@Researcher101, I have used the ~A$2.5m / per MW as a back-of-the envelope valuation measure for the capacity of a wind portfolio. Last week, as an example, Innergex (a Canadian renewable company) paid C$315m for 131MW in France. This equates to a valuation of ~A$2.4m / per MW, with no development portfolio.
IFN has 550MW capacity, at ~A$2.5m per MW, this would value the company at A$1,375m deduct $550m in debt, implies ~A$800m in equity value vs. current market cap ~A$500m. So blue sky valuation is 60% higher, or ~A$1.00 per share (and this ignores the development portfolio).