By Liesl Frankson

Hydropower developer NuPlanet has begun construction of the 4.5 MW Stortemelk hydropower plant near Clarens, in South Africa, after recently reaching financial close for the development.

The project is expected to take around two years with completion scheduled for mid-2016. The company was awarded preferred bidder status under the South African Government’s Renewable Energy Independent Power Producer (REIPP) programme.

The REIPP programme, which was launched in 2011, was designed to procure 3 725 MW of energy, from renewable energy sources. In the two years following the launch an additional 3 508 MW was added to the original amount and this continues to grow. This has opened up the market for more contracts such as the Stortemelk hydropower plant, which means more companies, can produce power independently and feed South Africa’s grid.

Doing things differently

The Stortemelk hydropower deal comprises of a ‘split contract’ structure with an engineering, procurement and construction management (EPCM) arrangement rather than the EPC structure that is more commonly used in the REIPP programme.

Having been involved in the project since the feasibility stage Aurecon, an engineering, management and specialist technical services company, was appointed to provide the EPCM services for the implementation of the project.

Bertrand Rochecouste Collet, Aurecon project director, says they were are able to provide all of the necessary services in house to NuPlanet, 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.

“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,” adds Anton-Louis Olivier managing director of NuPlanet.

Work and outputs

The power station has to be constructed between two existing dams without affecting their operations and stability. The construction will require deep excavations through the Botterkloof Dam embankment in between the Botterkloof Dam and Boston A Dam spillways.

A single vertical Kaplan turbine will be installed at the Botterkloof Dam on the Ash River and Aurecon offered a compact solution for the turbine, optimising the short penstock route, to avoid endangering the existing structures.

The plant is expected to produce 25 GWh per annum and reduce Carbon dioxide by 25 000 ton every year.

The project will contribute to Dithlabeng (Bethlehem and Clarens) Municipality’s economy through local employment and procurement.