The North wind doth blow,
And we shall have snow,
And what will the robin do then, poor thing?
That old nursery rhyme, though, nowadays seems somewhat out of date.
Perhaps, a more relevant refrain would be;
The north wind doth blow,
And the turbines will go
And generate more power.
In 2011, South Africa introduced the Renewable Energy Independent Power Producers Procurement Programme which included an initiative to install 17.8GW of renewable energy in South Africa before 2030. Shortly afterwards, wind farms and solar farms started being built in South Africa.
Wind farms consist of turbines mounted on top of tall towers to allow the turbine blades to be rotated by passing wind. The first wind farms built in South Africa used steel towers.
In other parts of the world, though, towers for wind farms are sometimes made from precast concrete as well as from steel. In 2013 Concrete Units teamed up with Windtechnic, a Spanish Company, who design and build concrete towers in Europe and South America.
GOUDA WIND FARM
In 2014, Windtechnic and Concrete Units were awarded a contract to manufacture 46 concrete wind towers for Acciona Windpower to use in a wind farm being built in Gouda which is near Tulbagh in the Western Cape.
The towers for the Gouda wind farm are 100m high and the turbine on top of each tower can generate 3 MW. The farm can, thus, feed up to 138 MW into the national grid. Each tower is made up of 17 precast concrete segments which are 20 metres long. The widest segment is 6 metres wide and the heaviest segment weighs 65 tons. The 782 segments required for the contract were cast by Concrete Units in their Cape Town precast yard and were transported, by truck, to the Gouda wind farm.
Gouda was the first wind farm in Africa where the towers were made from concrete rather than steel.
ROGGEVELD WIND FARM
In 2019, Concrete Units and Windtechnic were awarded a contract to supply 47 towers to Nordex Energy South Africa. The towers are used in a wind farm built at Roggeveld which is situated between Matjiestontein in the Western Cape and Sutherland in the Northern Cape.
The Roggeveld wind farm consists of 47 towers which are similar to the towers for the Gouda wind farm. The 799 tower segments required for the farm were, as before, cast by Concrete Units in their yard in Cape Town and trucked to the wind farm.
The award of contracts for the construction of wind farms forming part of round 5 of the South African REIPPP is scheduled for 2022, and Concrete Units expects to be involved in building more towers for the wind farms.