[nfnaaron]

"Nope. We'll end up with a lot of old-tech solar that isn't as good as what we'll get by waiting."

No, we'll still get the years of use from the "old tech" while new tech is being developed, partly on the back of what was learned by bothering to develop the old tech in the first place.

What if we decided not to build cars until we developed the Prius? Or computers until the iPhone? You have to go through the stages, tech doesn't happen fully realized without what went before.

[anamax]

> "Nope. We'll end up with a lot of old-tech solar that isn't as good as what we'll get by waiting."

> No, we'll still get the years of use from the "old tech" while new tech is being developed

(NB)-C < (N-k)B'-C in some cases. (Yes, I realize that NB ignores time value of money. For N>>k, that can be reasonable if C is not too large.)

The numbers matter.

> What if we decided not to build cars until we developed the Prius?

What if we didn't invent false choices? (Hint: I'm not saying always wait.)

You're the one insisting that all-in is always the right solution. That's simply false, as is always wait.

The numbers always matter and they're often context dependent. (Example - pretty crappy solar made sense in some situations while it didn't in other situations. Better solar makes sense in some of the latter, but not all. And so on.)

[nfnaaron]

"You're the one insisting that all-in is always the right solution."

I never said the words "all in," and you complained above that I'm not going all in. I'm confused.

In fact I'm opposed to "it must work 100% or it's useless, and if we do it we must do it 100%." I thought that was clear, but I guess not.