The Stortemelk hydropower project is the implementation of one of the three projects included in the Botterkloof and Merino II feasibility study by Aurecon for Stortemelk Hydro (Pty) Ltd, with NuPlanet as the project developers.
The project consists of a single 4.4 MW vertical Kaplan turbine installed at the Botterkloof Dam on the Ash River near Clarens, in the Free State Province of South Africa.
The power station had to be constructed between two existing dams without affecting their operations and stability. This required deep excavations through the Botterkloof Dam embankment in between the Botterkloof Dam and Boston A Dam spillways.
Aurecon was appointed as the EPCM Contractor by Stortemelk Hydro (Pty) Ltd, A SPV owned by the Renewable Holdings (Pty) Ltd who are also the owner of the existing Bethlehem Hydro power stations. As EPCM Contractor, Aurecon was responsible the entire detailed design, construction supervision, ECO monitoring, contract administration and programming, as well as the Health & Safety oversight.
Through Aurecon’s multidisciplinary capability, we were able to provide all necessary services in house for our client, which helped to convince stakeholders that the EPCM approach, rather than the typical EPC approach, was the most appropriate solution without increasing the overall project risks. This is the first time an EPCM contractual structure has been used under the South African REIPPP programme.
Aurecon packaged services in a cost effective manner to NuPlanet Hydro and implemented innovative solutions in the design to maintain the construction value within budget. Based on our experience with small hydropower stations, Aurecon offered a compact solution comprising of single vertical double regulated Kaplan turbine (Saxo type) with the short penstock route optimised to avoid endangering the existing structures.
NuPlanet, with the assistance of the Aurecon team, managed to obtain all necessary approvals to reach financial close to allow construction to proceed.
Construction commenced in September 2014.
NuPlanet managing director Anton-Louis Olivier said: “This project was made possible by the ongoing relationship between ourselves and Aurecon. The Aurecon team understands the context of small hydro and private project development which allows for clear management of the complex and highly regulated development process as well as efficient risk allocation during development and construction.”
The successful implementation of the project will contribute to the energy on the South African power grid from a renewable resource whilst also greatly contributing to the local economy of Dithlabeng Municipality in terms of both employment of locals and local procurement.