Project Overview
- Location: Harare, Zimbabwe
- Application: Supermarket Energy Storage
- System Type: Solar-Storage-Diesel Microgrid
- Solution: PCS + DC/DC + STS
- Configuration: 2 Integrated Energy Storage Cabinets in Parallel + Solar PV + 500kW Diesel Generator
Project Background
Located in Harare, Zimbabwe, the SPAR supermarket faces frequent regional load shedding and unreliable grid power, affecting essential loads such as refrigeration, lighting, checkout equipment, and food preparation.
To improve power supply reliability, the project integrates solar PV, battery storage, the utility grid, and a diesel generator into an on-grid/off-grid microgrid, helping maintain critical operations while improving solar energy utilization.
Enjoypowers Solution
Enjoypowers provided a power conversion and switching solution integrating PCS, DC/DC, and STS technologies.
Two integrated energy storage cabinets operate in parallel, each equipped with:
- 1 × 500kW STS for grid-connected/off-grid switching
- 2 × 105kW PCS for bidirectional battery power conversion
- 2 × 50kW DC/DC converters for solar PV power conversion
The system also includes a solar PV generation system and a shared 500kW diesel generator for backup power.
System Operating Modes
Daytime: Solar PV supplies supermarket loads first, with surplus energy charging the batteries. Once the batteries reach the configured charging limit, excess electricity can be exported or sold where permitted. During grid outages, the system transitions to off-grid operation according to its control strategy.
Nighttime: Battery storage supplies essential loads, including refrigeration, lighting, and security systems. When the battery SOC falls below the configured threshold, the diesel generator starts to supplement power and recharge the batteries where supported.
Cloudy Weather or Extended Outages: When solar generation is insufficient and the grid is unavailable, battery storage supplies designated loads. The diesel generator starts when the battery SOC reaches the configured low threshold, helping maintain power availability for critical supermarket operations.
Key Project Benefits
1. Reliable Backup Power
STS supports switching between grid-connected and off-grid operation, helping reduce the impact of power interruptions on critical supermarket loads.
2. Improved Solar Utilization
Coordinated solar PV, battery storage, grid power, and diesel generation help prioritize on-site consumption. Surplus electricity can be sold externally where permitted, adding potential economic value.
3. Flexible Parallel Cabinet Configuration
Two integrated energy storage cabinets operate in parallel, supporting flexible system operation. With appropriate fault isolation and control design, the configuration can improve operational resilience.
Project Summary
The Zimbabwe SPAR supermarket project demonstrates how an integrated solar-storage-diesel microgrid can improve power reliability in areas with unstable grid supply. By integrating Enjoypowers PCS, DC/DC, and STS technologies, the solution supports flexible on-grid/off-grid operation, backup power for critical loads, and improved solar energy utilization.
