I agree with you joule. But to be exact, it's not so much an expectation of a 15% return on capital. A 15% return discounted at 15% = 0% return. Thus the current crunch is even worse then you describe. The 15% isn't so much arbitrary but has been accepted as the right value (more or less) for as long as I’ve been in the oil patch (33 years). It supposedly takes into account the borrowing cost of capital. Often it's also used as a ranking mechanism when there are more projects then capital.

Gail -- as far as future maintenance costs of wind turbines including decommissioning, the oil patch does handle such matters fairly well. The cost to decommission infrastructure, such as removing platforms and plugging wells, is always used in the economic analysis (future negative cash flow). And for public companies those same forward expenses are also part of the valuation. Some fudging occurs, of course, but the SEC and capital sources typically require certified estimators to generate these numbers. Your point does make me wonder how inclusive some of the cost estimates for the various alts take into account (or don't) those future deducts from cash flow.

Goes back to an old Texas saying: sometimes the cheapest part of owning a horse is what you paid initially. Such matters quickly come to mind as just last week I paid a vet another $200 for my "free” dog I rescued.