I had some ideas on why the EROEIs may be worse for a larger windmill and started to write down the ideas. I then turned to chatGPT which actually summed my ideas better than I could so here is the chatGPT summary 1-4:
1. Size and components: The E-82 wind turbine is larger than the E-66, which means it might require more materials, manufacturing processes, and maintenance efforts. The larger size could result in increased energy consumption during construction, transportation, and installation.
2. Advanced features and technology: The E-82 wind turbine might incorporate more advanced features or technology compared to the E-66, such as a higher hub height, longer rotor blades, or a more sophisticated control system. These additional features could enhance performance but might also require more energy for manufacturing, operation, and maintenance.
3. Environmental conditions: EROEI can also be affected by the wind resource at the site where the wind turbines are deployed. If the E-82 turbines are installed in an area with lower wind speeds or less consistent wind patterns compared to the E-66, they might need to operate at a lower capacity factor, resulting in decreased energy output.
4. Design choices: Enercon might have made specific design choices while developing the E-82 that prioritized other factors such as increased power output or improved reliability, which could have led to a trade-off in terms of its EROEI.
An obvious problem with wikipedia in this case is that there are no good references. The different papers that were referred to were written between 1998 and 2011 (these numbers are negotiable too depending on which papers we want to include in the comparison).
The E-82 is a much later model than the E-66 so it doesn't seem unreasonable that it contains (please observe that I am guessing here) more features needed for stabilization of the power grid. It is true that power plants must not only provide power to a grid but also other services such as frequency stabilization. Such features would probably add to the cost in terms of natural resources. As Germany and other countries have shut down nuclear plants that have inherently very large rotational masses the frequency stabilization is becoming a problem. An example of the need of big rotational masses is for example the eastern half of the Danish power grid which is stable because it is connected to the Swedish grid which is providing the stabilizing service.
Finally, as Ferg has pointed out many times, EROEI varies a lot depending on how the number was calculated and a 50% difference in EROEIs for these two models is actually less than the enormous spreads in EROEI that would be the result of different and sometimes erratic assumptions on a single model.
I tend to think that we're at a philisophical roadblock in determining a levelised EROEI given the financial incentives for both sides of the 'renewables v. alternatives' coin.
I tend to sway towards the narrative this post incites. It's becoming quotidian to see pro-renewables arguments have arguments that are extricated from any basis of logic. How can one calculate the cost of renewables within Australia and omit the capital costs for transmission entirely.....?
You're right about the significance of the different methods of treating recycling and load factors. One other big impact is the square-cube law where the output of a turbine increases with the square of the blade size, but the material input increases with the cube of the blade size. So, larger turbines are likely to have lower EROEI. I came up with 17.7 for onshore wind and somewhere between 12 and 14 for offshore.
I had some ideas on why the EROEIs may be worse for a larger windmill and started to write down the ideas. I then turned to chatGPT which actually summed my ideas better than I could so here is the chatGPT summary 1-4:
1. Size and components: The E-82 wind turbine is larger than the E-66, which means it might require more materials, manufacturing processes, and maintenance efforts. The larger size could result in increased energy consumption during construction, transportation, and installation.
2. Advanced features and technology: The E-82 wind turbine might incorporate more advanced features or technology compared to the E-66, such as a higher hub height, longer rotor blades, or a more sophisticated control system. These additional features could enhance performance but might also require more energy for manufacturing, operation, and maintenance.
3. Environmental conditions: EROEI can also be affected by the wind resource at the site where the wind turbines are deployed. If the E-82 turbines are installed in an area with lower wind speeds or less consistent wind patterns compared to the E-66, they might need to operate at a lower capacity factor, resulting in decreased energy output.
4. Design choices: Enercon might have made specific design choices while developing the E-82 that prioritized other factors such as increased power output or improved reliability, which could have led to a trade-off in terms of its EROEI.
An obvious problem with wikipedia in this case is that there are no good references. The different papers that were referred to were written between 1998 and 2011 (these numbers are negotiable too depending on which papers we want to include in the comparison).
The E-82 is a much later model than the E-66 so it doesn't seem unreasonable that it contains (please observe that I am guessing here) more features needed for stabilization of the power grid. It is true that power plants must not only provide power to a grid but also other services such as frequency stabilization. Such features would probably add to the cost in terms of natural resources. As Germany and other countries have shut down nuclear plants that have inherently very large rotational masses the frequency stabilization is becoming a problem. An example of the need of big rotational masses is for example the eastern half of the Danish power grid which is stable because it is connected to the Swedish grid which is providing the stabilizing service.
https://en.wikipedia.org/wiki/Electricity_sector_in_Denmark
Oh, I digress.
Finally, as Ferg has pointed out many times, EROEI varies a lot depending on how the number was calculated and a 50% difference in EROEIs for these two models is actually less than the enormous spreads in EROEI that would be the result of different and sometimes erratic assumptions on a single model.
Some good points, Mark.
I tend to think that we're at a philisophical roadblock in determining a levelised EROEI given the financial incentives for both sides of the 'renewables v. alternatives' coin.
I tend to sway towards the narrative this post incites. It's becoming quotidian to see pro-renewables arguments have arguments that are extricated from any basis of logic. How can one calculate the cost of renewables within Australia and omit the capital costs for transmission entirely.....?
https://www.youtube.com/watch?v=W-GwnPWTwmU
Hi Ferg,
I covered the EROEI calcs for onshore and offshore Wind Power here:
https://davidturver.substack.com/p/eroei-eroi-of-onshore-offshore-wind-power
You're right about the significance of the different methods of treating recycling and load factors. One other big impact is the square-cube law where the output of a turbine increases with the square of the blade size, but the material input increases with the cube of the blade size. So, larger turbines are likely to have lower EROEI. I came up with 17.7 for onshore wind and somewhere between 12 and 14 for offshore.