Environmental Life Cycle Assessment of a Hybrid Solar–Biomass Micro-CHP System for Livestock Decarbonization in European Agricultural Settings

The intensive livestock sector’s reliance on fossil fuels for space heating (SH) necessitates sustainable alternatives to reduce agricultural greenhouse gas (GHG) emissions. This study conducts a cradle-to-grave Life Cycle Assessment (LCA) to evaluate a Partially Evaporating Organic Rankine Cycle (PEORC) micro-combined heat and power (micro-CHP) system for swine nursery facilities. A solar–biomass hybrid (PS1) and a standalone biomass-driven architecture (PS2) are compared against conventional diesel (REF1) and biomass (REF2) boilers across Greece, Denmark, and Poland. Across the three locations, PS1 reduced Climate Change impacts by 89.6–108.3% relative to REF1 and 23.2–161.1% relative to REF2, while PS2 achieved reductions of 93.0–112.3% and 48.2–190.7%, respectively; reductions greater than 100% reflect net-negative modeled impacts driven by grid electricity displacement under the substitution assumptions. PS2 was environmentally superior in most impact categories across all locations. Omitting the solar field avoided substantial embodied burdens in resource depletion and ecotoxicity and reduced Climate Change impacts by up to 116.0% relative to PS1. Transitioning from conventional R134a to the low-GWP (Global Warming Potential) working fluid (WF) R1233zd(E) substantially mitigated severe Climate Change and Ozone Depletion Potential (ODP) risks associated with simulated operational leakages, reducing the WF’s Single Environmental Score (SES) by approximately 90%. Despite the eroding effect in substitution credits caused by the dynamic grid decarbonization at EU level, bio-mass-driven micro-CHP systems present a highly effective decentralized de-carbonization strategy for agricultural heating.