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Upper Blink Water, Eastern Cape


Region: Eastern Cape
Installed By: Kestrel
Purpose: The village of Upper Blink Water is made up of 350 Rural houses, that did not have access to any form of electricity before the installation of a solar Mini-Grid system 3 years ago. Kestrel was selected for the wind Turbine addition.

The Mini-Grid system had a diesel generator as backup, but the use of diesel increased the cost of Electricity to R7,50/kW.h

The solar system was installed at the start of the project 3 years ago. After a refining process and system integration proposals, Kestrel was selected for the wind Turbine addition. Installation began at the end of 2021 and was completed in mid-2022.

The system is a combination of 6 x 3500-watt wind turbines that are connected to a 3-phase 380Vdc system generated by the SMA inverters. We at Kestrel have used the ABB solar inverter for each of our wind turbines. The output of the wind turbines to the grid is controlled 2 ways.
Firstly we use a smart relay, that uses pre-set parameters of:

1 – if solar supply is more than 42kW.h, do not allow wind to supply
2 – if solar is less than 42kW.h but less than 35kW.h allow 2 turbines to supply
3 – if solar is less than 35kW.h but more than 28kW.h allow 4 turbines to supply
4 – if solar is less than 28kW.h allows all 6 turbines to supply

All this is dependent on the wind blowing.

Then as an additional safety feature, there is also frequency control. As soon as the battery bank (150kWh) nears full. The Solar inverter will increase the AC output frequency above 50hz.

This increase in frequency will then limit the output of the ABB wind turbine inverters and thereby control the balancing of the system.

After the completion of the installation, connection and commissioning of the system, it was handed over to the local municipal department

Below can be seen the amount of power that was supplied to the grid during an average day

Below can be seen the amount of power that was supplied to the grid during the start of the month of Dec 2022.12.09
To date the system has been able to supply 1,12MW.h of energy