Feb 03, 2012
The CSIR blunders onBack
Aviation|Cape Town|Construction|DURBAN|Gold|Johannesburg|Pretoria|Africa|Generator|Industrial|Projects|System|Turbines|Africa|China|South Africa|United States|Chevon Refinery|Building|Energy|Equipment|Steel|Mossel Bay|Weastern Cape|Environmental|Power|Turbines
© Reuse this
Referring to the Council for Scientific and Industrial Research environmental- impact assessment (EIA) for 70 wind turbines in the Weastern Cape, I wrote: “These turbines have a hub height of approximately 60 m to 100 m, a blade diameter of between 70 m and 112 m . . . [the distance] from the ground to the top of the blade will be between 130 m and 212 m. For the 130 m turbines, each turbine, plus blades, will be taller than all but 15 buildings in the whole of South Africa. The 212 m turbines will only be topped by the Carlton Centre, in Johannesburg, and will be way taller than any building in Cape Town, Pretoria or Durban.”
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- tological heritage, archaeological heritage and economic impact, but nowhere does it discuss the impact of adding generation to the power system, specifically in the case of Mossel Bay (42 MW). This is no mean amount of power. A medium-sized gold mine draws 42 MW. The whole of Mossel Bay draws about 42 MW (if we exclude the refinery). The Chevon refinery, in Cape Town, uses about 20 MW. If this power is to be shipped out, it has to be collected from the turbines and transported through power lines to the power system.
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- ing at an intermittent load, this becomes something of a factor in the effect on the local power system. A problem called ‘VAR imbalance’ occurs and this can lead to voltage flickers on the existing power system.
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.
Edited by: Martin Zhuwakinyu© Reuse this Comment Guidelines (150 word limit)
Other Terry Mackenzie-Hoy News
Recent Research Reports
Defence 2014: A review of South Africa's defence industry (PDF Report)
Creamer Media’s Defence 2014 report examines South Africa’s defence industry, with particular focus on the key participants in the sector, the innovations that have come out of the sector, local and export demand, South Africa’s controversial multibillion-rand...
Road and Rail 2014: A review of South Africa's road and rail infrastructure (PDF report)
Creamer Media’s Road and Rail 2014 report examines South Africa’s road and rail transport system, with particular focus on the size and state of the country’s road and rail network, the funding and maintenance of these respective networks, and the push to move road...
Real Economy Year Book 2014 (PDF Report)
This edition drills down into the performance and outlook for a variety of sectors, including automotive, construction, electricity, transport, steel, water, coal, gold, iron-ore and platinum.
Real Economy Insight: Automotive 2014 (PDF Report)
This four-page brief covers key developments in the automotive industry over the past 12 months, including an overview of South Africa’s automotive market, trade figures, production and the policies influencing the sector.
Real Economy Insight: Construction 2014 (PDF Report)
This five-page brief covers key developments in the construction industry over the past 12 months. It provides an overview of the sector and includes details of employment in the sector, infrastructure and municipal spending, as well as insight into companies’...
Real Economy Insight: Electricity 2014 (PDF Report)
This five-page brief covers key developments in the electricity industry over the past 12 months, including details of State-owned power utility Eskom’s generation activities, funding and tariffs, independent power producers and prospects for the sector.
This Week's Magazine
In the next 20 years, it was expected that, in Africa, more people would live in cities and towns than in rural areas, United Nations Habitat executive director Dr Aisa Kirabo Kacyira said at the Human Settlements Indaba that took place earlier this month in...
Tough-talking Human Settlements Minister Lindiwe Sisulu has committed government to building 1.5-million low-cost houses over the next five years, telling the Human Settlements Indaba in Johannesburg on Wednesday that the State would achieve this target through the...
Over the past 20 years there has been persistent concern about deindustrialisation in South Africa, as well as the fact that locally produced manufactured products have been increasingly displaced by imports.
Financial agreement for Ghanian independent power producer (IPP) Cenpower Generation Company’s $900-million, 350 MW combined-cycle gas-turbine power plant was finalised earlier this month, paving the way for the project’s construction to begin before 2015 in Tema,...
The revenue implications for South Africa of ‘base erosion and profit shifting’ by corporate taxpayers are firmly in the crosshairs of the Davis Tax Committee (DTC) and Judge Dennis Davis hinted last week that recommendations were being considered to “detect and...