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by londons_explore 2766 days ago
Main cost of neodynium:

* Magnets themselves

* Support structure for a heavy generator

* Energy 'iron losses' in magnet hysteresis.

Main costs of superconductors:

* Superconducting material

* Upfront cost of chillers

* Energy loss in chillers.

For bigger and bigger turbines, superconductors will always win, since the material is cheaper, and chiller cost and energy loss scales with the power generated ^ (2/3), whereas the support structure needs to be both taller and stronger so scales with ^(3/2), so superconductors always ends up eventually cheaper.

1 comments

Can you explain where the 2/3 and 3/2 powers come from?
Chiller cost is approximately proportional to the surface area of the generator. The power output of a generator is approximately proportional to the volume.

The mass of a generator is approximately proportional to the volume too. The support structure is proportional to the mass of the generator, times the height of the turbine (actually more than that, but we'll ignore that for now).

The height of the turbine is proportional to the square root of the wind energy collected. (turbine blades can't hit the ground)

Combine all those factors to get the power indices...