The Gouda Wind Farm: April 2015

A new wind farm has been taking shape at Gouda in the Drakenstein Municipality of the Western Cape.

When Lynnette and I recently went to Porterville for the stargazing event at the Porterville Golfclub, organized by Nathalie Wagenstroom from the Porterville Tourism Office, I hadn’t been out that way for quite some time. I was therefore surprised to find that a new wind farm had sprouted up to the right of the R44 just past where it crosses the railway line.

This wind farm will consist of forty-six 100 m towers each carrying a 3 MW Acciona wind-power turbine so that the site can produce 138 MW at full capacity. The construction started in 2013 and was scheduled for completion in 2014 with the power being delivered to a 132 kV distribution network at the Windmeul substation near Wellington. Go here to read more about the project in the August edition of Engineering News. You will find a comprehensive overview of the project as summarized in the August 2013 NERSA public hearings. There is more information here on the webpage of Energy4Africa. Driving past there it was clear that they are way behind schedule.

Top left: View of the wind-farm from the R44 before reaching the turnoff to Gouda and Porterville. Top right: View of the wind-farm from the R44 just after turning off to Gouda and Porterville. Bottom left: The R44 passes right next to these enormous. structures. Bottom right: The wind-farm from the top of the bridge that takes the R44 over the railway line.
Top left: View of the wind-farm from the R44 before reaching the turnoff to Gouda and Porterville.
Top right: View of the wind-farm from the R44 just after turning off to Gouda and Porterville.
Bottom left: The R44 passes right next to these enormous. structures.
Bottom right: The wind-farm from the top of the bridge that takes the R44 over the railway line.

The Gouda Wind Facility is the first wind farm in South Africa to use concrete towers. Steel towers are imported while concrete towers can be manufactured locally. Another advantage is that one can build taller towers, up to 120 m, at a reduced energy cost. The wind farm at Hopefield consists of thirty-seven, 95 m steel towers each carrying a 1.78 MW turbine from the Danish firm Vestas. The installation will produce 66 MW at full capacity. Go here to read about the installation in the May 2014 edition of Engineering News.

Hopefield wind powered generators on our way home
Hopefield wind powered generators.

The Gouda installation was erected by Acciona Energy and Aveng while Sarens supplied the equipment to transport and lift the various sections of the towers as well as the turbine blades and the turbines. At full capacity Gouda will supply enough power for 146 000 low income homes or 60 000 medium income homes.

Top left: Acciona's 3 MW turbines are as large as a medium sized caravan and perch on top of a 100 m concrete column. Top right: The parked vehicles give one an idea of the size of these structures. Bottom left: Another attempt at giving you an idea of the size of those columns. Bottom right: The previous photo enlarged and, in case you missed him there is a person wearing a yellow construction vest in the structure next to the tower.
Top left: Acciona’s 3 MW turbines are as large as a medium sized caravan and perch on top of a 100 m concrete column.
Top right: The parked vehicles give one an idea of the size of these structures.
Bottom left: Another attempt at giving you an idea of the size of those columns.
Bottom right: The previous photo enlarged and, in case you missed him there is a person wearing a yellow construction vest in the structure next to the tower.

Each blade of the three-blade turbine is 50 m long and the pitch of the blades is increased as wind speed drops to increase the torque and maintain the rotation speed. If the wind speed increases the pitch will be decreased to reduce the torque. At wind speeds of around 20 m/s at the hub height (that is around 70 km/h) the turbines are shut down. In rural areas the turbine blades are required to generate no more than 35 decibels of sound which is classified as less noise than a normal conversation.

When one sees these turbine blades rotating they always look as if they are in slow motion. A bit of mathematics reveals that if the rotor is turning at 10 revolutions per minute the tips of those 50 m long blades are travelling at over 180 km/h. Low flying birds cannot judge the speed of those rotor tips correctly and, because the rotors taper, the tips are far less visible than the sections closer to the hub, so they fly into them, with fatal results. This is especially the case for large, slow birds like geese, pelicans, cranes and storks. Raptors tend to be watching for prey on the ground so they also often fall foul of the blades. From an environmental perspective, it is important that wind farms should not be built on the migration routes of these birds, or in areas where they congregate to feed or breed.

Butterfly World

When one drives along the R44 from Stellenbosch toward Wellington one passes Butterfly World on the right about 300 metres after the intersection of the R44 with the R101 at Klapmuts. If you are coming directly from Cape Town on the N1 get off at exit 47 and turn right onto the R44.  Butterfly World is the second exit on you left.

From the outside the appearance is not really impressive but don’t let that fool you. Behind that rather ordinary facade is a very interesting establishment that presents one with a lot more than just pretty butterflies.

Butterfly World also doubles as a rescue and rehabilitation centre for birds, several types of reptiles, small mammals, arachnids and a variety of tropical fish.   There is an enormous amount to see at Butterfly World so please don’t rush it.  Take your time go through really slowly and look under every leaf and behind every bush, because there are lots of surprises waiting to be discovered.

Butterfly World also has a very reasonable restaurant and for the younger visitors there is an activity centre as well.

I hope this collection of photographs will entice you to drive out there and pay them a visit.

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