Posted on 12/31/2019 11:04:51 AM PST by Olog-hai
“all rotating machinery is subject to fatigue inducing conditions.”
Yes but if designed strong enough there won’t be any strength-reducing fatigue. For example, you don’t hear of airplane wings falling off any more.
My conclusion is that cost cutting is the culprit.
Come to think of it a helicopter couldn’t legally operate at the altitude and position this windmill occupied...
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That’s true but even if we ignore the fact that one is mobile and one is stationary, the amount of analysis, safety factors, inspections, monitoring, mandatory parts replacement after X number of hours etc. are on totally different levels. And even with all that, helicopters have been known to have problems too.
“I don’t know how easy it is to quickly power down a coal or nuke power plant.”
A friend told me that they need to be powered up and down (heated and cooled) slowly so the thick metal components won’t develop thermal stress cracks.
The benefit of hydro and gas turbines is that they can be started and stopped quickly.
“Neither is competitive without subsidy”
If subsidy is required then they are not competitive.
A subsidy might be a good idea to get some devices built to prove concepts, but a permanent subsidy is taxpayers getting cheated.
” highly stressed rotating machinery “
A 1/4 inch bolt and nut with a ton of force applied to it would be highly stressed. A 1 inch bolt would not
Yes but if designed strong enough there won’t be any strength-reducing fatigue.
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The fatigue conditions will still be there.... however yes, you can build it to handle the fatigue. However, that has all kinds of design ripple effects and these usually work from the inside out. First the blades have to be heavier and/or higher strength material. This then means that the shaft and bearings have to be bigger and lastly, the entire support structure all the way down to bedrock has to built heavier to carry the load.
Alternatively, the blades just will have to be replaced on a regular basis. As a slight detour, this in fact is what is happening with large horizontal axis IWTs.... it seems that every day there is another landfill site spouting off about how their space is being all used up with blades that are only a few years old but are already up to their fatigue limit.
So is cost cutting the culprit? Another way to put that is to say that if turbine was to have all the analysis, factory QC, inspections, monitoring, mandatory parts replacement after X number of hours etc. that would be required to give an acceptable safety factor, the costs would naturally be much higher. So in my opinion, this isn’t just about cost cutting but the fact that nobody would want to pay say 10 times as much for something that is already useless..... unless of course the whole thing is subsidized proportionally for the higher amount.
The issue here isn’t just stress.... fatigue is the result of the combination of stress and cyclical loading. And if nothing else, wind turbines are subject to cyclical loading as a result of going up and down like a yoyo all day long. The only other option is for the material to be so lowly stressed that it’s below its endurance limit.
Electric vehicle are not terrorists!
Maybe the windmill didn’t fail. Could it have been the mounting? It was installed on top of a parking garage. I’d look at the structural details is what the windmill was bolted to.
No, I had no graph in mind. But thanks for the info anyway. I just know from watching the wind turbines while trucking near them, that simply feathering the prop blades shuts one down in a couple of minutes.
As one that was raised on a nw IL farm, and farmed until 47 yrs old, the area 30 miles east (Henry Co.) just doesn’t fit the view I would want to see everyday: wind tubines.
There was talk of more coming to the west (southern Mercer Co., where I lived). I wasn’t thrilled to hear that. But now in the wooded hills of SE Lewis Co TN, I’m not worried about my view being ruined any more.
Oh, da hughmanity!!!
Don’t think that theory jives with the video footage of it failing....
I was thinking of the means of throttling power output, until your post, I hadn’t given it much thought in life, and became curious. That seemed to explain it.
I live near a large man made reservoir carved into the top of a mountain. During the night, when energy is cheaper and more available, they pump water into the reservoir to fill it.
During the day, when more energy is needed, they drain the reservoir and generate hydroelectric power as it drains.
Interesting that someone figured that would make money.
Just read another article on this failure.... it had only been up for three weeks. I think that rules out fatigue as the failure mechanism.
Oh hell yeah! You probably recall the Pan Am building helipad disaster in Manhattan that ended helipads on top of buildings in NYC.
Quote of the year, IMO.
We should hurl it at every Greenie we meet.
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