Bluntly the marketing has gotten ahead of the quality assurance and manufacturing capability ( Great comparison with suspension bridges ) This is being driven by bigger and bigger capacity calculations tied to tax breaks . Sadly power deliverables for these projects seldom exceed 20% of capacity .
The failure of this turbine blade was not due to a manufacturing defect as claimed by GE .
These new long turbine blades have been designed to bend and twist as they rotate .
As a result, under every rotation of the turbine blades they are undergoing bending and torsional stresses.
Experimental measurements by the Norwegian government on an offshore wind turbine show that these tall towers can oscillate at low frequencies corresponding to blade rotational speed. This has also been verified by finite element calculations on the current wind turbine towers.
The blade shows the classical torsional fatigue failure profile.
Since these blades are subjected to high alternating stresses, superior construction material must be used. The GE blade was constructed of fiberglass, which has only 1/10 the strength of a high-quality carbon fiber.
To save money, GE did not incorporate any of the more expensive carbon fiber material into their blades as this would also require highly toxic epoxy glues to be used .
All fiberglass constructed blades should never be allowed in any turbines whether they’re operating on land or sea.
Wow this is really interesting. Why was there apparently no oversight committee that had the engineering qualifications to spot and prevent this kind of malfeasance?
I am sharing the comment around. I am a chemist, not a mechanical engineer. But when things fail shortly after being put into service, it's usually a big problem.
When I was reading on the web about "how to build a wind turbine blade," the blades seemed to have a carbon-fiber/epoxy core. Nobody mentioned carbon/epoxy about this blade. But as a non-engineer, I didn't want to say anything about it because the blade did have "webs," which were not mentioned in the carbon-core article I read.
There a good reasons why professional engineers have to pass qualifying tests and show that they are taking classes to keep up their certificates. So I don't go there!
I have been researching the problems with offshore wind turbines for the past two years.
The research laboratory that I directed at the University of Virginia was to develop reliable rotating equipment for the NASA space shuttle program, petrochemical, and power utility industries.
In my 30 years of working with rotating equipment, the offshore wind turbines are the most unreliable equipment I have ever encountered. The reason for this is the high bearing loads encountered during variable wind conditions. As such all wind, turbines must contain massive amounts of highly toxic, synthetic lubricants with extreme pressure additives. The EPA has stated that several gallons of these synthetic lubricants leaking into the ocean can contaminate over 1,000,000 gallons of water.
The first problem with wind turbines is that they must shut down when the wind reaches 55 mph. As such during a winter storm, when you need the energy the most, it will not be available.
The second major problem is the energy is generated by asynchronous turbine-generators. This energy is not compatible with the grid.
That is why the grid operators are slow walked this unstable energy onto the grid.
The grid was designed for the one-way transmission of regulated synchronous energy. If too much of this uncontrollable energy is forced on the grid, It can collapse it and also damage synchronous stationary turbine-generators.
The failure of the turbine blade off of Nantucket is only one of GE’s problems. It is currently being sued for the large number of turbines it has installed in the wind farms in Oklahoma. GE is currently being sued because these turbines have experienced a number of gearbox and generator bearing failures.
WRT synchronous energy, as I understand it, onshore wind farm windmills are interconnected to the wind farm control center using fairly high voltage DC power cables. All that DC power collected at the control center is then converted to AC power which MUST be synchronized to the grid. Some issues right there which Meredith and other have covered elsewhere. Perhaps offshore windfarms use AC to interconnect to individual windmills? Dunno.
Do you have any estimate for the cost differential between the fiberglass and carbon fiber blade? Are we talking about a blade replacement that is 20% more or 2x?
Finite Element Wind Turbine Dynamic Stress Analysis
We now have the capability to compute a complete dynamic vibration and stress analysis of a complete airplane including aerodynamic loads.
What needs to be done is to have a complete dynamic stress analysis performed on these offshore wind turbines before they are allowed to be installed in the ocean.
Such a complete analysis could be performed by a university such as Purdue or MIT.
