Question: Impact of EMP on Solar PV

[Skvez]

PV cells are similar to diodes but they're not "little", in semiconductor terms they're gigantic. Bigger is safer when it comes to diodes vs EMP.

I have never seen a PV array with a "bypass diode" for each junction of the array, they have output diodes to stop current flowing into the array (for instance if you have two arrays in parallel). This diode may offer some protection against an induced Voltage in the PV array wiring damaging the PV array itself. You could certainly replace this series diode with one of similar Amp rating but as high Peak Inverse Voltage as you can find.
A Silicon diode initially fails to short, then if enough current flows through the substrate it will melt open cct. Adding a fuse between the battery and the solar panel is unnecessary under normal operation but might help save your PV array in the case that an EMP destroys the protection diode and the shorts the battery through your PV array. On the other hand the PV array may be destroyed before the fuse had time to heat up and melt (still for the cost of a fuse it's probably worth trying, every little bit helps).

The EMP doesn't generate a Voltage, it emits a field that induces a Voltage based on the coupling between the field and the 'wire' it encounters.
Your generator is at risk because the windings are a very long wire all wrapped up into coils and the output of the generator is connected to potentially miles of load wiring.
In contrast the wiring connected to the solar cells is probably only tens of meters and so the induced Voltage could be order of magnitudes lower than that experienced by a generator beside it (the "1500V" you mention).

If the PV cells blow open or short your array is toast (I suppose you could break it up into individual cells in the hope that some of these survived and could be re-connected into a useful string).