In recent months, the debate surrounding biogas plants has intensified in several Spanish regions, highlighting both the environmental potential of this technology and the social and community concerns that its expansion brings. These projects, which aim to transform organic waste into renewable energy and fertilizers, have become the focus of controversy, protests, and even crises in municipal governments.
The biogas sector is advancing rapidly, driven in part by European funds and decarbonization policies. However, not everyone agrees on the benefits and implementation of these projects, and citizen mobilizations and political debates have emerged demanding greater transparency, participation, and a rethinking of some business models.
Growth of biogas plants and social reactions in Spain
Several towns have recently seen protests against new biogas plants, most notably Colmenar Viejo and Tres Cantos, against a large-scale project promoted by Enagás and PreZero. Under the slogan "Not so big, not so close," neighborhood associations and platforms like STOP Biogas Plant Colmenar Viejo-Tres Cantos have organized marches and presented legal alternatives to halt the declaration of public interest and the plant's construction.
The main concerns center on the proximity of the facility to residential areas and schools—some homes are only 300 meters away —the potential impact of polluting emissions and odors , and the lack of information provided during the permitting process. Residents complain that recommended buffer zones were not respected and that the entire process lacked transparency, generating deep distrust of the developers and municipal authorities.
In the north, in places like La Rioja , objections have also been filed by entities such as the Rioja DOCa Regulatory Council, concerned about the landscape and environmental impact of up to five plants under study, often close to vineyard areas.
In the province of Segovia , United Left denounces a speculative expansion of biogas projects that, according to their criticism, respond more to the interests of large companies and investment funds than to rural sustainability, also pointing out risks due to truck traffic, waste management and the possible contribution to depopulation.
Political conflicts and institutional crises over biogas
The growth of this sector has triggered situations of high political and even institutional tension, as has occurred in the municipality of Azlor (Huesca), where the project for a new biogas plant has caused chain of resignations within the city councilThe main reason: neighborhood discontent and the perception of opaque or rushed processing.
The mayor has acknowledged that the climate of mistrust created is preventing the continuation of municipal management as it has been doing and attributes the crisis to differences over the appropriateness and method of implementing the plant.
In the case of Colmenar Viejo, the recent approval of a motion to reconsider the declaration of public utility has been a moral victory for the residents' platform, although the final decision will depend on an extraordinary plenary session and the legal avenues already pursued. The mayor and the local government insist that the steps taken are legally sound and that the plant is key to the energy transition in the region.
In Galicia, the parliamentary debate on the regulation of biogas and biomethane plants has been intense, with citizen protests in front of Parliament and divergent positions between parties on the need to reconcile the expansion of the sector with rigorous territorial planning adapted to the local reality.
Environmental and economic advantages of biogas
Beyond the social conflict, biogas proponents emphasize its environmental and economic benefits . The plants transform organic waste into biomethane, which can power homes and industries, as well as generate organic fertilizers for agriculture, contributing to the circular economy. According to their promoters, these facilities allow for savings in waste management and reduce dependence on fossil fuels.
Projects like the one in Colmenar Viejo are expected to produce up to 60 GWh of renewable energy annually , enough to meet the needs of tens of thousands of people and prevent the emission of thousands of tons of CO2 each year. Furthermore, the plant includes advanced biofiltration systems and sensors to minimize odors and monitor air quality in real time, following standards already implemented in Northern Europe.
The sector also highlights the creation of direct employment during the construction and operation of the plants, as well as the mobilization of investments , many backed by European funds such as Next Generation.
The European vision: biogas as a strategic resource
At European level, platforms such as European Biogas Association (EBA) and the European Composting Network claim that the biogas and biowaste treatment be formally recognized as strategic axes in the next EU Bioeconomy Strategy.
The goal is to accelerate waste collection and processing to reduce landfills, increase renewable energy production, and create more sustainable fertilizers.
Among its proposals, the following stand out:
- Promote the separate collection of biowaste and its priority use for biogas and organic fertilizer production.
- Facilitate access to the market biomethane and organic fertilizers.
- Mobilize more European investments for biogas infrastructures.
- Eliminate regulatory barriers and promote the exchange of good practices between countries.
Figures from the Spanish Biogas Association show that, although Spain has great potential, there are currently only 12 biogas production plants, far fewer than the more than 250 in Germany. It is estimated that the widespread development of these facilities could help cover up to 10% of the national gas demand and avoid the use of much more polluting fossil fuels.
The debate surrounding biogas highlights the need to find a balance between energy, environmental, and social objectives . While these plants can offer solutions for waste management and the ecological transition, the projects require greater transparency, local consensus, and adaptation to the characteristics of each region so that sustainability is perceived not just as a slogan, but as a shared reality.
