The energy transition has placed biogas in the spotlight as a solution for utilizing organic waste and generating renewable energy. However, its deployment in Spain is not without controversy. While government bodies are promoting this technology with subsidies and ambitious plans, several municipalities are openly rejecting the projects due to potential environmental and health risks . The tension between the need to decarbonize and environmental protection has become a constant.
The most recent example is the experimental plant inaugurated by IRTA in Constantà (Tarragona), presented as a landmark for being the first managed by a public research institute. However, in places like Alloza, Calamocha, Badajoz, and Arenas de Cabrales, neighborhood associations have managed to halt or challenge the projects . This dichotomy reflects a fundamental debate: where and how should these facilities be located?
The institutional commitment to biogas
The IRTA Mas Bové center in Constantà has ​​launched a facility that converts pig slurry and poultry manure from its own farm into biogas, fertilizer, and reclaimed water. This project, which cost over €660.000, generates 96.697 cubic meters of biogas annually, equivalent to the energy consumption of 165 homes . It also produces 1.262 tons of fertilizer and 3.816 cubic meters of water for irrigation. The facility is designed for the agri-food sector to conduct pilot tests and validate new technologies, such as biomethane production.
This initiative is part of the Catalan government's strategy, which approved a plan in 2024 to deploy biogas in Catalonia. The goal is to reach an annual production of 2 TWh by 2030, representing 8% of the region's gas consumption . To this end, €46 million in subsidies were allocated in 2024, with an additional €25 million earmarked for this year's call for proposals. The government argues that the controlled digestion of livestock manure reduces greenhouse gas (GHG) emissions and prevents soil and groundwater contamination.
Neighborhood opposition in several communities
In contrast to this institutional view, neighborhood associations in Teruel, Badajoz, and Asturias have spoken out against projects they consider invasive and dangerous . In Alloza, the plan envisions treating 150.000 tons of agricultural and livestock waste annually, but residents fear the plant will end up receiving waste from other regions if there isn't enough local raw material. Furthermore, the area is designated as vulnerable to nitrate pollution, so a massive application of digestate could compromise aquifers and the ecological status of crops.
In Calamocha and Fuentes Claras, the Stop Biogas Jiloca platform denounces that the facilities would be located less than one kilometer from the town centers, violating the recommended distances in other regions such as Castilla-La Mancha, where 4.000 meters are required. They also warn of the concentration of plants in the same area and the lack of public participation. In Badajoz, those affected by the growing opposition to the biogas plants planned for the Rocilla estate point out that the nearest homes are only 1.800 meters away and that waste trucks would increase traffic and the risk of accidents.
A debate on regulation and the future
The opponents' arguments focus not on rejecting the technology itself, but on the lack of specific land-use planning. They are demanding clear rules regarding minimum distances, limits on plant concentration, odor controls, and digestate management . In Arenas de Cabrales, the local association asserts that the biogas plant would be located 190 meters from a campsite and near the Cares River, within the Natura 2000 network. The City Council and the Regional Government of Asturias support the project, but residents have collected more than 12.000 signatures against it.
IRTA insists that experimentation is necessary to improve the process and reduce impacts. The Mas Bové plant will serve as a full-scale laboratory to test emerging technologies and train technicians. However, local residents' associations point out that there are already documented cases of plants with foul odors in Aragon, such as in Loporzano, Tierz, and Quicena. They demand that planning precede investment, not the other way around.
The future of biogas in Spain will depend on finding a balance between the need to utilize waste and the protection of rural areas. While government agencies see this technology as an opportunity to reduce emissions and create jobs, local residents are demanding greater transparency and genuine participation. The Catalan example demonstrates that research can progress, but without common regulations, conflict will persist in many regions.
