• Delphi study of biomethane market development in Ireland’s dairy sector. • Market design lens identifies barriers and enablers for circular bioeconomy adoption. • Financial, political and supply chain risks constrain biomethane scaling. • Digestate valorisation is key to nutrient recycling and biomethane strategy success. • Holistic approach needed to align energy, agricultural and environmental goals. Biomethane is emerging as a promising renewable energy source (RES) for reducing agricultural greenhouse gas (GHG) emissions, improving nutrient management and strengthening energy security. When integrated into biorefinery systems, it can transform agricultural residues into renewable bioenergy and organic fertilisers, supporting circularity and sustainable development. However, uncertainties remain regarding how this transition technology will be governed and its real capacity to deliver lasting environmental benefits. Ireland’s high-GHG-emitting agriculture and intensive dairy sector create a favourable context for biomethane development, yet progress remains uneven under existing energy policies. At the same time, a government-led biomethane strategy offers opportunities for systemic transition. This study examines the enabling conditions for circular bioeconomy (CBE) development in this context, focusing on how nutrient supply into anaerobic digesters and demand for renewable energy and bio-based fertilisers can be supported through well-functioning marketplaces. Using a modified Delphi method and structured risk classification, expert stakeholders from Ireland’s dairy sector assessed future development pathways. The study highlights significant obstacles, including poor utilisation of digestate, lack of supply chain coordination, regulatory inconsistencies and financing difficulties. Biomethane is often seen only as a bioenergy source, but in order to truly contribute to sustainable development, it must be recognised as a multifunctional lever, capable of connecting agriculture, energy, society and the environment.
Corrigan et al. (Fri,) studied this question.