There is a strange belief in the new green religion that "renewable" always means "good". It doesn’t. Slave labour is a form of renewable energy but is far from good. Wood is renewable but the burning of trees for firewood is causing environmental calamity in Africa. Solar and wind energy are both excellent for many applications such as solar water-heating, windmills on Karoo farms and the provision of small amounts of electricity in remote households, clinics and schools. But they are bad for generating grid electricity - bad for the environment and bad for the economy.
The Western Cape provides a good demonstration of energy realities. About 30km north of Cape Town is Koeberg Nuclear Power Station; a further 30km north is the Darling Wind Farm. A comparison of the two is instructive.
Koeberg consists of two units of 900MW capacity each. It was built in nine years, which included a long delay for sabotage, and completed in 1985. Its average electricity production is about 12 600 gigawatt hours (GWh) a year.
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The Darling Wind Farm consists of four wind turbines of 1.3MW capacity each. It was built in eight months and completed in 2008. According to its website, it is estimated to produce 8.6GWh a year. Wind farms typically produce less electricity than predicted, but let us accept this figure.
The "load factor" or "capacity factor" of a power plant tells what the plant actually generates compared with its capacity. If it has a capacity to generate 100MW but over a period of time actually produces an average of 70MW, its load factor is 70%.
On these figures, Koeberg has a load factor of 80%. This is not bad but it is by no means the best for nuclear stations. In the US, the load factor for nuclear power is 90%. The Darling Wind Farm has a load factor of 18.9%. This is pretty good for wind. In Germany, Europe’s biggest generator of wind power, the load factor is 17%.
It would require 5860 Darling wind turbines to generate the same amount of electricity as Koeberg. Imagine 5860 of these huge machines, each 81m high, compared with Koeberg’s two reactor buildings, each 57m high. Imagine the thousands of kilometres of transmission lines. Imagine the colossal, wasteful, inefficient use of the earth’s resources (wind requires 10 times more concrete and steel than nuclear per kilowatt hour, or kWh).
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