Wind turbines: the whole truth.
I1. The energy source.
The source of energy for a windturbine is the so-called "kinetic energy" of the wind; that is the energy in moving air. Of course this applies both to windmills of hundreds of years ago and to the most modern Wind turbines of today.
This kinetic energy can be expressed by a single physical formula. Without exception, all characteristics, and consequently the yields, the risks and the costs of Wind turbines, are outcomes of that sole physical formula. It is that formula which determines the quantity of the impelling kinetic energy.
The formula is: Es = f . mspec . v3
In this formula is:
- Es is the kinetic energy per second supplied by the moving air.
- f a calculating factor which takes into account, among other things, the diametre of the rotation circle of the tip of the propeller blades.
- mspec the specific mass of the impelling air.
- v3 the cube of the windspeed.
The specific mass of air mspec, which expresses the mass per cubic metre, is exceptionally small: no more than 1.18 kg/m3. Compared with the specific mass of water, which is 1,000 kg/m3, air is 900 times lighter.
According to technical concepts and compared with other driving media applied to other power tools, the speed of wind is also extremely small.
Therefore, the power of a wind turbine varies between a maximum value and zero, or almost zero, according to the variable windspeed and the factor v3. That cube is the death blow for reliable electricity production by Wind turbines.
It is impossible for a wind turbine to produce a useful output at a windspeed of Beaufort 2 or 3, given the minimal kinetic energy of the wind in those conditions. To state the opposite is a propagandistic fairy tale, for any model wind turbine, big or small, with a horizontal or a vertical shaft. With such little wind, Wind turbines simply stand still. As you will often see.
Just to compare: consider the behaviour of a steam- or waterturbine:
In the case of a steamturbine, steam under very high pressure and temperature rages through the turbine at hundreds of kilometres per hour. Also in a water turbine, an enormous mass of water of thousands of kilo's storms through the turbine. It is not surprising, therefore, that the power of steam- and waterturbines is easily hundreds of times higher than that of Wind turbines. One should realize: A conventional fuel burning powerplant or a hydroplant can easily produce electricity with near to 100% reliability, and as the plant operator deems necessary, with 600 MW during weeks or even months. Every 3 MW windturbine will, over a period of a year, perhaps produce energy that is equal to an average power of 0.75 MW - 1.1 MW, depending how the wind blows.
The variables outlined above completely determine the behaviour of Wind turbines. This is impossible to change in any way. Not by any so-called "innovation", no matter what the stakeholders and promoters of Wind turbines claim to the contrary. A law of nature will remain in force for ever, no matter whether one considers Wind turbines useful or senseless. This proves that the kinetic energy of the wind, which must provide the mechanical power to move the propeller has, inevitably, three nasty characteristics:
- As we just stated, the power can only be extremely small in comparison to any other power generator as for example a steam- or waterturbine.
- As a consequence of the uncontrollable variation of the windspeed, the power is bound to vary extremely strongly and frequently between the maximum and zero.
- Those extreme and frequently occurring variations are totally dependent on the random windspeed. The average power per year of a wind turbine will therefore be considerably smaller than the maximum power it was built for. Nothing can ever be done about this.
These two graphics show to what extent the power of Wind turbines varies:
This first graphic shows the power of a 600 KW wind turbine straight on the Dutch North Sea coast, during a whole year (8,760 hours). As was to be expected, these variations were considerably stronger still than the windspeed variations, due to that cube in the formula. The following graphic was taken from the German E.On Windreport 2005.
This graphic shows the overall power of 7000 Wind turbines in Germany. The Wind turbines are spread from the North Sea coast to Switzerland/Austria. This proves that the spreading of Wind turbines over great distances has little effect on making the total power more constant, no matter whether dealing with on- or offshore Wind turbines. According to ordinary common sense, the sum of completely unpredictable, "chaotic" quantities remains completely unpredictable and chaotic. No matter whether the groups of Wind turbines are on land or sea. No matter what wind energy propagandists claim. It also becomes clear how difficult it will be to maintain a steady power for the grid by adjusting the power of the conventional powerplants to counteract this chaos of hundreds of very sharp peaks in the wind power.
This totally unpredictable behaviour of Wind turbines and groups of Wind turbines has a particularly unpleasant consequence, namely that from the total of the installed windmill power no more than 10%, or even less, can be counted on as a truly reliable substitute for conventionally produced electricity!
This is the percentage counted on by the E.ON technicians in Germany. When examining in detail the second graphic, it becomes clear that the conclusion drawn by these technicians is not at all illogical.
This is a specially unfavourable fact, always ignored by the stakeholders of Wind turbines. Maybe because they do not fully understand this phenomenon? Or is it that they deliberately keep silent about it because this fact is so very unfavourable for reliable electricity production?
It indeed means that around 90% of the total so-called installed wind power (turbine capacity) must be available from conventional power plants, in order to compensate for the variations of wind power.
This is obviously one of the main reasons why wind energy is not only not useful but even extremely hazardous, if introduced, with no restrictions, as a substitute of conventional and thus reliable production of electricity. The variation in the total power output from wind turbines is uncontrollable. See also chapters 4 and 6.
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