Carbon Footprint of Wine Production: Decarbonization Pathways Through Renewable Electricity and Heat

Wine production is increasingly scrutinized for its climate impact, with energy use in wineries representing a consistent hotspot of greenhouse gas (GHG) emissions. This study quantifies the energy-related carbon footprint (CF) of wine production and assesses decarbonization pathways through renewable electricity and heat integration. Using primary metered data from two Portuguese wineries with contrasting energy profiles, one electricity-dominated and the other heat-dominated, we modeled renewable substitution scenarios and normalized results per liter and per 0.75 L bottle. In the electricity-dominated winery, baseline CF was 0.202 kg CO2e·L−1 (0.152 kg·bottle−1), with 98% from electricity; full renewable substitution reduced emissions by 88.7%. In the heat-dominated winery, baseline CF reached 0.925 kg CO2e·L−1 (0.693 kg·bottle−1), with 99% from thermal utilities; joint renewable electricity and solar-thermal heat reduced emissions by 92.6%. These findings confirm that the optimal mitigation strategy depends on the dominant energy carrier. The proposed framework demonstrates the technical feasibility of renewable retrofits in small and medium wineries and provides a transparent, reproducible basis for low-carbon transition planning in the wine sector.