“…This payback period is calculated by calculating annualized cost ( AC ) which is composed of four components named as ( C acc ) cost each year to operate, ( C mc ) price every single year to uphold, running electricity price to work ( C ec ) which is zero in our case as we have charged fans with the help of renewable source like as solar panel, and annual salvage value ( S a ) during drying system lifetime [ 40 ]. It is written as …”