Revisiting the debate about the future of Germany’s energy supply

The future scenario in Germany appears obvious: Renewable energies are to be expanded and conventional power stations are to be closed down. Simply add on a few storage systems and power grids and the German energy transition is complete – but is it really that simple?


For decades, the German population has feared nothing more than a nuclear disaster. After the Fukushima accident Chancellor Merkel and her government finally decided to close down all of the remaining nuclear power plants within eleven years. But climatologists have been warning us about climate change since the early 70s. As a result, the government has also been forced to develop a plan designed to help decrease CO2-emissions until 2050. As a consequence of this, and in order to reduce greenhouse gases, Germany has also decided to shut down its fossil fuel power plants.


Germany’s energy mix before Fukushima and now. The red component represents the climate impact of each source. (Based on and VDI 2007)

Germany’s energy mix before Fukushima and now. The red component represents the climate impact of each source. (Based on and VDI 2007)

Now the country has to fight a battle on two fronts. Renewable energies primarily replace another CO2-free one, viz. nuclear, while the use of fossil fuels decreased slightly (see Graphic). This is one of the reasons why it is very probable that the next climate change goal in 2020 will not be met. Additionally, in order to compensate for the remaining nuclear power plants, Germany must theoretically double its wind power capabilities. To achieve these aims, the rate of expansion of renewable energy had to be about one order of magnitude larger (see


Is it possible for Germany to be fully powered by renewable energies by the end of this century? There are a few optimistic, yet non-reviewed studies, like Greenpeace’s “Plan B” or “Kombikraftwerk2” produced by the Agency of Renewable Energies. They predict that it can be achieved by way of relatively small efforts, by installing plants, storage and backup systems. Anyhow, most of these studies have critical issues: they ignore, for example, changing weather conditions or assume an unrealistic decrease in the amount of energy consumed. I propose to consider the calculations made by Fritz Wagner, retired German plasma physicist and former director at the IPP. He has generated simulations for a fully renewable supply that also takes into consideration sector-coupling or an international power grid. Even in the best case scenario it is more likely that Germany will need to multiply the level of power generated from renewable sources by ten or twenty times the current rate. Wagner also warns about the underestimation of dimensions of storage systems and their operational limitations.


The famous banner of the anti-nuclear movement at a protest-camp against coal mining near Cologne, Germany in 2017. Is it in times of climate change still legitimate to reject nuclear fission and fusion?

The famous banner of the anti-nuclear movement at a protest-camp against coal mining near Cologne, Germany in 2017. Is it in times of climate change still legitimate to reject nuclear fission and fusion?

About 71 % of Germany’s population (according to an Emnid study from 2017) agrees that climate change is one of the biggest threats to today’s society. But in 2016, 70 % of Germans also wanted to avoid nuclear fission according to a study from YouGov. Fusion seems fascinating but does not play a major role: for example, when Wendelstein 7-X created its first hydrogen plasma in 2016, fusion was a trending topic in the German news for about a week. However, in the government’s declaration on the energy policy, fusion is not even mentioned.
So, nuclear power of any kind appears to remain something of a hot potato in this country. In most cases, it is only associated with potential risks and nuclear leftovers. The contradiction between phasing out nuclear power and attaining climate goals is often downplayed by politicians, independently of their party membership (see both the government‘s declarations and the party programmes of CDU, SPD, Alliance 90/The Greens, The Left). Meanwhile, the European Union is keeping its nose out of this struggle. The Parliament in Brussels has declared that each country is free to choose the method of supply it prefers, just as long as the EU member states accomplish the international climate goals.


Given the problems explained above, I think, we need to embark upon a renewed debate of Germany’s energy future. In an unbiased discussion, we need to figure out an energy mix that will minimise the risks for both humans and the environment. I personally have come to the conclusion that we initially should focus on phasing out the use of fossil fuels for power. Nuclear power will be necessary as long as the problems of pollution are as present as they are today. I know that continuing to use nuclear as a source of power will be a tough decision. The full argumentation would explode beyond the scope of this article. In the long run, nuclear fusion should, together with renewable power, play a crucial role. It may be able to supply the growing energy demand world-wide much more adequately than a complex system based ONLY on renewable sources. Anyway, we must accept that fusion will not help us to reduce the CO2 emissions before 2070 or even later. Though emissions have to be rapidly decreased already in the coming years, if we want to succeed in stopping climate change. Fusion can help in the longer run to meliorate the two major disadvantages of wind energy and Photovoltaics, which is low power density and intermittency.


On the other hand, we might also stick to the current strategy, which means: we continue to hope that sometime within this century renewable energy will be sufficient for our needs. However, if we are to fail, the result would be a simple one: the power supply, even that of 2100 will be a dirty and noxious one, if sufficient at all. That would be putting “Planet Earth last”.

authorbox_Fabian-WieschollekI am a student of Physics and I will be initiating my master’s thesis in fusion research by the end of this year. I intend entering into the theoretical fields, because he mathematical description of nature has always been an interesting challenge. For me, convincing society of visions of a sustainable future is more exciting than maths itself. That’s why I have enjoyed debating this topic even since my days at school.

Fabian Wieschollek (23) from Germany is currently based at: Garching near Munich, Germany, (Picture: private)