It is regarded as heresy, only to be whispered furtively in dark corners, to say there are significant problems with wind generators. When they are raised, they tend to be brushed aside by governments that enjoy spending taxpayers’ money on subsidising their construction, and, naturally by those who benefit from their sale and construction.
So fixed has the idea of alternate “clean” energy become that half-page ads are placed in newspapers to brag about it. Those who believe wind generators are not saving the planet spark outrage.
But doubts about wind turbines do not always come from people determined to rape the planet, decimate wildlife and pollute the air. Doubters are often engineers tasked with dealing with wind-generated power. Indeed, some engineers of the Green persuasion accept the problems and apply their minds to solving the drawbacks. ***
Since our government is determined to continue building wind turbines, talking loftily of the need for an “energy mix”, it is worth looking at how wind generators fare in Germany – it being the country that has adopted the Green mantra so completely that it has shut down half its nuclear power stations.
One large grid-management company, E.ON Netz, is responsible for about a third of Germany’s electrical capacity. It has made a closely argued and coolly technical critique of wind power. E.ON Netz must manage and meld into the grid almost 50 percent of Germany’s total wind generation capacity. In doing so, it confronts significant operational and technical difficulties.
The company says* since it is difficult accurately to predict when wind-generated power will be available, wind generators need their own transmission lines. Not only is this an additional cost, the irregularity of wind power means traditional power stations (Germany still has coal-fuelled ones) must be run in tandem with wind generators so demand peaks can be met. Logic says the more wind generators are used to generate electricity, the more conventional power stations must be available.
Wind generator output is not only irregular, says E.ON Netz, but it can and does drop to zero. Even during times of peak demand, and when all generators are working at their maximum, their average contribution to the grid is a low 8 percent and can drop even lower. The company reported that during cold winter and hot summer periods, wind-power plants make a minor contribution towards covering consumption exactly when demand is high for heating and cooling power.
Surely more wind generators would solve this problem, one would think. It might, but with a catch as two other German studies of wind generation point out.
Another study** says that as wind power capacity rises, the lower availability of wind farms determines the reliability of the whole grid. For example, special measures must be in place to deal with faults in the grid when wind power plants disconnect themselves even in the event of minor and brief voltage dips.
The above are the views of German electrical engineers tasked with managing the electricity grid. Some of the difficulties with wind power are known to moderate Greens*** with engineering backgrounds, so it is possible that these known drawbacks will disappear. However, the question of cost, particularly to the taxpayer and consumers, remains an issue.
There are other drawbacks felt particularly by those who live near wind generators, but the main problems of wind generators are not the subjective views of individuals or groups. They concern their technology, hidden subsidisation from the public purse, engineering, cost and erratic electricity output.
If one puts aside theories of global warming caused by emissions of carbon dioxide, and fears of even modern nuclear power stations, two key questions remain: “Why build wind generators at all and, how long will they last?”
If German engineers are struggling with integrating them into the national grid, we are unlikely to be better at it, if Eskom’s record is to be the judge.
* E.ON Netz Wind Report 2004/5; **Dena study
*** Renewable & Sustainable Energy Reviews
Keith Bryer is a retired communications consultant.