# 2.5 MW Off-Grid Solar-Storage Microgrid for Overseas Mine Twenty 125 kW PCS units in parallel deliver 2.5 MW for a large overseas mine, coordinated by a PCC controller with diesel backup for high-reliability off-grid power. Serving a large overseas mine, this project uses twenty 125 kW PCS units in parallel to build a 2.5 MW microgrid. A single PCC controller coordinates the system, driving contactors to switch between grid-tied and off-grid modes while integrating diesel generators as backup power to keep critical mine loads running. Project Background Large mines are often far from the grid and need stable megawatt-level power for crushers, mills and dewatering pumps. Traditional diesel-only solutions have huge fuel consumption, while PV-only solutions cannot guarantee night-time or cloudy-day supply. The customer wanted a PV+storage+diesel grid-forming microgrid to replace the traditional approach with clean, stable and scalable off-grid power. System Configuration 20 × 125 kW PCS units (2.5 MW parallel output) 1 × PCC power coordination controller Diesel generators as backup AC source Contactors + grid-tied/off-grid transfer switches Project Solution System topology: 20 PCS units form the grid in parallel. The PCC controller dispatches PCS between grid-tied and off-grid modes based on grid/diesel availability; PCS runs grid-tied when diesel is online and forms the off-grid grid when diesel is offline. 整套系统采用中腾数能构网型 PCS 与 MPPT 直流耦合技术，具备毫秒级并离网切换、一簇一管理、SOC 主动均衡与高防护等级等能力，可根据现场条件灵活扩展功率与容量。 Site Photos Site photos: mine electrical building and outdoor containerized storage/PCS installation. Operation Results Twenty PCS units output 2.5 MW to meet high-power mine loads PCS runs grid-tied when diesel is online and auto-switches to grid-forming off-grid when diesel stops PCC unifies switchover and power sharing with <20 ms transfer Any single device failure or withdrawal does not affect overall system operation Get a similar solution If you have a similar microgrid or energy storage project, contact VGRID for a tailored solution and quote. [More cases](/en/cases)