Wind Turbines
This section applies the chapter entitled “The Last Percentages – Cutting Losses” to wind turbines.
The most efficient wind turbines achieve an overall efficiency of 50% (including all electrical and mechanical losses) at certain operating points. About 59% is the maximum that’s possible, as the scientist Betz had already calculated in 1919. This is the physical limit; more is not possible. Compared to the maximum achievable, these systems thus have an efficiency of 0.50/0.59, which corresponds to 83%. That’s darn good.
The press reports that new wind turbines “which are 2 to 3 times more efficient” have been developed. This means that the engineers who had developed them up to now were, according to these journalists and reports, both ignorant and stupid.
But if up to 83% efficiency is being currently achieved, then “twice as efficient” would mean 166% efficiency. Therefore the authors of these articles report about a perpetuum mobile.
Electric Scooters
Electric scooters, as mentioned before, are considered to be “innovative”. Some young guy had simply screwed a motor to a scooter and mounted some batteries on it. A few years ago, the marketing newspaper “Brand Eins” had lifted the young “inventor” into stardom. Nowadays, “young” and “innovative” are used synonymously. This kind of thing caters to a certain “pigeonhole thinking”.
When riding a bicycle, you know that it is easy to roll over when you pull the front brake too hard. This is worse on a scooter, as its wheelbase (the distance between front and rear wheel) is shorter. An article about these scooters can be found in a “Autobild” German car magazine issue from 2019. It had commissioned DEKRA, an official German technical authority like “TÜV”, to measure the braking performance in several models: Most electric scooters have a braking distance of 4 meters starting at 20 km/h. The deceleration can be calculated from it, which is only 3.9 m/s2, and is slightly more than half as much as that of a bicycle.8 Electric scooters therefore do not fit into current traffic conditions, as they do not correspond to the state of the art.
An article in the German car magazine “ADAC Motorwelt” [63], reporting on these electric scooters on over a three full-page spread, is indicative. It particularly mentions the high accident rate of their riders. The deceleration of 3.9 m/s2, the figure that would establish this relation to the state of the art and represents the main causes, is not mentioned.
Before making them street legal, you could also have examined the problems that other countries (like Israel) are having with them, or you could transferred these problems from the time when inline skates were so popular: Ten wrist fractures were being admitted to every hospital of any major city on any fine weekend in Germany.
I’m getting ahead of myself: Why were these scooters still allowed on the road? The reasons are several: First of all, we want to get our young people on the side of politics. The latter also knows that the “energy turnaround” cannot work. These days, communicating politically incorrect facts is not permissible: In this case, everyone, including the politicians, would otherwise be “shredded” by the press. So, you bow to the pressure. This also gives you a stage that you can use to demonstrate to the public that you are an “environmentalist”. “Electro” sounds good and is “politically correct”. That’s the way German decisions are made.
However, cost-intensive wrist operations are no “environmental protection”, but instead counterproductive: these accident victims are being sacrificed to preserve the power of the respective party in power.
Outer Space Transporters
Some thirty years ago, a European research project was launched to compete with the Space Shuttle. It was called “Sänger” (The inventor was Eugen Sänger) and consisted of a sub-stage that was supposed to fly as an airplane up to an altitude of 30 km. On top of it sat “Horus”, which was supposed to separate with rocket propulsion at this altitude and fly into space. Sänger looked like a pointed triangle and was flat. Attached to the bottom were engines that looked similar to those on a Concorde airplane.
Sänger always had to be flown at exactly one angle of attack so that the engines would deliver the thrust that the engineers had actually calculated to the third digit. Let’s say it was 8.735°. The angle of attack is the angle between the longitudinal axis of the airplane and the air flow. The Sänger project was developed further over several years with this in mind. A professor said it had involved “computing orgies”.
An engineer then had the “stupid” idea to ask how this 8.735° could exactly be maintained. Not at all! Because an aircraft never flies straight ahead, but always slightly high/low-high/low. This is called a “phugoid”. Every aircraft engineer learns this when studying “flight mechanics” in college. This is movement is similar to riding a bicycle through the snow and seeing that you are always zigzagging. Going straight ahead is impossible.
The engines thus had no longer delivered any thrust at this angle, and the Sänger project “died”. They didn’t advertise it, but let it sink into oblivion instead. It was a little embarrassing.
Carbon Fiber Concrete
Considered a “major innovation” in Germany a few years ago: carbon fibers that had been cut into small pieces were added into concrete to produce a concrete that is not only pressure-resistant but tensile-resistant as well. But you should know that fiber-reinforced concrete is nothing new. Metal fibers and (special) glass fibers were known at the time. Glass fiber reinforced concrete can even be used to build thin-walled boats.
One had now mixed carbon fibers into the concrete. This certainly works excellently, but it has one big disadvantage: Carbon fibers are about 5 times more expensive than glass fibers. It therefore makes more sense to mix twice as many glass fibers into the concrete in order to create the same material properties. This concrete thus contradicts the basic principles of mechanical engineering: Concrete is a cheap material. Carbon fibers are very expensive. But it is pointless to combine cheap and expensive things because the disadvantages of the cheap material (concrete) cannot be outweighed by the advantages of the expensive material (carbon fibers).
Since being awarded the prize, no one has heard anything more about the material. Experience has shown that, unfortunately, even professionals are now impressed by things like “carbon fibers”. It’s synonymous with “high tech”. Incidentally, cost-conscious people try to avoid high-tech materials as much as possible because these demand big compromises most of the time, which is not to say that they’re superfluous everywhere.
Elbow Pads and Citybike Frames
The same was true for elbow protectors. The “idea” had been born to build these from pure carbon fiber reinforced plastic in order to be “innovative”. But this material is sensitive to impact, shattering almost like glass. The formula “carbon fibers = great = innovative” was applied in this case as well.
Bicycle frames in citybikes frequently suffer from impacts or blows. Carbon-fiber reinforced plastic breaks in the process from “delaminating”. But some people also got the fine idea to build citybikes with frames made from carbon fibers. Research funds are granted for this kind of nonsense.
Summary of the “Spoilsports”
The examples show that no matter how promising a project or new idea may be: When physics provides a single “striking” argument demonstrating that the thing does not work, then you have to accept it. These can be arguments that even professionals haven’t taken into account even though it belongs to their core canon of knowledge, as this aspect isn’t taken into account in the concrete case. It's thus not as in normal life where you are able to circumvent certain problems and difficulties.
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