POWER STATIONS | HYDROPOWER
Hydropower on the Ash River A downstream bird’seye view of the Middle Kruisvallei facility
Middle Kruisvallei abstraction works
The Lower Kruisvallei powerhouse
Completed in March 2021, the construction of the Kruisvallei Hydropower Scheme showcases exceptional innovation as well as multidisciplinar y engineering and construction management teamwork in delivering a worldclass clean energy solution.
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ocated on the Ash River approximately 13 km north-west of Clarens and 17 km south of Bethlehem in the Free State, the scheme consists of two small run-ofriver hydropower plants – Middle and Lower – generating a combined output up to 4 MW, which cost approximately R260 million to construct within a tight 18-month programme. The project formed part of Round 4 of South Africa’s Renewable Energy Independent Power Producer Programme (REIPPP), with the power purchase agreement (PPA) awarded to Zevobuzz (RF) as the IPP. Zevobuzz (RF) is majority owned by Red Rocket, with H1 Holdings as a shareholder. Red Rocket is a pan-African IPP with previous experience in wind and solar projects. This is Red Rocket’s first hydropower investment.
Team dynamics Zevobuzz employed Red Rocket as the EPC
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IMIESA July 2022
PROJECT TEAM Client/Independent Power Producer: Zevobuzz (RF) Civils, Structural & Hydraulic Design Engineers: Zutari EPC Contractor: Red Rocket Civil & Mechanical Contractor: Eigenbau Hydroelectrical Contractor: Scotta SpA Interconnection Contractor: Tractionel Enterprise
(engineering, procurement and construction) contractor, with Eigenbau appointed as the main design and build contractor, and Scotta appointed as the turbine supply contractor (water to wire). Zutari was, in turn, appointed by Eigenbau as the design engineer. Designs were developed in close cooperation with the contractors, with a strong emphasis on constructability. The Zutari team was responsible for the detail design of all civil and structural works. Another team from Zutari formed part of the management and supervision team of Red Rocket during construction. Zutari also undertook all necessary grid code and network compliance studies, and was responsible for witnessing the factory acceptance tests of electromechanical equipment. Zutari also managed the critical commissioning activities for the EPC. The project included the fabrication and installation of large radial gates and large
active spillway gates, as well as automatic trash rack cleaning machines and switchyards, together with the 13 km transmission line and upgrading an existing Eskom substation to enable the power to be exported to the national grid.
Revisiting the original design proposal A design proposal had been undertaken for each site at a feasibility level over 10 years before the project was realised, with Zutari appointed to conduct a more detailed technical feasibility study. The results of that study indicated the preferred option for project implementation required single turbines at each site of approximately 2.25 MW and 1.55 MW housed in power stations constructed along the Ash River. Each of the two standalone, run-of-river systems has an offtake canal tying into the river above the existing Department of Water
