sendler2112 wrote: ↑Jan 09 2019 7:14pm
3.4 MW turbines on 170m towers is apparently about as big as it gets due to limitations of transporting larger nacelles or blades over roads.
Enercon E141 is a 4,2MW wind power plant built to use and transport onshore. There are newer designs where rotor blades are transported in more than one piece. Towers are already segmented.
35% CF is predicted. Which is 10% higher than the current world average for onshore wind due to the extremely tall towers.
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This would be 83,000 wind turbines in total.
Your numbers are not so different from mine...
Cephalotus wrote: ↑Jan 07 2019 10:22am
For 1,500TWh anual electricity production...
54,000 wind turbines with a average lifetime of 20 years would translate to 2,700 onshore wind turbines every year.
Your number is a bit higher, because you use a bit higher energy consumption, a bit less powerfull wind power plants and a bit lower capacity factor. This cumulates to the difference.
5 rotor diameters spacing between each one to avoid dominoes from a tossed blade, and to reduce wind shadows is 1 per km2.
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83,000 km2 is 24% of the land area of Germany fully populated with wind turbines. But 24% of Germany is not all of adequate wind resources.
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squeezing them to 3 rotor diameters spacing gets it down to 50,000 km2.
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14% of the total land area...
This is where we have differnt numbers and this happens because we calculate area consumption from wind parks differently.
Germany has already 29,000 (mostly smaller) wind power plants installed and most wind parks come at just a few power plants per wind park.
Typical spacing is 5x rotor diamenter in main wind direction and 3x rotor diameter 90° to that which gives you an ellipse.
Simplified you can put 5 wind power plants into such aneEllipse, not just one, see:
more Details on area consumption:
http://www.windenergie-im-binnenland.de ... brauch.php
If you calculated simplified with that 5 wind power plants = 1 ellipse and calculate only the area inside the ellipse as area consumption. For r=126m this would be 10,7ha for 1 wind power plant, so for r=141m I used 13,4ha =0,134km² for one wind power plant.
Multiplied with 54.000 wind power plants this would translate to 7236km² which is 2,0% of Germany. For this scenario (100% energy, not only 100% electricity) I wrote 3-4% instead of 2% because sometimes wind parks are not so idealy spaced, wind over forests needs more area and to have some reserve in the calculation.
So in the end we use a rather similar approach, but just have different opinions about the definition of the area "consumed" by wind parks.
I assume we can both agree that a very significant amount of aera is needed (in densily populated Germany) and someone would be able to see wind power plants from many palces in Germany for such a scenario. Those wind power plants would become a visible part of our daily life as are cars on the road or planes in the sky for example.
The society has to decide if this is acceptable.
I see no alternatives.
To produce 750TWh/a (or 850TWh/a from your numbers) alternativly you would need something around 70 modern large and super expensive nuclear power plants at 1,4GW each (at 7500h/year). Those would be much less visible, but there is no strategy how to get the fuel for those (if this would be a world wide strategy) and at the history of failure rates with an major accident every 10.000 reactor-years would translate to a risc of a catastrophic widespread contamination (which would cost more than the entire energy transition if it hits major populated areas) to 0,7% per year or 30% over 50 years.
I would not board a plane that has a propability of 30% to crash. I wouldn't do that on 10% either, if you say that modern designs are less riscy (which has not been proofed so far)
There is also the problem of cost (modern nuclear has become much more expensive than wind per kWh), the still unsolved problem of waste managment and the problem of cooling. In summer 2018 German nuclear power plants had to throttle because the rivers had too little water. France faces similar problems in hot summers. You could use alternative cooling strategies like most of our lignite power plants do, but those also consume lots of (ground) water.
To build them all in 20 years so that we can start rebuilding them all over again as they wear out is 11 per day. And then start over with rebuilding them all continually at 11 per day forever. For 1/2 of 1/2 of Germany's current energy.
We already have 29,000 wind power plants.
In year 2017 we installed more than 5GW onshore wind. (this is net installation, replacing some old wind power plants is already subtracted)
In my scenario 2,700 wind power plants * 4,2MW would mean 11GW installation per year.
This is double the 2017 numbers and imho definitly not out of the world. I assume German industry could realise that in 2020 if there would be just enough demand for them.
Doubling installation numbers is not something new, why should it not happen again if there would be the WILL to do it:
https://www.windbranche.de/windenergie- ... eutschland