Re: What does this mean for PV?
The minimum does refer to sunspots, and the total energy output of the sun does not vary much, but there is a definite correlation between sunspot activity and global temperature (spanning hundreds of years). The current understanding of the physics suggests that the weaker solar magnetic field during minimum causes more cosmic rays to penetrate the atmosphere, seeding more clouds, which increases Earth's mean albedo.
This correlation between solar activity and global temperature does not necessarily deny the existence of AGW, but no doubt it will muddle (and muddy) the discussion on AGW (yet again). Futile, really, because getting rid of dependence of fossil fuels is a good thing for many reasons besides the warming issue (as many others have noted).
What worries me (a bit) is that I have got myself a load of (expensive) solar astronomy kit, and it would be a shame if the views get boring. On the other hand, nobody knows what the sun looks like in H-alpha during the onset of a Maunder-type minimum, so recording it (IF it happens) is going to be interesting. Even a fairly quiet sun in white light can be full of drama in H-alpha, as can be seen in this shot (with Earth to scale added)