By Prof. Fritz Vahrenholt, Die kalte Sonne
Not going to work, says German energy expert Prof. Fritz Vahrenholt
(German text translated/edited/subheadings by P. Gosselin)
The goals of the German transition to green energies are simple in terms of energy policy:
1. phase-out nuclear energy by 2022,
2. phase-out coal by 2035,
3. phase-out oil and gas in parallel and completely by 2050.
The energy needed for electricity, heat, mobility and industrial processes in climate-neutral Germany will then have to be supplied by wind and solar energy and a few percent by hydropower and biomass. This is at least according to the plans of the German government, which are supported by all major social players.
Is this realistic?
Today, wind and photovoltaics supply slightly less than 30% of the 600 terawatt hours of electricity (1 terawatt hour Twh is 1 billion kilowatt hours Kwh). Today 126 Twh is supplied by wind energy and 46 Twh by photovoltaics. For 600 TWh, the same mix would need 439 Twh of wind and 161 Twh of solar. For the sake of simplicity, let us assume that this amount of electricity should be generated by the largest wind turbines, namely 5 megawatt turbines positioned 1000 m apart. With an annual efficiency of 25%, a turbine produces an average of 5 MW x 0.25 x 8760 (hours) = 10,950 Mwh = 0.01095 Twh. For 439 Twh we would need 40,000 such turbines. To accomplish this, an area of 200 km x 200 km (40,000 sq km) would be required.
Too much unneeded surplus power
But we still would not reach the goal. Wind energy is produced when the wind blows, and not necessarily when the consumer needs it. With a power supply in Germany based solely on volatile sources, 36% of the electricity generated annually can be consumed directly (source: Dr. Ahlborn). The rest is surplus electricity that has to be stored. For economic reasons, storage in hydrogen alone is the best option here. For this purpose, a gigantic number of electrolysis plants would have to be installed.
Huge area required for electricity from wind turbines
However, it is completely uneconomical to dimension the capacity according to the extreme peaks of strong wind events. Therefore, about 12% of the wind energy has to be regulated. This now leaves 52% of the electricity generated that can be stored in hydrogen. Electrolysis of hydrogen, storage/methanization and conversion back into electricity leaves only 15.6% of the 52%. The entire conversion chain generates a loss of 2/3 of the electricity used. 36% plus 15.6% result in about 50% of the generated wind power being usable. Thus, we need twice as many turbines. The area for the 80,000 wind turbines becomes 80,000 km², which corresponds to an area of 283 km x 283 km (80,089 sq. km).
Now add the demand from transport and heating…
But we remain very far from the finish line. Up to now we have only covered the electricity demand with 2 x 439 Twh, but without supplying the demand from transport and heating. Also with demand from transport (today 600 Twh) and heat (today 1200 Twh) we have storage and conversion losses when the necessary electricity is generated by wind and solar. Here we only consider wind for this, because with photovoltaics, the annual efficiency of 10% full load hours is significantly lower and the land consumption is many times higher. This makes our calculation extremely conservative.
Devastating lack of efficiency
Assuming that the transport sector can actually be powered by battery vehicles, which is justifiably doubtful, converting cargo transport, maritime transport or air cargo transport over to electricity is already adventurous. Instead, synthetic fuels would have to be used.
And here as well the electricity calculation is devastating. As Dr. Detlef Ahlborn was able to show, the Frankfurt airport alone consumes 14.7 million liters of kerosene per day (before Corona), which comes out 4.3 million tons annually. 4.3 million tons of kerosene correspond to an energy value of 47 Twh. If one wanted to synthesize kerosene from electricity with the help of hydrogen (assumed efficiency 50%), 100 Twh of electricity would be needed. Just for the Frankfurt airport alone, this comes out to being as much as the German wind energy industry currently produces (126 Twh).
Minimum 900 Twh for heating and transport
Next we conservatively assume that all passenger transport also can be powered with electricity and that only a quarter of the amount of the 600 Twh of energy consumed today (since electric cars are more efficient by this factor) is needed. However, we also want to drive a car when there is no wind, and as explained above, most of this electricity has to be put through the chain of hydrogen, storage, and re-electrification, thus doubling the input electricity to 300 Twh.
We further assume that the current demand of 1200 Twh for heating can be reduced to a quarter through electrification (heat pump) so that here too, due to the necessary intermediate storage of wind power via hydrogen, the necessary doubling of wind energy leads to 600 Twh. If synthetic gas from wind power, hydrogen, is used directly, the yield is even worse because the efficiency of the heat pump is not applicable. Transport and heat therefore in the best case lead to a wind power demand of 900 Twh. This results in an area requirement of another 80,000 km², thus we are up to 160,000 km² of area needed by wind turbines (approx. half the area of Germany).
Another 600 Twh for heavy industry
But we still haven’t reached the ultimate target because the most difficult part is still unsolved. Emissions from the steel, chemical and cement industries (10% of CO2 emissions) require 600 Twh, according to industry estimates (www.in4climate.nrw). This is easy to understand if one remembers the above example of Frankfurt Airport. And plastics, pharmaceuticals, insulating materials, paints, varnishes, adhesives, detergents and cleaning agents may then only be produced using CO2 plus hydrogen. The replacement of industrial CO2 emissions thus leads to a further 55,000 km² area for wind turbines, so now we are up to 215,000 km² – much more than half of Germany’s total area.
2/3 of Germany would end up plastered with wind turbines
Two thirds of Germany would now be outfitted with 200-meter tall rotating wind turbines at a distance of 1000m, no matter if there is a city, a river or a highway, a forest, a lake or a nature reserve.
Can we and policymakers imagine such a Germany?
Environmental catastrophe, obstinate policymakers
If you wish to know which effects wind power plants in large numbers have on the extinction of birds of prey, bats, the decline of insects already today, then read it in our book Unerwuenschte Wahrheiten (Unwanted Truths). There you’ll find the hidden fact that wind farms lead to a considerable warming in their area of influence of about 0.5 ° Celsius because the rotating blades compensate for the strong temperature gradient at night and shovel warmer air back to the ground. Numerous studies have shown that the soil in the windparks has dried up considerably.
10-fold higher electricity prices
But politicians refuse to discuss the environmental incompatibility of a massive expansion of wind power plants. Recently the German Bundestag decided that the so-called legal, suspensive effect of objection and action for rescission is no longer applicable to lawsuits against turbines taller than 50 meters. In this way, Germany can be now turned into a single giant wind park without all the annoying objection.
It is almost superfluous to point out that we are talking about astronomical costs. Electrolysis and power-to-gas plants cannot be operated free of charge.
From today’s point of view, one has to expect a tenfold higher electricity price. Any person can imagine the consequences for jobs and prosperity.
Prof. Fritz Vahrenholt
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November 17, 2020 at 08:35AM