“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.
The usual reasons: maintenance costs on the old unused gear, environmental concerns of new construction, locals who don't want it, partnering with a transmission company, partnering with a distribution company, getting the capital to pay for it all & the feasibility of financial return, among many others.
There are hundreds of potential projects like this they could invest in. It's very likely that one of those other projects is way more likely to succeed, so they pick those projects, and take this one as a writeoff. They could possibly still come back to it, but probably not.
Infrastructure to physically carry the energy away from the power station, aggregate it with other stations’ energy, and transmit it safely to the customers who can use it.
To tie in a major new source of energy, you need to make sure the wires and stuff can handle it, which involves physical construction and planning at a level above an individual operator. The US regulator estimates that 2,500GW of clean energy projects, like this one, are already built and stuck in the backlog of interconnection requests.
