ECO-FRESH Nigeria: Integrating Circular Bioenergy, Solar Cold Chains, and Agroecology for Methane Mitigation and Food Security.

ECO-FRESH Nigeria is an integrated circular food-system model linking organic waste–to
bioenergy (anaerobic digestion), solar-assisted cold storage, and agroecological production 
support to address methane mitigation and food security simultaneously. We evaluated ECO
FRESH using a mixed-methods, quasi-experimental design across three pilot hubs with matched 
comparison communities and baseline endline measurement over 12 months. Operational 
monitoring tracked waste diversion, biogas production, and cold-room reliability, while impact 
evaluation assessed postharvest losses, quality outcomes, farmgate prices, and incomes. Methane 
mitigation was quantified using a measurement, reporting, and verification (MRV) framework 
with sensitivity analysis. Average organic waste diverted was 5.1 t/day and biogas production 410 
m³/day. Cold-room throughput averaged 6.8 t/day with 95.2% uptime and 92.3% temperature 
compliance. Difference-in-differences estimates show postharvest losses declined by 12.0 
percentage points (95% CI: -14.3 to -9.7), accompanied by higher Grade A share and lower 
rejection rates (p < .001). Farmgate prices increased by ₦40/kg, and monthly net farm income 
rose by ₦20,700 (≈24% growth). MRV results estimate an annualized net climate benefit of 
18,540 tCO₂e/year (range: 14,200–23,900). Impacts were broadly inclusive, though smaller for 
producers farthest from hubs, highlighting logistics as a key equity constraint.