I dunno, the lingering slivers of "optimist" in me still has hope we'll eventually discover a way to improve PV cell efficiency enough to make them worthwhile at small-to-medium scale. I agree that large scale probably isn't ever going to work, simply because of the massive space that'll still be required. Electrical distribution is lossy already, and I suspect the larger a solar field is, the more inefficient the energy transfer from the panels into the grid becomes, since it has to go from panel-to-panel, then to a chain of transformers, more lines, more transformers, then out to the grid on HV lines where the usual slow loss happens. Plus the maintenance -- somebody has to keep all the panels washed, repaired when wiring goes bad or circuits fail, and replaced when glass gets smashed by the elements, and the usual substation maintenance too.
Still, if we can get PVs to over 60-65% efficiency I think they'll become very attractive for use on industrial and commercial buildings. Lots of mostly-wasted rooftop space just waiting to slurp up some juice.
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