is the equity side, i.e. the valuation of companies that own wind power assets and hope to make a lot of money on the basis of either of two things, taking into account stable cost base (mostly debt repayment):

1. stable revenues (feed in tariffs and other similar arrangements guaranteeing the price for renewable energy): returns are almost certain, and thus valorised as such - very little risk, so project value raises to that of the equivalent of a safe bond, i.e. with similarly lowish return

2. variable revenues, but predicated on market prices for electricity, which are seen as going up. This is a bet on higher oil and/or gas prices, but with a floor of sorts (i.e. the pricve for renewable power will never be less than something which is pretty easy to estimate)

The lending side - which is what pays for the construction of the wind farms - works mostly on the basis of the certain revenues, and thus risk is limited and well understood. Remuneration for banks was getting skimpy, and some terms were getting somewhat aggressive (counting 20 years of revenue instead of 15, for instance) but things did not become completely unreasonable.

In the long run, we're all dead. John Maynard Keynes