[kelnos]

In addition to the other objections raised to this comparison (seriously, attempting to compare a non-PV solar farm with residential PV installs is... silly at best), consider that you're not even comparing them in the right way. Ultimately you want to compare the cost per unit energy per unit time, amortized over the respective life of the panels. You also need to compare the cost of maintenance over the life of the panels. And you don't get to say "the residential ones are covered under warranty, so it's free"; someone has to pay for it in the end. When I was looking, all the residential solar installers I talked to would also remove and replace the panels for free when the building's roof needed to be replaced. Again, that's a cost, even if it isn't borne by the homeowner.

Saying that "it cost $X to build this, and that would pay for Y other things" is meaningless.