Between 2022 and 2024, a comprehensive study was conducted to connect a photovoltaic power plant combined with a battery energy storage system (BESS) to the existing electrical installation of the Tasiast gold mine, which is powered by Diesel thermal power plants. The aim of this initiative was to enhance the site’s energy autonomy while reducing its carbon footprint.
The study was carried out using a digital network model and covered several essential technical aspects.
First, the existing electrical model was taken over and supplemented by adding the new hybrid power plant.
The power flow study helped validate the sizing of transformers, cables, and high-voltage (HV) switchboards, ensuring that the integration of this plant would not affect the voltage stability of the existing grid.
Next, a short-circuit current analysis, performed according to IEC 60909 standards, was conducted to determine the minimum and maximum currents, ensuring the proper sizing of HV equipment in case of potential failures, and allowing for the development of an appropriate protection plan (selectivity study).
The transient stability study simulated various critical scenarios, such as the loss of the largest generator or the passing of a dense cloud, to verify the system’s stability. The results led to recommendations on configurations to avoid in order to maintain stability, as well as the fault clearing times to be respected.
A harmonic study was also conducted to check the voltage and current distortion rates, ensuring compliance with the limits set by current standards.
Finally, the Arc Flash study, compliant with IEEE 1584 and NFPA 70E 2024 standards, calculated incident energies and defined risk zones. This work led to the selection of personal protective equipment (PPE) and the implementation of necessary Arc Flash labels for operator safety.
This study validated the entire design of the hybrid power plant while ensuring optimal integration with the existing electrical installation of the mine. The hybrid power plant was commissioned in 2024, marking a significant step in the site’s energy transition.
