10 ms·

My understanding is that, among other things, the generators come under extreme stress during exceptionally windy occasions, causing a lot of wear and tear that

My understanding is that, among other things, the generators come under extreme stress during exceptionally windy occasions, causing a lot of wear and tear that happens way up at the top of these giant windmills. These require a lot of manual maintenance, which is dangerous and expensive due to the nature (and location) of the work. Additionally (and as a demonstration of just how much stress they come under), while coming under said strain, they've been known to burst into flames https://www.youtube.com/watch?v=C_oFPF6Anwo https://www.youtube.com/watch?v=C_oFPF6Anwo As for their lifespan, the government agencies that build them claim 25 years, but there's controversy about this. Searching online will find you conflicting studies, including this one http://www.ref.org.uk/publications/280-analysis-of-wind-farm-performance-in-uk-and-denmark http://www.ref.org.uk/publications/280-analysis-of-wind-farm..., which states "Analysis of site-specific performance reveals that the average normalised load factor of new UK onshore wind farms at age 1 (the peak year of operation) declined significantly from 2000 to 2011" indicating that they may wear out more on the order of ten years. Now that was a cursory search but in any case the argument that the wind farms cost so much to maintain that they're nonviable is not new. Wind turbines aren't exotic tech, but it is a giant turbine that is placed way up on a pole, and fundamentally a turbine will need maintenance, so someone has to go up and do that maintenance, and that's expensive.

Retric 12y ago
Current designs are not standardized, so the worst case is fairly poor. However, economically on average wind is fairly close to Coal Power and in some cases actually cheaper even without subsidies. So, there is no way for it to be a net loss energy wise because electricity is vary cheap energy. PS: For scale wind is on target to hit ~8% of total electricity generation in 2018.
- Agustus 12y ago
  Could you cite sources for the coal to wind economics?
  - Retric 12y ago
    The LCOE can also be regarded as the cost at which electricity must be generated in order to break-even over the lifetime of the project. http://en.wikipedia.org/wiki/Cost_of_electricity_by_source http://en.wikipedia.org/wiki/Cost_of_electricity_by_source Note, wind has gotten much better over time so 2013 numbers look much better than 2006 numbers. Germany levelized cost of electricity generation in 2013 (EUR/MWh) Onshore wind farms 45–107 Coal-fired power plants (brown coal) 38–53 Coal-fired power plant (hard coal) 63–80 Though I may have undersold things for new generation: Regional Variation in Levelized Costs of New Generation Resources Conventional Coal Minimum 87.0, Average 95.6, Maximum 114.4 Wind Minimum 71.3, Average 80.3, Maximum 90.3 IMO one of the more interesting numbers was Wind, onshore Operating Cost (USD/kW) Min 10.95 Max 60.00. That's a wide gap. PS: Granted, these don't seem to account for time value of money but that's often overstated in terms of economic impact. Basically, if you turn 1oz of gold into 2oz of gold for free it's a net gain even if it takes 50 years, time value really just means there might be better uses of your personal money not that something is a net loss.
    - Agustus 12y ago
      Thank you!
cwal37 12y ago
What government agencies are out there mass-building wind? In terms of America at least, that's not how our generation system is set up. Also, the recently-published Wind Vision[1] runs with an expected 20-year lifetime, and starts digging into system reliability specifics on page 70. Wind Vision was a lengthy collaborative process with industry, the labs, and DOE HQ. Good news is that there have been significant reliability gains in the gearboxes, generators, and electrical systems. [1] http://www.energy.gov/windvision http://www.energy.gov/windvision .pdfs are on the right.
jdmichal 12y ago
> Additionally (and as a demonstration of just how much stress they come under), while coming under said strain, they've been known to burst into flames I thought all wind turbines were built with brakes now exactly to prevent this and other more spectacular failure modes, like the blades fragmenting. They have a defined operating range, and if the wind isn't in that range the brakes engage and the blades don't move.
- 69_years_and 12y ago
  Not quite, if the wind is too strong the blades feather (edge on to the wind) brakes exist but are puny and are only for maintenance use. Some blades have a tip that the rotates and causes high drag in the event of feathering failing and going into an overspeed.
reitanqild 12y ago
I think last year I read about an experimental setup that uses lidars to measure incoming wind allowing angle to be adjusted, ideally before the gusts hit. No conclusion at that time though. (The offshore ones are huge and I guess changing the angle can't be done anywhere near fast atm.)

Retric 12y ago

Current designs are not standardized, so the worst case is fairly poor. However, economically on average wind is fairly close to Coal Power and in some cases actually cheaper even without subsidies. So, there is no way for it to be a net loss energy wise because electricity is vary cheap energy. PS: For scale wind is on target to hit ~8% of total electricity generation in 2018.

Agustus 12y ago
Could you cite sources for the coal to wind economics?
- Retric 12y ago
  The LCOE can also be regarded as the cost at which electricity must be generated in order to break-even over the lifetime of the project. http://en.wikipedia.org/wiki/Cost_of_electricity_by_source http://en.wikipedia.org/wiki/Cost_of_electricity_by_source Note, wind has gotten much better over time so 2013 numbers look much better than 2006 numbers. Germany levelized cost of electricity generation in 2013 (EUR/MWh) Onshore wind farms 45–107 Coal-fired power plants (brown coal) 38–53 Coal-fired power plant (hard coal) 63–80 Though I may have undersold things for new generation: Regional Variation in Levelized Costs of New Generation Resources Conventional Coal Minimum 87.0, Average 95.6, Maximum 114.4 Wind Minimum 71.3, Average 80.3, Maximum 90.3 IMO one of the more interesting numbers was Wind, onshore Operating Cost (USD/kW) Min 10.95 Max 60.00. That's a wide gap. PS: Granted, these don't seem to account for time value of money but that's often overstated in terms of economic impact. Basically, if you turn 1oz of gold into 2oz of gold for free it's a net gain even if it takes 50 years, time value really just means there might be better uses of your personal money not that something is a net loss.
  - Agustus 12y ago
    Thank you!

cwal37 12y ago

What government agencies are out there mass-building wind? In terms of America at least, that's not how our generation system is set up. Also, the recently-published Wind Vision[1] runs with an expected 20-year lifetime, and starts digging into system reliability specifics on page 70. Wind Vision was a lengthy collaborative process with industry, the labs, and DOE HQ. Good news is that there have been significant reliability gains in the gearboxes, generators, and electrical systems. [1] http://www.energy.gov/windvision http://www.energy.gov/windvision .pdfs are on the right.

jdmichal 12y ago

> Additionally (and as a demonstration of just how much stress they come under), while coming under said strain, they've been known to burst into flames I thought all wind turbines were built with brakes now exactly to prevent this and other more spectacular failure modes, like the blades fragmenting. They have a defined operating range, and if the wind isn't in that range the brakes engage and the blades don't move.

69_years_and 12y ago
Not quite, if the wind is too strong the blades feather (edge on to the wind) brakes exist but are puny and are only for maintenance use. Some blades have a tip that the rotates and causes high drag in the event of feathering failing and going into an overspeed.

reitanqild 12y ago

I think last year I read about an experimental setup that uses lidars to measure incoming wind allowing angle to be adjusted, ideally before the gusts hit. No conclusion at that time though. (The offshore ones are huge and I guess changing the angle can't be done anywhere near fast atm.)