For example, the recent blade failure of the GE turbine off of Nantucket clearly appeared to be a torsional blade failure due to the flexing and bending of blade.
It has already been shown that these huge wind turbine towers with the heavy nacelles have natural frequency modes in the RPM range of the wind turbine blades .
A complete finite element dynamics and stress analysis of the entire wind turbine, including tower, nacelle and blades should be completed before construction can proceed.
Loading on a wind turbine is caused both by wave and wind action.
What is important to understand is that substantial internal bearing and gearing loads are internally generated by the change of direction of the fan blades due to gyroscopic action .
No further large wind turbines should be installed off of the eastern seaboard unless a qualified complete structural dynamic vibration stress analysis is performed, including what dynamic stresses could occur during a hurricane.
Edgar J. Gunter, PhD
Prof. Emeritus Mech. & Aerospace Eng., University of Virginia
The operational life of land-based wind turbines is already lower than expected, but the stress on sea-based turbines is even larger, not a great outlook for their average life.
This raises 2 key issues:
- The lifecycle costs are much higher than advertised due to more expensive maintenance and replacement of parts
- The amount of waste is becoming a real problem. There’s no meaningful way to recycle wind blades which are made of fiberglass, carbon composite, and foam. Currently, blades just pile up in landfills which are becoming large enough to be seen from space.
Thank you for your Nantucket Wind timeline. Offshore wind is the most expensive form of grid-scale power generation. Since there aren't topographic features analogous to mountain passes to funnel the wind, the capacity factors should be lower than terrestrial wind generation.
Gene, actually the capacity factors for wind turbines offshore tend to be higher than most places on land. Which is not the same as saying that offshore wind is reliable.
Thank you. Given the power output from a wind turbine is proportional to the cube of the wind velocity, the statistics from your previous article are concerning.
That's an interesting energynumbers analysis, especially the CF vs amount of time at a particular CF. Not having the same analysis at hand for onshore I can't be sure just how they compare but it seems to me that the same sort of S curve would be experienced for onshore no?
Thanks for this analysis, Meredith. This story has not received nearly enough national coverage. Unfortunately, California seems all too eager to follow in Nantucket's path:
Its not just GE. Siemens wind division is losing money, I believe because of higher than expected warranty costs, which as you imply, is most likely related to design issues. In machine reliability terms, I believe high Weibull 'infant mortality' rates are directly correlated to inherent design flaws.
what is overlooked that if all whirlygigs built on time, on budget with no defects whatever, power produced will be of little value and great expense. someone is making money at ratepayers expense.
Prior to retirement I managed several plant maintenance teams in addition to Engineering groups. The unreliability of wind turbines aside, it always seemed insane to me to spread your maintenance tasks over hundreds of square miles and hundreds of feet in the air, when you could produce the same power in a thermal plant on a postage stamp footprint. I quit my professional society - ASME - years ago when I realized they were all onboard with this counterproductive Solar and wind BS. As I tell my wife, engineers will design anything they’re told to, but it doesn’t mean it’s the right thing to do.
And they like to claim that nuclear is expensive. At least they operate reliably for 60-80 years without falling apart. How much would wind plus enough battery storage to achieve the same reliable output of a nuclear plant over the same 60-80 year period cost? That number needs to be the actual LCOE for wind.
I agree with you about the engineering, as far as that goes, but I think it understated the challenge. If the challenge is "fly people safely & efficiently from point A to point B," then yes, engineering can and does relentlessly improve commercial jet aircraft designs. The underlying challenge is static, so every technology advance yields compounding gains.
But what if the goalposts were always moving backwards & putting more planes in the air meant flying through more & more routes where gravity & wind resistance kept getting harsher? In other words, rather than a superior travel option, what if flight itself were a grossly inefficient way to travel & became worse with repetition?
That's where it seems turbines have always been. If the options for ideal placement of unreliable energy systems started out poorly and keeps getting worse, then modest engineering improvements will probably yield proportionally negative returns.
Wind energy firms can claim "our machines are 40 percent more efficient!" ... but who cares if they're in a 70 percent less efficient spot.
