I just finished doing a back-of-the-spreadsheet model of filling the global post-peak oil shortfall with electricity. Of course the uncertainties in such a model are enormous, but I'm satisfied that it shows something approximating reality. The executive summary goes something like this:

"If we want to replace any significant proportion of the oil energy we'll be losing with electricity from sources other than coal, we'd better get innovating in a big way, because the curves from PV and wind aren't going to come anywhere near the probable depletion curve at the rate we're going."

With innovation, as with simple capital projects, we face a timeline problem. Ideas take time to implement and more time for the implementations to have an impact. Even if you take the cornucopian view that we're generating all the good ideas we need right now, it will still take time to put them into practice.

All the post-peak decline models that seem realistic to me say we have until 2020 or so before things get really crunchy. That means we have 15 years to hatch our bright ideas, transform them into technology, cost-engineer them so that people other than Bill Gates will benefit, and diffuse them into the economy. All in an environment of ever-tightening energy supplies and increasing geopolitical disruptions.

Faced with that, I'm inclined to say that what we have right now is all we're going to get in the near term. To paraphrase Disgraced Donald, we will to go to war with the innovations we have, rather than the innovations we want or wish we had...

model of filling the global post-peak oil shortfall with electricity

Does your model also adjust for creating H-C chains to ack as a feedstock for all the stuff 'we' are used to having?

we'd better get innovating in a big way,

One minor problem - any energetic source used to power some form of 'electricity harvest' has the potential of being used as a bomb. So if 'we' create a "Mr. Fusion", such a device strikes me as a tool for destruction. Given how well humans treat other humans, Getting what one wishes for might be bad for habitation on the planet or the planet itself.