The CSIR blunders on
By: Terry Mackenzie-
Published: 03 Feb 12
In last week’s instalment of this column, I made a mistake.
Referring to the Council for Scientific and Industrial Research environmental-
This is not correct. It should read: “. . . [the distance] from the ground to the top of the blade will be between 95 m and 156 m. For the 95 m turbines, each turbine, plus blades, will be taller than all but 35 buildings in the whole of South Africa. The 156 m turbines will only be topped by the Carlton Centre and Ponte, in Johannesburg, and will be way taller than any building in Cape Town, Pretoria or Durban.”
The EIA discusses visual impact, impact on bats, impact on birds, noise impact, paleon-
So, apart from the forest of 42 wind turbines, there will be a whole lot of power lines, a fact which the EIA does not mention. Then again, if you have a 42 MW generator operat-
There is also another phenomenon called ‘voltage slide’, which causes the system voltage to collapse slowly. Now many people I have spoken to about this topic just brush it aside with comments like: “There are wind turbines all over the world and this doesn’t happen.” All over the world, right, but not where the main source of generation is 500 km away. It is a real consideration. But, hello! Ignored in the EIA.
Other matters left out are the effect on radar equipment in the area (both civil and military) and the general effect on aviation. Stringing a whole lot of 156 m structures around the place just has to affect flying patterns. Also not addressed is whether a wind turbine ever produces the amount of energy used to construct it. In other words, if X kWh is used in construction, does the turbine ever produce more than X kWh? It is hard to get the figures accurate but it takes about 40 GJ to produce a ton of steel from ore and 25 GJ if it is produced from scrap steel.
A big wind turbine (Vesta 152) weighs 267 t, so, if it is all steel (which it is not), it must produce at least 4 200 000 000 000 kJ over its life time. If it is a 2 500 kW turbine, then, over 2 000 windy hours in a year, it will produce 180 000 000 000 kJ. Thus, many years will pass before it actually produces more power than it generates. And, on a production basis, a wind turbine has negative energy consumption. So, why, oh, why, are these projects going ahead? Or even being contemplated?
There is a reason for this, but it is often screened behind the emotion of global warming and saving the planet. The reason is allowing the US and China to continue polluting unabated. Watch this space and more next week.