Design and Development of a Solar-Powered Rotary Drum Composter for Managing Food-Waste at the University Food Center

The annual value of food waste generated worldwide already reached a staggering $1 trillion. This amounts to 1.3 – 1.4 billion tonnes or one third of food produced for human consumption that goes to waste each year. The Food Center at Don Honorio Ventura State University faces a similar issue a weekly production of 21.5kg of food waste. To address this increasingly concerning issue, a solar-powered rotary drum composter driven by a DC motor was developed. This composter, designed to accommodate up to 20kg of food waste. Analysis of the composter's motor performance reveals significant relationships between voltage, current, speed, torque, efficiency and load. The voltage exhibits an inverse proportional relationship with load, steadily decreasing from 24.8V to 23.3V as the load increases, while the current shows a direct proportional relationship, consistently rising from 4.1A to 9.84A with increased load. Further examination of torque and speed in relation to load indicates a direct and inverse proportional relationship, respectively. Torque increases from 6.68Nm to 27.23Nm with increasing load, meanwhile, speed decreased from 72.74rpm to 55.16rpm. As for the efficiency, it was found out that the composter operates most efficiently when the drum is loaded 12kg, beyond which efficiency gradually declines with increasing load up to 20kg. This decline signifies the diminishing returns associated with higher loads, highlighting the importance of load optimization for sustained efficiency in composter operation.