Well, maybe. Mining has the same issues. Apparently, the Phoenicians who came to Cornwall for tin and copper could pick up nodules just lying on the ground. That’s the story, anyway.
Mining tends to get harder with time, whether it’s tin or wind.
if one believes that CO2 "emissions" are a threat to the environment or "climate" then the last thing one would want to do is erect whirlygigs and sparky billboards for power production.
Time to stop electing those caring representatives in the statehouse and consider filing claims that ponder an opportunity for them to serve in the jailhouse.
Bluntly the marketing has gotten ahead of the quality assurance and manufacturing capability ( Great comparison with suspension bridges ) This is being driven by bigger and bigger capacity calculations tied to tax breaks . Sadly power deliverables for these projects seldom exceed 20% of capacity .
Could you explain what is a "turbine blade liberation event,"? Thanks!
I assume that it is a turbine blade being "liberated" from the wind turbine. In other words...a euphemism for a blade failure.
The failure of this turbine blade was not due to a manufacturing defect as claimed by GE .
These new long turbine blades have been designed to bend and twist as they rotate .
As a result, under every rotation of the turbine blades they are undergoing bending and torsional stresses.
Experimental measurements by the Norwegian government on an offshore wind turbine show that these tall towers can oscillate at low frequencies corresponding to blade rotational speed. This has also been verified by finite element calculations on the current wind turbine towers.
The blade shows the classical torsional fatigue failure profile.
Since these blades are subjected to high alternating stresses, superior construction material must be used. The GE blade was constructed of fiberglass, which has only 1/10 the strength of a high-quality carbon fiber.
To save money, GE did not incorporate any of the more expensive carbon fiber material into their blades as this would also require highly toxic epoxy glues to be used .
All fiberglass constructed blades should never be allowed in any turbines whether they’re operating on land or sea.
Edgar J. Gunter, PhD
Prof. Em. Mech. & Aerospace Eng., UVA
Fellow ASME
DrGunter@aol.com
I am going to share this comment. I think more people need to see it.
Top quality carbon fiber costs 15 times more than fiberglass but it is 10 times stronger.
This is the reason why fiberglass is never used in the aerospace industry, only carbon fiber compositions.
Wow this is really interesting. Why was there apparently no oversight committee that had the engineering qualifications to spot and prevent this kind of malfeasance?
I am sharing the comment around. I am a chemist, not a mechanical engineer. But when things fail shortly after being put into service, it's usually a big problem.
Thanks -- I am interested to learn more about this issue. My background is more policy/statistical analysis, so not an engineer.
When I was reading on the web about "how to build a wind turbine blade," the blades seemed to have a carbon-fiber/epoxy core. Nobody mentioned carbon/epoxy about this blade. But as a non-engineer, I didn't want to say anything about it because the blade did have "webs," which were not mentioned in the carbon-core article I read.
There a good reasons why professional engineers have to pass qualifying tests and show that they are taking classes to keep up their certificates. So I don't go there!
The reason is GE, like Boeing, have been cutting back on their engineering staff to save money.
The reason is GE, like Boeing, have been cutting back on their engineering staff to save money.
Not surprising, but extremely worrying.
Thanks to Meredith for posting this. Just wow. This physics PhD loves being educated by qualified engineers.
Paul,
I have been researching the problems with offshore wind turbines for the past two years.
The research laboratory that I directed at the University of Virginia was to develop reliable rotating equipment for the NASA space shuttle program, petrochemical, and power utility industries.
In my 30 years of working with rotating equipment, the offshore wind turbines are the most unreliable equipment I have ever encountered. The reason for this is the high bearing loads encountered during variable wind conditions. As such all wind, turbines must contain massive amounts of highly toxic, synthetic lubricants with extreme pressure additives. The EPA has stated that several gallons of these synthetic lubricants leaking into the ocean can contaminate over 1,000,000 gallons of water.
The first problem with wind turbines is that they must shut down when the wind reaches 55 mph. As such during a winter storm, when you need the energy the most, it will not be available.
