Food-Embedded Cold Energy Flows in Decentralised Solar Cold Chains

Abstract

Reliable cold storage is needed to reduce meat loss in informal food systems, but conventional cold-chain expansion is difficult where electricity supply is weak and battery-based solar refrigeration is costly. This study develops an hourly techno-economic optimisation framework for decentralised solar-powered cold storage in interconnected open-air meat markets. Using five meat markets in Abuja, Nigeria, the model combines field-derived cooling demand, solar photovoltaic generation, refrigeration, battery storage, phase change material thermal storage, and directed inter-market meat flows. A key feature is that pre-chilled meat is represented as a carrier of product-embodied cooling credit, while phase change material storage remains a stationary cold-side storage component at each market. This allows cooling supplied at one market to reduce the sensible cooling load required at another market. Results show that shifting part of the storage function from battery storage to phase change material thermal storage reduces battery capacity by approximately 67\% and lowers total system cost by up to 15\% compared with battery-only systems. Allowing inter-market cooling-credit exchange further reduces total system cost by 8\% and aggregate phase change material storage capacity by 35\%, mainly by reallocating refrigeration and storage requirements across connected markets. The findings show that product flows can change where cooling services are required, allowing refrigeration and storage capacity to be coordinated across connected sites. Accounting for the product-mediated redistribution of cooling demand extends decentralised energy-system planning beyond isolated demand nodes and may inform cluster-level cooling infrastructure design in other infrastructure-constrained food networks.