Hartenbos Waste Water Treatment Works Solar PV Plant and Microgrid

Details

Hartenbos Waste Water Treatment Works Solar PV Plant and Microgrid

Solareff, in partnership with Element Consulting Engineers and the Mossel Bay Municipality, delivered a groundbreaking hybrid solar PV and microgrid system for the Hartenbos Waste Water Treatment Works. Under normal conditions, it operates in parallel with the Eskom grid. In the event of grid interruptions, the Battery Energy Storage System (BESS) takes over, supported by solar generation during daylight hours. Standby diesel generators provide additional backup if needed. Excess solar energy is fed into the municipal grid, reducing long-term energy costs and boosting sustainability for the Mossel Bay area.

This award-winning project enhances energy resilience for critical municipal infrastructure while supporting South Africa’s clean energy goals.

Project Highlights:

Site Size: 3.5 hectares of municipal land

Location: Hartenbos, Western Cape

System Type: Hybrid grid-tied microgrid with solar PV, battery storage, and diesel backup

Solar Generation Capacity: 2.112MVA from 4,536 PV Panels

Battery Storage: 4,586kWh

BESS Inverter Station Capacity: 2.75MVA

Generator Farm Capacity: 1.6MVA

Substation: Includes 11kV switchgear and advanced control systems that switch seamlessly between solar, battery, and diesel backup.

A standout feature of the Hartenbos Waste Water Treatment Works Solar PV Plant and Microgrid is its advanced Power Plant Controller (PPC), a first-of-its-kind solution developed by Solareff for the South African market. Acting as the intelligence behind the microgrid, the PPC seamlessly manages the interaction between the solar PV plant, battery energy storage system, grid supply, and diesel backup generators. Through real-time monitoring and automated control, the PPC optimises energy use, maximises renewable energy generation, and ensures uninterrupted operations during grid disturbances and outages. This innovative technology sets a new benchmark for municipal energy infrastructure, demonstrating how intelligent energy management can improve resilience, reliability, and sustainability for critical public services.

Click here to watch our project video of this award-wining solution.

Award Recognition

Solareff is proud to have been recognised for excellence in the South African solar industry, receiving the Solar EPC of the Year award at the prestigious SAPVIA Industry Awards Ceremony held on 2 July 2026. Presented by the South African Photovoltaic Industry Association (SAPVIA), the award recognises Engineering, Procurement and Construction (EPC) companies that demonstrate exceptional performance in the successful delivery of solar photovoltaic projects. This achievement was awarded in recognition of Solareff’s delivery of the Hartenbos Waste Water Treatment Works Solar PV Plant and Microgrid, a landmark municipal energy project that exemplifies innovation, technical excellence, and sustainable infrastructure development.

Further reinforcing the project’s impact, the Hartenbos Solar PV Plant and Microgrid was named Top Performing Project at the AMEU Awards 2025. Presented by the Association of Municipal Electricity Utilities (AMEU), these awards celebrate excellence and innovation across South Africa’s municipal electricity sector. The Hartenbos project was recognised for its outstanding contribution to energy resilience, environmental sustainability, and operational excellence in municipal services. As one of South Africa’s leading municipal renewable energy initiatives, the project has set a benchmark for sustainable infrastructure development, demonstrating how innovative energy solutions can strengthen critical public services while supporting the country’s transition to a cleaner energy future.