Part of the subtext seems to be that constructing these turbines was a greenwashing campaign on Chevron's part. This kind of project helps to bolster the naive impression that these are "energy companies", as one commenter alluded, not just "oil companies". So in a sense these turbines have fulfilled their purpose.

Even more insidiously, the fact that the wind farm is now sitting idle achieves oil companies' secondary goal of making green energy look bad and unreliable. Thus keeping people divided on whether to support other green power initiatives and allowing our reliance on oil to continue. Profits protected.

I don't think I'm giving them too much credit.

"Don't trust an oil company to disrupt their own business model with renewables" seems to be the lesson here.

The government, local, state, or federal, should have the opportunity to nationalize unused infrastructure like this. Give Chevron an opportunity to tear it down or turn it on, but otherwise pay a market rate just like with eminent domain and let the turbines spin.

I'm guessing this was just some greenwashing by Chevron to avoid being forced to actually cleanup their nuclear waste.

  “Partial non-operation occurred because there are transmission constraints
  and firm transmission service in not available to transmit power generated
  at Casper Wind Farm.”

You don't need to know anything else. There's no transmission capacity and nobody wants to pay for it.