Battery-Free Solar Refrigeration for Off-Grid Clinics and Homes: A Direct-Drive Design with Ice-Bank Thermal Storage

A first-principles design and computation study (SIMULATED, NOT MEASURED; no device built or hardware-tested) of a battery-free solar refrigerator that stores cold instead of electricity: a 600 Wp photovoltaic array wired directly to a 120 W variable-speed DC compressor freezing a 55.2 kg ice bank. For a 200-litre cabinet at 5 C in a 32 C ambient the daily cooling load is 1,209.4 Wh thermal; the ice bank gives three days of autonomy with no useful solar input; equivalent full-power compressor run time is 5.79 h per day at a design COP of 1.74; a fully melted bank refreezes in about two sunny days. Ten-year cost is estimated at USD 2,120 against USD 6,950 for a battery-based equivalent (saving USD 4,830). Vaccine storage in the 2-8 C band is addressed explicitly: the ice bank at 0 C is physically separated from the vaccine chamber, with a controlled cold path, a 2.5-7.5 C control band, and independent temperature logging and freeze indication. Includes the computation script and its saved outputs.