants and odors, and are often equipped with catalysts that convert NOx to N₂ and oxidize CO to CO₂. However, digestate management remains one of the most critical environmental issues. If not handled properly, the nitrogen content in digestate can contribute to ammonia emissions and nitrate leaching, exacerbating eutrophication and threatening groundwater quality. In intensive livestock regions or areas with limited land absorption capacity — such as parts of northern Spain — these challenges may hinder sectoral expansion.

Diffuse methane emissions during feedstock handling, storage, or upgrading can also compromise the net climate benefits of biomethane if not tightly controlled. On the social side, local opposition may arise due to concerns over odor, waste transport, or landscape impacts — factors that may delay project implementation, especially in rural areas with limited public awareness.

Technical Solutions and Why the Benefits Outweigh the Risks

Nonetheless, technological and regulatory advancements are helping overcome many of these challenges. The adoption of closed and covered systems for digestate storage, precise methane leakage detection through sensors, and the implementation of environmental protocols during plant operations have all significantly reduced the environmental footprint.

Nitrogen-related impacts, in particular, are being addressed through several innovative approaches: digestate acidification to reduce ammonia volatilization during storage, direct soil injection using specialized equipment, and the deployment of phase separation and nitrogen treatment systems to produce more controlled fertilizer products. Furthermore, integrated nutrient management plans are being promoted in livestock operations, and agronomic criteria and application limits are increasingly incorporated into environmental and fertilization regulations.

In this context, the recovery of organic waste through biogas production enables the valorization of previously underutilized or problematic resources. Technologies such as ammonia stripping allow for nitrogen reduction in digestate and recovery in the form of value-added fertilizers like ammonium sulfate. Other enhancements — such as co-digestion, biological digestate treatment, and the use of membrane separation or adsorption for biomethane purification — are boosting process efficiency while minimizing environmental impacts.

Despite these technical hurdles, it is important to emphasize that the benefits clearly outweigh the risks. Digestate used as fertilizer replaces synthetic alternatives with higher carbon footprints, closes nutrient loops, reduces methane emissions from traditional manure management, and supports the economic resilience of farming operations. In regions with robust circular economy policies, such as Cataluña and Castilla y León, these practices are being integrated into broader sustainable biogas models.

Public Engagement and Strategic Positioning

From a social perspective within the renewable energy context, incorporating citizen perspectives, local feedback, and iterative governance models can improve public acceptance, long-term effectiveness, and social equity in the energy transition. Participatory engagement builds trust and strengthens the legitimacy of decision-making processes, promoting a fairer distribution of benefits, especially for vulnerable communities.

To this end, community involvement strategies, transparent communication, and shared local benefits (such as job creation or cogeneration services) are improving social acceptance of biogas infrastructure. On balance, the benefits of biomethane deployment clearly exceed the risks: it enhances energy security, supports decarbonization of hard-to-abate sectors such as heavy transport, and valorizes organic waste within a circular economy framework.

In countries like Spain, where the availability of organic waste is high, biomethane systems present a compelling environmental and economic opportunity with significant growth potential. The sector is also socially promising, as it addresses several pressing needs, including sustainable waste management, emissions reduction, job creation, and energy self-sufficiency.

As at February 2026