3.4.1. −25% Overnight Fuel Cost

At a 25% decrease of the overnight diesel and coal price, the Li-ion BESS installation sizes sharply decreased, as shown by Figure 15. The bimodal distribution that was once present in MED and MVC systems in Camasusu have become a tight distribution, suggesting that RE-favored generation is no longer feasible. Systems on Lubang Island also favored diesel. Figure 16 also shows that all systems exhibit uncertainty in optimum storage sizes. Generation costs have decreased (Figure 17), especially for MVC, which consumes large quantities of diesel due to its high electrical energy intensity. Bimodal spreads of LCOE and LCOW have disappeared due to systems heavily favoring diesel over RE.

**Figure 15.** Distribution of optimum sizes of energy components on Camasusu Island (**top**) and Lubang Island (**bottom**) at −25% overnight fuel price.

**Figure 16.** Distribution of optimum sizes of water storage and desalination unit on Camasusu Island (**top**) and Lubang Island (**bottom**) at −25% overnight fuel price. There is high uncertainty in the optimum water storage sizes in all systems on both islands.
