Environmental and techno-economic analysis of a biomethane energy community in southern Spain

P. Gómez-Sánchez de Rojas, J. Victoria Rodríguez, C. Morales-Polo, M.M. Cledera-Castro

Sustainable Energy Technologies and Assessments Vol. 82, pp. 104496

Resumen:

The increasing focus on renewable energy has spotlighted bioenergy from waste materials, emphasizing waste-based biorefinery processes for waste management and renewable energy production. Anaerobic co-digestion has emerged as a viable alternative, producing higher energy–density biogas. This study conducts a comparative environmental life cycle analysis of current waste management practices, fertilizer consumption, and domestic heat consumption with the incorporation of a biomethane plant in a small municipality in South-Spain. It evaluates the combination of more than two substrates while conducting a comprehensive analysis of the full range of available waste to optimize biomethane production and minimize the carbon footprint.

Additionally, a novel business model is introduced, involving energy communities comprising municipal stakeholders, small businesses, and households engaged in gas self-consumption. This model aims to benefit the municipality economically and environmentally, ensuring local energy supply security and potentially offering affordable renewable fuel prices through European funding subsidies. Currently, while gas-based community energy models exist, the injection of biomethane into the grid for community consumption is yet to be realized. However, the European Union’s goals of promoting a circular economy and empowering rural sectors indicate progress towards this objective. From 2027, a new EU Emissions Trading System 2 scheme will impose emissions payments on buildings and small industries, highlighting the need for cost-effective decarbonization strategies where biomethane could play a crucial role.

The environmental impact assessment reveals that implementing a biomethane injection system significantly mitigates all environmental impact categories. A well-balanced co-digestion mixture enhances biomethane production and emission abatement, achieving an 89% reduction in CO₂-eq emissions in domestic heating. Establishing a cooperative model with municipal collaboration proves viable, with a 17% internal rate of return and a possibility to decrease the price paid by the energy community below 40€/MWh. Potential revenue from biogenic CO₂-eq, compost, and gas sales through Guarantees of Origin and Proof of Sustainability further enhances profitability, underscoring the environmental and economic potential of anaerobic co-digestion within energy communities.

Palabras Clave: Anaerobic co-digestion; Biomethane energy community; Environmental life cycle assessment; Cost-benefit analysis; Rural decarbonization

Índice de impacto JCR-JIF y cuartil WoS: 7,400 - Q2 (2025)

Referencia DOI: https://doi.org/10.1016/j.seta.2025.104496

Publicado en papel: Octubre 2025.

Publicado on-line: Agosto 2025.

Cita:
P. Gómez-Sánchez de Rojas, J. Victoria Rodríguez, C. Morales-Polo, M.M. Cledera-Castro, "Environmental and techno-economic analysis of a biomethane energy community in southern Spain", Sustainable Energy Technologies and Assessments, Vol. 82, pp. 104496, Octubre 2025. [Online: Agosto 2025] doi: 10.1016/j.seta.2025.104496