Windturbines: the whole truth.
I1. The energy source.
The source of energy from where a windturbine is impelled is the so-called "kinetic energy" of the wind, therefore that of moving air. Of course this applies also to windmills of hundreds of years ago and to the most modern windturbines 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 windturbines 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 is a calculating factor which allows to take into account, among others, 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 most strongly as a result of the variable windspeed and the factor v3 between a maximum value and zero or almost zero. That cube is the death blow for reliable electricity production by windturbines.
It is impossible for a wind turbine to produce current of a useful strength 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, windturbines 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 windturbines. 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 necesary with 600 MW during weeks or even months. Every big 3 MW windturbine can perhaps produce with an avarage power of 0.75 MW - 1.1 MW depending how the wind blows.
All the exposed aspects completely determine the behaviour of windturbines. This is impossible to change in any way. Also not by any so-called "innovation", no matter what the stakeholders and promoters of windturbines claim to the contrary. A law of nature will remain in force for ever, no matter whether one considers windturbines 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 ocurring variations in that small impelled power are totally dependant on the random windspeed. The average impelled power of a wind turbine will therefore be considerably smaller per year 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 windturbines 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 windturbines in Germany. The windturbines are spread from the North Sea coast to Switzerland/Austria. This proves that the spreading of windturbines over great distances does not help making the total power more constant, no matter whether dealing with on- or offshore windturbines. According to the ordinary common sense: the sum of completely unpredictable, "chaotic" quantities can of course be no different than just as completely unpredictable and chaotic. No matter whether the groups of windturbines are on land or sea. No matter what wind energy propagandists claim. It also becomes clear how difficult it will be to extract a steady total input power for the grid from this chaos of hundreds of very sharp peaks in the wind power by adjusting the power of the conventional powerplants.
This totally unpredictable behaviour of windturbines and groups of windturbines 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!
These is also the percentages counted on by the E.ON technicians in Germany. When examining with certain detail the second graphic it becomes clear that the conclusion drawn by these technicians is not at all unlogical.
This means that about 90% of the total so-called installed wind power must be kept available or even provided for at the conventional power plants, in order to be able to compensate for the variations of wind power. On top of that it will be necessary to install many very costly and complicated technical adjustments of the national grid. Such as new high voltage power lines, switch yards, protection equipment etc.
All this is the reason why promoters of wind energy will never publicize such a graphic of the hundreds of variations of the aggregate wind power of a great number of wind turbines . They speak not a word about the very real risks that these variations incur for the reliable operation of the national grid. Sometimes they tell only that the power of a wind turbines 'varies with the force of the wind. But that is of course only a small part of the whole and unpleasant story and therefore misleading.
You'll read a lot more about all the disadvantages and the inherent risks of wind energy in logic succession in the following chapters. As in the chapters IV1 and VI1 .
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