*3.2. Economic Evaluations*

Before the considerations of economic evaluations, the current study only considers the configurations which can achieve 100% of renewable fraction. To evaluate the simulation results, the optimal configurations were ranked by two economic outputs, the cost of energy (COE) and the net present cost (NPC). The COE is referred to as "*the average consumed cost in producing 1 kWh from the suggested system*" [27]. Moreover, the NPC is "*the consumed cost in establishing, operating, maintaining, and replacing the components of the suggested system in the project lifetime*" [28,29]. Based on a previous simulation background, the project lifetime was assumed to be 25 years. Other specific economic methods and calculations used in the simulations were employed by the validated examinations introduced by [30].
