Renewables Fiasco: Doldrums And Clouds Bring Green Electricity Production To A Halt

  • Date: 25/12/13
  • Daniel Wetzel, Die Welt

Germany’s wind and solar power production came to an almost complete standstill in early December. More than 23,000 wind turbines stood still. One million photovoltaic systems stopped work nearly completely. For a whole week coal, nuclear and gas power plants had to generate an estimated 95 percent of Germany’s electricity supply.

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<u>Ökostrom meldet sich ab </u><br>Wind und Sonne tragen zuweilen über weite Zeiträume fast nichts zur Stromversorgung bei. Als der Orkan „Xaver“ abgezogen war, setze eine Flaute mit Hochnebel ein. In der Erzeugungskurve der zweiten Dezemberwoche wird der Windkraft-Anteil zu einer hauchdünnen Linie. Auch die <b>Solaranlagen produzieren nur für zwei oder drei Stunden am Mittag minimale Mengen</b>. Konventionelle Kraftwerke, in der Grafik die große graue Basis, mussten die ganze Woche über die <b>Last der Stromversorgung fast allein tragen</b>. In Zeiten typischer winterlicher Hochdrucklagen kann eine solche Situation auch mal zwei Wochen anhalten. Der Beitrag von Biomasse- und Geothermie-Anlagen ist so gering, dass er in diesem Grafikmaßstab nicht gezeigt werden kann. Die aktuell verfügbaren Pumpspeicher könnten Deutschland vier oder fünf Stunden lang mit Strom versorgen, nicht aber eine ganze Woche.<br /><br />

Over long periods of time wind and solar energy generate almost no power at all. After the storm “Xavier” died down, the doldrums and high fog set in. In the second week of December the generating curve for the share of wind power shows a very thin line. At the same time, solar panels produced minimal amounts of energy and that for just over two to three hours at noon. Conventional power plants (the large gray base in the graph above) had to carry the full load for power supply for almost the entire week. Such winter anticyclones are quite common and can last two weeks at times. The contribution of biomass and geothermal energy plants is so minimal that it can not be shown in this graphic scale. The currently available pumped storage could supply Germany four or five hours with power, but not for a whole week let alone two.

Last spring, Germans enjoyed a series of cheerful messages that warmed the hearts of fans of the green energy revolution. “Wind and solar power production now at record hight’, announced the “International Economic Forum on Renewable Energies” (IWR ) on 19 April. “Green power with 35 gigawatts is now linked to the grid, this corresponds to the output of 26 nuclear power plants.”

And so it continued: The owners of photovoltaic solar power cracked the previous record on 27 July with a feed of 204 gigawatt hours. Some time later, renewable energy was predicted to generate almost the complete power supply in Germany. On 3 October, for the duration of one hour, the operators of wind and solar systems came pretty close: On the day of German unity at 14:00 hours, renewables produced at least 67 percent of Germany’s electricity needs.

In the face of such impressive numbers who would not dream of the omnipotence of renewable energy? Then came the storm “Xaver” in early December which caused “wind power equivalent to the output of 26 medium-sized nuclear power plants,” the Münster IWR announced cheerfully.

What better proof that renewable energy has already made conventional power plants largely redundant?

Even the energy industry claimed only recently that fairly soon Germany would only need “back-up power plants” to help out during the short periods when the wind is not blowing.

The cheering claims of the eco-statisticians, however, have serious consequences. Many Germans now regard the era of green power close to completion, the green energy shift almost at its goal. Who therefore needs coal power plants?

According to a recent survey conducted by the polling institute TNS Emnid a third of Germans believe that current energy production can be generated “immediately without any coal power or it could be abandoned by 2020.” Germans estimate that electricity generated by coal and lignite power plants to be on average just 25 percent. In truth, it is almost twice as high at 44 percent.

Given this lack of knowledge it is hardly surprising if the energy debate is occasionally marked by euphoric exuberance. “Pull the plug on Vattenfall”, “Expropriate RWE”, “Drive E.on out of the country” – why not do so today if renewables generate so much electricity already?

The statistics of the apparently beautiful green electricity production, however, have one catch: They give a completely false sense of security. During the cold winter period renewable energy often fails to generate any appreciable amount of electricity for weeks and months. A foretaste of this problem was presented by the storm “Xavier” in early December: As soon as it was gone, doldrums and high fog arrived.

Wind turbines stand still for days

Last week Germany’s wind and solar power production was consistently near to non-existent. More than 23,000 German wind turbines stood still for days. One million photovoltaic systems, subsidized by consumers to the tune of with 108 billion euros, stopped work nearly complete and delivered a few kilowatt hours only very briefly during lunch. For the whole week unloved coal, nuclear and gas power plants had to generate an estimated 95 percent of Germany’s electricity supply.

For the new Economic and Energy Minister Sigmar Gabriel (Social Democratic Party, SPD) the unreliable contribution of renewable energy presents a dilemma: on the one hand, he may not want to be seen to slow down the green energy transition (Energiewende).

On the other hand, it will not add anything to the German power supply if the green power expansion continues and when in the future 40,000 instead of the current 23,000 wind turbines stand still in the doldrums – or when two million instead of one million solar panels do not generate any electricity during the long winter darkness.

Full story (in German)