Performance Analysis of High-Efficiency Motor and Variable Speed Drive in Black Tea Processing Machinery

Purpose: The present old standard efficiency motors (SEM) in black tea processing machinery consume large amount of electricity, thus increases the cost of production. Technologically improved high-efficiency motors (HEM) or HEM coupled with variable speed drive (VSD) could be useful to achieve high-energy efficiency. Therefore, a study was conducted with the focus to determine the feasibility of introducing HEM and VSD in withering and rolling machinery of black tea manufacturing. Methods: A withering trough and two different capacity rotorvane rollers were selected for the study, and the energy consumption of different treatments was measured, and specific energy consumption, annual bill savings, simple payback period, and potential carbon dioxide emission reduction were calculated. Results: The results showed that introducing HEM or HEM coupled with VSD saves the energy compared to SEM (p < 0.05). The corresponding potential annual bill savings was estimated as Sri Lankan Rupee (SLR) 13,219 to 66,096, carbon dioxide emission reduction was 467 to 2336 kg CO2 per year, and payback period was 0.06 to 0.11 years for a factory handling 8000 kg green leaves a day. Conclusions: This study found that replacing existing SEM with HEM or HEM with VSD is economically viable. © 2020, The Korean Society for Agricultural Machinery.