# Hybrid Wind-Redox Flow Battery System for Decarbonizing Off-Grid Mining Operations
## 2 System Description  
The Raglan mining site, located in northern Quebec, Canada, operates a localized energy network known as \"Network 25 kV-G,\" which supplies both electricity and heat to the site. This network comprises twenty diesel generators and a wind farm with two operational wind turbines. Among these twenty generators, six EMD models (see Figure 3) are equipped with heat recovery loops, forming a cogeneration system that meets the site's thermal energy demands.  
As part of its decarbonization strategy, the Raglan mining company is committed to reducing diesel consumption, a major contributor to the site's greenhouse gas (GHG) emissions. Given the high wind energy potential in the region, the company plans to expand the existing wind farm by adding additional wind turbines to replace the diesel generators scheduled for decommissioning. However, due to the intermittent nature of wind energy, integrating an energy storage solution is essential to ensure grid stability, reliability, and continuous energy supply. To address these challenges, the company is considering a redox flow battery (RFB) storage system to help mitigate wind energy fluctuations and regulate the 25 kV-G network during peak and low-demand periods.  
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**References** & **Context-Application** & **Storage System** & **Results** \\ \hline [PERSON] et al. [29] & \begin{tabular}{c} To address the intermittency of renewable energy sources \\ To manage fluctuating \\ energy demand \\ \end{tabular} & VRFB system & Exergy efficiency of 78.52\% \\ \hline [PERSON] et al. [30] & \begin{tabular}{c} Powering a hybrid air-source \\ heat pump \\ \end{tabular} & VRFB system & Efficiency of wind turbine integration with VRFB \\ \hline [PERSON] et al. [31] & \begin{tabular}{c} Load frequency control model \\ for a wind power system \\ \end{tabular} & VRFB system & \begin{tabular}{c} Higher performance due to the use of frequency-based \\ VRFB \\ \end{tabular} \\ \hline [PERSON] and [PERSON] [32] & \begin{tabular}{c} Energy storage \\ Clean hydrogen production, \\ integrating VRFBs with catalytic \\ reactors to enhance efficiency \\ \end{tabular} & VRFB system & \begin{tabular}{c} Improving the efficiency of \\ catalytic reactors \\ \end{tabular} \\ \hline [PERSON] et al. [25] & \
\begin{tabular}{c} Performance of a VRFB within a \\ microgrid integrating a biomass \\ gasifier and a solid oxide fuel \\ cell designed for electricity \\ generation in \\ rural environments \\ \end{tabular} & VRFB system &
\begin{tabular}{c} Battery performance is \\ highly dependent on the \\ flow of the electrolyte. \\ An efficiency of 84\% was \\ achieved during peak \\ shaving operations. \\ \end{tabular} \\ \hline \end{tabular}
\end{table}
Table 2: Summary of works applying RFB technology.  
The VRB ENERGY all-vanadium redox flow battery, manufactured by a Vancouver-based Canadian company, has been selected for this application (see Figure 4). This battery technology offers high efficiency, long cycle life, and independent scalability of power and capacity, making it well-suited for large-scale renewable energy storage at the Raglan site.  
The project's first phase focuses on optimizing wind farm production, ensuring a complete transition from diesel generators, meeting electrical and thermal energy demands, and appropriately sizing the redox flow battery required for the site's operations. The  
Figure 4: VRB ENERGY all-vanadium flow battery: battery model VRB-ESS, 1 MW, 500 MWh of energy storage capacity installed or in development [49].  
Figure 3: Scheme of the electrical and heating networks.  
successful implementation of this hybrid wind-storage system plays a critical role in achieving the site's long-term energy transition and sustainability goals.