The second major problem is the energy is generated by asynchronous turbine-generators. This energy is not compatible with the grid.
That is why the grid operators are slow walked this unstable energy onto the grid.
The grid was designed for the one-way transmission of regulated synchronous energy. If too much of this uncontrollable energy is forced on the grid, It can collapse it and also damage synchronous stationary turbine-generators.
The failure of the turbine blade off of Nantucket is only one of GE’s problems. It is currently being sued for the large number of turbines it has installed in the wind farms in Oklahoma. GE is currently being sued because these turbines have experienced a number of gearbox and generator bearing failures.
Regards,
Edgar
.
WRT synchronous energy, as I understand it, onshore wind farm windmills are interconnected to the wind farm control center using fairly high voltage DC power cables. All that DC power collected at the control center is then converted to AC power which MUST be synchronized to the grid. Some issues right there which Meredith and other have covered elsewhere. Perhaps offshore windfarms use AC to interconnect to individual windmills? Dunno.
Thanks, Edgar. Appreciate the additional color.
Do you have any estimate for the cost differential between the fiberglass and carbon fiber blade? Are we talking about a blade replacement that is 20% more or 2x?
High-quality carbon fiber can be 15x more expensive than fiberglass. However, carbon fiber has 10x the strength of fiberglass.
This is the reason that only carbon fibers are used in aerospace application and never fiberglass. As the old saying goes,” you get what you pay for”.
"blade failure" sounds more innocuous than "loose football field sized blade flies through the air and lands x feet away." If that's the same thing.
Finite Element Wind Turbine Dynamic Stress Analysis
We now have the capability to compute a complete dynamic vibration and stress analysis of a complete airplane including aerodynamic loads.
What needs to be done is to have a complete dynamic stress analysis performed on these offshore wind turbines before they are allowed to be installed in the ocean.
Such a complete analysis could be performed by a university such as Purdue or MIT.
For example, the recent blade failure of the GE turbine off of Nantucket clearly appeared to be a torsional blade failure due to the flexing and bending of blade.
It has already been shown that these huge wind turbine towers with the heavy nacelles have natural frequency modes in the RPM range of the wind turbine blades .
A complete finite element dynamics and stress analysis of the entire wind turbine, including tower, nacelle and blades should be completed before construction can proceed.
Loading on a wind turbine is caused both by wave and wind action.
What is important to understand is that substantial internal bearing and gearing loads are internally generated by the change of direction of the fan blades due to gyroscopic action .
No further large wind turbines should be installed off of the eastern seaboard unless a qualified complete structural dynamic vibration stress analysis is performed, including what dynamic stresses could occur during a hurricane.
Edgar J. Gunter, PhD
Prof. Emeritus Mech. & Aerospace Eng., University of Virginia
Former Dir. Rotor-Bearing Dynamics Laboratory
Fellow ASME
Sounds like something that should involve parades, flags and fireworks.
Indeed, a “liberation event!”
Yes... corporate babblespeak for "our stuff failed spectacularly."
BP should have claimed Deepwater Horizon was a "Gulf petroleum liberation event."
The operational life of land-based wind turbines is already lower than expected, but the stress on sea-based turbines is even larger, not a great outlook for their average life.
This raises 2 key issues:
- The lifecycle costs are much higher than advertised due to more expensive maintenance and replacement of parts
- The amount of waste is becoming a real problem. There’s no meaningful way to recycle wind blades which are made of fiberglass, carbon composite, and foam. Currently, blades just pile up in landfills which are becoming large enough to be seen from space.
Thank you for your Nantucket Wind timeline. Offshore wind is the most expensive form of grid-scale power generation. Since there aren't topographic features analogous to mountain passes to funnel the wind, the capacity factors should be lower than terrestrial wind generation.
Gene, actually the capacity factors for wind turbines offshore tend to be higher than most places on land. Which is not the same as saying that offshore wind is reliable.
https://meredithangwin.substack.com/p/sea-winds
Thank you. Given the power output from a wind turbine is proportional to the cube of the wind velocity, the statistics from your previous article are concerning.
