Bakken You are right. Anything but a newly commissioned project is more complicated to analyze and project into the future.
Unlike a new project where you can know EBITDA in advance for 20 or 25 years, the older ones are more difficult because they require more assumptions AND could have wrinkles in the offtake agreement about renewal escalators (or not)...and then you have to model capex for new turbines on some basis over time (or all at once).
We should expect that this is what the interested industry players are doing, once they have their lawyers and operations people study the contracts, performance data, the sites, etc.
It is also why it is very difficult to assign a price for land, permitted or unpermitted, that has a good wind resource. IMO, one of the reasons wind development companies have had a difficult time in the market is because of these valuation difficulties and the fact that they rely on time-limited and ultimately unreliable subsidies from Govt., which cannot afford to even pay for purely govt. operations without borrowing money to do so.