A compact, off-grid pasteurizer that uses solar energy to heat milk to safe temperatures. The system brings milk to the pasteurization setpoint and holds it precisely (e.g., 63 °C for 30 min – LTLT or 72 °C for 15 s – HTST), using a stirrer and PID control for uniform heating. An automatic timer, buzzer, and optional cooling help finish the batch cleanly. Built with food-grade stainless steel, it reduces spoilage and improves shelf life for small dairies and village collection centers—without relying on grid electricity or fuel.

Parts Used:

1. Solar PV Panel + MPPT Charge Controller – harvests/optimizes solar power
2. Battery (LiFePO₄ / Lead-acid, 12–24 V) – stores energy to run the heater & controls
3. Heating Element (DC immersion or AC via inverter/SSR) – transfers heat to milk
4. Food-Grade SS304 Vessel (with lid & drain valve) – pasteurization chamber
5. Temperature Sensor (PT100/DS18B20 + signal module) – accurate temperature feedback
6. Microcontroller (Arduino/ESP32) with PID – controls heating, timers, safety logic
7. Solid-State Relay/MOSFET – switches the heater safely
8. Stirrer (SS shaft + DC motor) – uniform temperature, prevents scorching
9. Insulation (PUF/Rockwool) & Gaskets – reduces heat loss, improves efficiency
10. Safety Components – thermal cutoff/thermostat, fuse, E-stop, pressure relief
11. Optional Add-Ons – solar thermal jacket (ETC/flat-plate), cooling coil/plate heat exchanger, LCD/OLED display, SD card/data logger, IoT/GSM alerts, CIP spray ball