"Onshore wind speeds form a rather traditional bell-shaped curve, while offshore wind speeds are skewed to the lower speeds. However, the offshore wind speeds are still higher than the on-shore wind speeds. (reference 4, slide 20). This slide is from an early (Feb 20, 2020) DNV report." This implies greater variability in offshore wind power output. One of my colleagues just provided me with UK offshore wind statistics to review. https://energynumbers.info/uk-offshore-wind-capacity-factors and https://www.bloomberg.com/news/articles/2022-06-08/uk-wind-power-waste-leads-to-record-costs
That bloomberg article is paywalled but here's one that's not. https://carbontracker.org/britain-wastes-enough-wind-generation-to-power-1-million-homes/
Thank you, Gene. Excellent link.
That's an interesting energynumbers analysis, especially the CF vs amount of time at a particular CF. Not having the same analysis at hand for onshore I can't be sure just how they compare but it seems to me that the same sort of S curve would be experienced for onshore no?
Thanks for this analysis, Meredith. This story has not received nearly enough national coverage. Unfortunately, California seems all too eager to follow in Nantucket's path:
https://substack.com/home/post/p-146771440?source=queue&autoPlay=false
Its not just GE. Siemens wind division is losing money, I believe because of higher than expected warranty costs, which as you imply, is most likely related to design issues. In machine reliability terms, I believe high Weibull 'infant mortality' rates are directly correlated to inherent design flaws.
https://www.power-technology.com/news/wind-turbine-unit-cost-siemens/#:~:text=The%20problems%20with%20the%20turbine%20units%2C%20stemming%20from,costs%20in%20the%20offshore%20sector%20of%20its%20business.
what is overlooked that if all whirlygigs built on time, on budget with no defects whatever, power produced will be of little value and great expense. someone is making money at ratepayers expense.
Prior to retirement I managed several plant maintenance teams in addition to Engineering groups. The unreliability of wind turbines aside, it always seemed insane to me to spread your maintenance tasks over hundreds of square miles and hundreds of feet in the air, when you could produce the same power in a thermal plant on a postage stamp footprint. I quit my professional society - ASME - years ago when I realized they were all onboard with this counterproductive Solar and wind BS. As I tell my wife, engineers will design anything they’re told to, but it doesn’t mean it’s the right thing to do.
And they like to claim that nuclear is expensive. At least they operate reliably for 60-80 years without falling apart. How much would wind plus enough battery storage to achieve the same reliable output of a nuclear plant over the same 60-80 year period cost? That number needs to be the actual LCOE for wind.
... and NPPs could last even longer! We just don't know yet.
Thanks Grandma! Wonderful piece!
I agree with you about the engineering, as far as that goes, but I think it understated the challenge. If the challenge is "fly people safely & efficiently from point A to point B," then yes, engineering can and does relentlessly improve commercial jet aircraft designs. The underlying challenge is static, so every technology advance yields compounding gains.
But what if the goalposts were always moving backwards & putting more planes in the air meant flying through more & more routes where gravity & wind resistance kept getting harsher? In other words, rather than a superior travel option, what if flight itself were a grossly inefficient way to travel & became worse with repetition?
That's where it seems turbines have always been. If the options for ideal placement of unreliable energy systems started out poorly and keeps getting worse, then modest engineering improvements will probably yield proportionally negative returns.
Wind energy firms can claim "our machines are 40 percent more efficient!" ... but who cares if they're in a 70 percent less efficient spot.
Well, maybe. Mining has the same issues. Apparently, the Phoenicians who came to Cornwall for tin and copper could pick up nodules just lying on the ground. That’s the story, anyway.
Mining tends to get harder with time, whether it’s tin or wind.
Good point
if one believes that CO2 "emissions" are a threat to the environment or "climate" then the last thing one would want to do is erect whirlygigs and sparky billboards for power production.
Time to stop electing those caring representatives in the statehouse and consider filing claims that ponder an opportunity for them to serve in the jailhouse.