The selection of an appropriate dispatch strategy is considered as a major concern when designing hybrid energy system (HES) since it has large effects on the stability, reliability, environmental and economic performance of the system. The cycle charging (CC) strategy is a default dispatch strategy in HOMER software. However, the main drawback of this strategy is that it uses the resource and load data in the current time step and has no information about the future. This paper aims to investigate the optimum design of an off-grid PV/diesel/battery HES for electrifying a rural area in Iraq. A new dispatch strategy which has 12-hour foresight for the load and solar production is developed using MATLAB Link module in HOMER software. A comparison between the proposed strategy and default cycle charging (CC) strategy in HOMER is carried out by considering the technical, economic, and environmental performance. The results show that the proposed strategy achieves better performance than CC strategy by having NPC of $4.03M, renewable fraction of 41.3% and CO2 emissions of 851377 kg/year. For the CC strategy, these values are calculated as $4.19M, 33.9% and 957477 kg, respectively. The sensitivity analysis is also performed to reduce the effect of input parameters on the optimization results and determine the critical parameters. The research findings can play a crucial role in the development of more effective energy management systems.