# Hybrid Wind-Redox Flow Battery System for Decarbonizing Off-Grid Mining Operations
## 6 Results and Discussion
### Model Results
#### 6.2.1 General Trend Results
In addition to the analysis of the number of installed wind turbines, we explore the variation in the previous parameters with the wind penetration rate related to both installed capacity and the specific site operating conditions:  
\[Wind\ Penetration(\%)=WP(\%)=\frac{E_{wind}}{E_{load}}\times 100 \tag{3}\]  
As such, in Figure 15, we account for the actual wind energy contribution over a year, not just the installed capacity. Although the overall trends in Figure 15 resemble those in Figure 14, key distinctions emerge in subfigures (b) and (c):  
Figure 15: Performance indicator variation with the wind power penetration rate (WPP, %) for a system with 120 MWh battery and two generators running continuously: (**a**) LCOE vs. WPP; (**b**) LCOS vs. WPP; (**c**) diesel savings vs. WPP; (**d**) energy discharged from batteries vs. WPP. (a) The Levelized Cost of Energy (LCOE) steadily decreases as wind penetration increases from 10% to 50%, reaching a minimum of approximately CAD 490/MWh at 50%. Beyond this point, the LCOE rises, indicating an optimal penetration level of around 50%. (b) The Levelized Cost of Storage (LCOS) experiences a sharp decline between 10% and 20% wind penetration, after which the reduction becomes more gradual. LCOS reaches zero at 50% penetration, confirming this as the most economically efficient point for storage operation. (c) Diesel consumption shows an almost linear decrease throughout the entire range of wind penetration, reinforcing a strong negative correlation between wind contribution and fossil fuel reliance. (d) Battery discharge increases with wind penetration, peaking around 55% and then slightly decreasing. This suggests a saturation point in the contribution of storage to system balancing. Together, these results confirm that a wind penetration rate of around 50% offers the best trade-off between cost reduction, storage utilization, and diesel offset in this configuration. Impact of the Number of Operating Generators and Additional Wind Turbines on the Diesel Savings  
For a system with a 120 MWh battery, Figure 16 illustrates the impact of wind turbine additions on diesel savings under different generator operation scenarios (0 to 3 generators running). The most significant diesel reduction occurs when no generators operate permanently, resulting in over 150% savings compared to the baseline. The >100% diesel savings reflect not only avoided electricity production from diesel but also the replacement of diesel used for thermal needs (e.g., building or process heating) through excess wind energy and heat recovery. This indicates net-negative diesel consumption relative to the baseline for electricity generation only when combined power and heat offset benefits are considered. Figure 16: Share of diesel saved for different numbers of continuously running generators, depending on the number of wind turbines, with 160 MWh redox battery storage. The relative diesel savings decrease as more generators remain permanently online (Figure 16b-d). This demonstrates that continuously operating diesel generation limits the economic and environmental benefits of wind integration.