The Green Hobby

From Heinz Dähling

Source: [in German; “translate to English” button in the top right]

For millennia, the use of energy sources beyond muscle strength was limited to mechanical energy from flowing air and water and chemical energy from renewable sources. The limitations of these then also limited the human population, which for millennia barely exceeded a billion. In the middle of the 19th century, around 1.5 billion people settled on earth. Only with the utilization of fossil energy sources, with technical progress in the industrialized countries and the associated increase in food production, the world population rose by leaps and bounds, to 2.5 billion by the middle of the 20th century. However, this is still moderate compared to the subsequent tripling to 7.5 billion today,which took place almost exclusively in developing countries. And all forecasts assume that this development will continue. In view of this, going back to mechanical and renewable energy sources and calling it “sustainable” is more than strange.

A few basic numbers for the classification of different types of energy should contribute to the insight that the way back no longer exists. The fundamental knowledge that chemical energy is more efficient than mechanical energy should have become known to mankind at the latest when gunpowder was invented. The mechanical energy to lift 1 kg of weight by one meter is 0.00000272 KWh. One kg of heating oil contains around 10 KWh of heat from combustion and 1 kg of uranium 235 can produce a thermal amount of energy of 2.3 * 10 ^ 7 KWh.

An open-cast lignite mine (Hambach) produces 110,000 tons of coal every day, corresponding to 660,000 MWh. A good third of the calorific value would be converted into electricity if it were converted into electricity. An average 3 MW wind turbine achieves a daily yield of 15 MWh at an optimistic 20% of its nominal output. This means that around 15,000 windmills would be required to do the same thing as opencast mining, half of all wind power plants installed in Germany. The opencast mine defaced a few tens of square kilometers, the windmills the entire republic with steel and concrete that had to be disposed of after a few decades, not to mention the problems of the fluctuating availability of wind energy. The calorific value of the coal mined in the Hambach opencast mine has a share of 0.015% of the fossil fuels mined worldwide. Is it really climate-relevant? Nordstream 2 would bring 55 billion cubic meters of gas into the country annually, with a calorific value of 550 million MWh, more than double that of the open pit, which has an annual output of around 240 million MWh.

Our policy boasts that we already generate more than a third of electricity “regeneratively”. However, electricity has a share of around 20% of Germany’s total primary energy demand. 30% is accounted for by fuels for mobility and 50% for heat generation for heating and industrial process heat. Wind power plants make up roughly a third of the renewable energies, alongside PV and biomass. As a result, wind energy supplies a third of a third of 20%, which is around 2.5% of our primary energy requirement, in view of the enormous expenditure, as good as nothing and, to top it off, this little brings the power grids into serious trouble due to its discontinuity.

If we are to use heat pumps for heating in the future and remain mobile with electric vehicles (it is assumed that we have the same total energy requirement while maintaining our standard of living), electricity generation would have to be quadrupled compared to today. With the shutdown of lignite and nuclear power plants, however, around 40% of electricity generation will initially be lost. In order to guarantee the future additional demand through the addition of wind turbines, their number would have to be increased from 30,000 today to over 800,000. One cannot and would not like to imagine that. The aerodynamically styled blades of the windmills cannot hide the fact that this is a mechanical form of energy generation.

Now the global coal reserves would still last for centuries even with energetic use, with purely material use, as a carbon source for the chemical industry, well over a thousand years. But in the face of the increasing hunger for energy of a galloping global population, one cannot continue to rummage through the globe in search of coal. It is better to preserve the valuable carbon sources, over 90% of which are burned today, for material use. The availability of crude oil, currently the basis of all mobility and therefore essential for the global economy, will, however, exceed its maximum in a few decades according to current knowledge. Switching to other technologies would be urgently required, as new infrastructures cannot be implemented in a few years. The “regrowing” is hardly enough for nutrition globally and cannot make a serious contribution, neither energetically nor materially. As can already be seen from the ranking of the energy densities, the further development of nuclear energy is the only sensible way to secure the energy supply of mankind in the long term without overburdening nature.

Windmills and biofuels are astray, highly subsidized by conventional energy sources (where do concrete and steel come from? Can energy crops be grown without diesel? And what are tractors and harvesters made of? Etc. etc.). The “green hobby” can only be afforded by industrialized countries for a while, but it is not a “sustainable” solution for the rest of the world. At least in this country, politics is exhausted in backward-looking technologies and bans. The fact that one does not really trust the “green turnaround” itself, however, can be seen, for example, in how hard one is trying to complete Nordstream 2.

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