The South African Cape is famous for its 18 official wine routes and two brandy routes, which are amongst the most scenic in the world, featuring many historic wine estates that date back centuries. You can take your time exploring this magnificent part of South Africa's Western Cape Province and enjoy sampling its splendid wines and brandies. But in terms of a sustainable future, the area has much more to offer.

 

The wind park covers yearly 200,000 South African homes

Although still dependent on fossil fuels, South Africa has been unobtrusively creating one of the world’s most progressive alternative energy plans,
quietly building up wind power capacity. Installed by Spanish company Acciona, Gouda was the first wind farm in South Africa and is now one of
the largest in the whole country. It started feeding the grid in 2015 and has
463 MW unit capacity turbines mounted on concrete towers with a hub height of 100 m. Located in Drakenstein, 100 km northwest of Cape Town, the wind park can produce enough power every year to cover the demand from around 200,000 South African homes. This corresponds to an estimated annual production of 423 GWh. What is more, 406,000 t of CO2 emissions from coal-fired power stations are avoided each year.

 

Locally produced concrete instead of imported steel

The wind farm was the first to use locally produced concrete instead of the usual imported steel towers. Vast quantities of Sika products were supplied for
construction of these 100 m tall towers. Jacques Reinecke, Head of Renewable
Energy at Sika South Africa, spearheaded the specification and installation and
provided on-site training.

 

Each tower consists in four precast concrete columns of 20 m in height

The Sika products used in large quantities for the construction of the towers included Sikadur-31 CF (1 t per tower), Sealing Backing Cord (22 km) and SikaGrout-295 ZA (30 t per tower). Each column consists of four precast segments that were sealed and grouted together on site. Due to their extreme height, each tower is comprised of four precast concrete columns of 20 m in height, joined on site, one on top of the other. A final segment carrying the nacelle brings the 46 towers to a height of 100 m each. 

 

Back-up support material for surface seals on precast concrete components

Horizontal joints on the tower segments were sealed with Sika EVA Backing Strip. This semi-rigid, closed cell cross-linked construction foam is designed as a tough, flexible and resilient back-up support material for surface seals in load-bearing joints. It can also be used as a bedding seal under precast concrete panels and to prevent loss of grout when joining precast concrete components.

 

Adhesives and repair mortars for high initial and ultimate mechanical strength

Once joined together, the vertical and horizontal joints of the precast segments
were sealed with Sikadur-31 CF and Sikadur-31 DW. Both products are moisture-tolerant, thixotropic, structural two-part adhesives and repair mortars based on a
combination of epoxy resins and special fillers. They provide high initial and
ultimate mechanical strength and are impermeable to liquids and water vapor.
Sealing Backing Cord was placed into the expansion joints to regulate the depth
of seal and to provide a solid backing onto which the sealants were placed.

 

Sika-trained local labour

Using local Sika-trained labor, DD Materials completed the grouting of all vertical cavities applying SikaGrout-295 ZA (a one-component, ultra-high-strength, cement-based grout specifically designed for use in the renewable energy field) under metal bases, between concrete segments and to fill cracks, gaps and large voids. The product was sent for fatigue testing and is now certified for durability. The workers were also trained in concrete repair, waterproofing and epoxy applications. The entire project was instrumental in creating an average of 400 jobs, with hikes of up to 800 employees during the construction phase.

 

High content of local products

One of the client’s primary requirements was a high content of local products.
100% of all Sika products used in the Gouda Wind Farm project were locally
produced. Tried and tested for their reliability and endurance, the products employed in this project add to the sustainability value of Gouda Wind Farm.

 

All requirements were surpassed

All PPE requirements were adhered to on site on a daily basis and each employee underwent induction before commencing work. Acciona has a well-established and certified corporate Integrated Management System (IMS) incorporating quality (ISO 9001), environment (ISO 14001) and health & safety (OHSAS 18001). As a final accolade, the Gouda Wind Farm project won the coveted Fulton Award for Innovation in Concrete. Since the emphasis for this huge project was to use local content and local labor, it surpassed all expectations, proving local really is best.

 

South Africa`s ambitious Integrated Resource Plan

South Africa is meeting the ambitious target of 10,000 GWh of renewable energy under its Integrated Resource Plan, an energy blueprint for the period from 2010 to 2030. The country’s wind power is now about 40% cheaper than new coal power produced by the national utility. The successful growth in procured capacity from 10 MW to 3.3 GW in just four years was not driven solely by the imperative to address climate change. The rapid uptake and scaling up of the government’s renewables ambitions were due to the simple fact that wind has become a no-brainer. A wind power farm can be set up four times faster than a new coal plant and conceivably six times faster than a nuclear station. It is far cheaper and infinitely safer than both. It is modular and can better use existing grid capacity. Moreover, it is all realized with private money and does not require the government to lay out billions for a new build program. The wind
industry has matured and reached a stage where its business case speaks for
itself. Wind power has come of age.

 

For more information about energy practitioner Brenda Martin in the CEO Blog, published by the South African Wind Energy Association, visit: SAWEA 

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