Posted on 11/27/2018 3:07:03 AM PST by dennisw
“Could some engineer clue me in on why 20 years is a limit?”
Me too. I agree with you. Something else is up.
Unlike most everything else in the energy generation biz these things are built like disposable lighters. Take the rotor bearings for example; each rotor has a servo motor constantly adjusting the pitch. The rotor is mounted to a bearing that is about five foot in diameter, and a cheap sheet steel race holds the bearings in place while the whole thing is contained with grease seals.
With time and wear the bearings work past the race and it cuts the grease seal spewing grease over a large area. As I understand it these wind turbines are all foreign made and come with no manufacturer warranty of any kind.
Perhaps it is to hard to take the heads off to repair and they trash them in the process?
Flying a small plane over the country opened our eyes to the miles and miles and miles of these ugly wind farms. We had no knowledge how much of the country is littered with these things and probably 60-70 percent are not spinning.
I went on a boondoggle from New England to Nebraska a few years back, just to see America, and drove back on route 80 through Iowa. There was a windmill farm that seemed to go on and on for miles, but that whole time, I only saw two actually spinning (that I saw)
It looked like a giant waste to me. I don’t know how well windpower actually works, though. It is possible I may have gone through when something was going on maintenance wise.
Or something.
Just how many birds does a windmill kill in a 20-year span?
It doesn’t raise a red flag for me from a mechanical perspective.
These are large structures with moving parts, and one can make the parallel to turbines turned by moving water for hydroelectric, but there is a key difference (this is just my opinion, perhaps someone with more knowledge could opine on this)
A hydroelectric turbine is a very static piece of equipment, built on an extremely stable foundation of concrete, and the flow of water into the turbine is likely regulated and controlled to make it as even as possible.
A Wind Turbine is built on a long stalk, and is subject to a huge variation in pressure from the wind, ranging from no wind at all to wind blowing at 60-70 mph. Furthermore, that wind is often not constant, so the gusting and change is going to dramatically change the forces and pressures, often within seconds from low to very high.
I can only imagine that pattern of stress is far, FAR more damaging to the long term reliability than a hydroelectric turbine that is extremely stable.
What is “up” is the height of the mechanical parts. 50’ in the air doesn’t lend itself to frequent maintenance. Many leak oil. If something goes wrong they lock the blades. Think of the torque with a locked, huge blade 50’ high in a windy place.
See my post above at #27. The more I think about it, the more I am convinced that the dynamic variation of forces on the mechanism is responsible for the seemingly short shelf life.
I also think that the nature of the manufacture of these things as you alluded to is also the issue. There is probably much disagreement in the industry about the approach to solving engineering issues associated with those stresses...some better, some worse.
I have heard it said that engineering is all about compromises. That may be true, depending on how “compromises” is defined.
The questions you are asking are entirely legitimate (are you an economist?) but perhaps a bit too analytical for some of the people participating in FR. It’s clear that you are not advocating subsidies.
And most of them are also connected to the grid. When there is no wind to spin them, they have a motor that slowly rotates the blades so gravity doesn’t warp the shafts. The motor is drawing energy off the grid.
Similar to a photo of an electric bus being recharged by a large commercial diesel generator.
It’s all just a big scam.
Love the boondoggle term too. I have a couple long two-lane highways I’d like to explore and boondoggle is the correct term. One goes cross country.
I do believe they have an a cycleing shut off and on cycle. So many hours on and so many hours off, probably something like four on and four off. Not sure, I asked some people in the some area of extreme west Ohio boarder area about why so many of them were not turning and that is what they told me. Also I think they told me they don't turn at night, but I may be wrong about that. There are millions of them in the flat area of the Ohio and Indiana area boarder area. In fact the flatest county in the United States is I think Van Wert County Ohio or the county that Van Wert is in.
https://nawindpower.com/wisconsin-public-service-says-goodbye-to-lincoln-wind-farm
This is not because the turbines are too old. These are small V47 660kw turbines and there are only 14 of them. The “farm” is not viable economically. Current wind turbines have 100ish meter rotors and are rated at about 2-3mw and the wind farms are more like a 100 turbines. Iowa has many such wind farms.
But the batteries only last 7-10 years. Same goes for electric cars. Whatever savings you get from reduced fuel burn you will spend when it's time to replace the batteries.
A good article on the operation and maintenance costs and lifespan of a turbine.
https://www.wind-energy-the-facts.org/operation-and-maintenance-costs-of-wind-generated-power.html
“Due to the relative infancy of the wind energy industry, there are only a few turbines that have reached their life expectancy of 20 years.”
Here was my route:
I had planned to drive out the the Four Corners Monument, but I realized when I reached Louisville, KY that I needed a few more days to do that (which I didn't have) and said to myself "I've never been to Nebraska..." so I closed my eyes and put my finger on a map and that was where I went.
Actually, I had to do that twice.
When I looked at the history of the place I had originally put my finger on, it was famous for some transgender guy who was murdered, and that was about it, so I chose again...Tecumseh, NE was much more interesting...and smaller!
I had no idea. Ugh, that makes it even worse.
There are plenty of websites dealing with wind power and the rapidly advancing technology and the rapidly falling price.
Windmills in the Netherlands have lasted hundreds of years pumping water. The blades are almost as large as electrical generating windmills. The 20 year limit is engineered based on construction methods. Build them fast and relatively cheap and do that every 20 years.
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