I'm curious if you've seen increased interest in hardening substations to attacks. I heard a lot about that after the attacks last year but none of the substations in my area are any different.
Unfortunately it boils down to which company owns them and the amount of $$ they're willing to spend. Most new substations being built all have solid walls, for example, rather than the much-cheaper chain-link fence, which helps a little, but not by much for someone who really wants to get in there. Rarely will a company do any cosmetic updates to an already-built substation, so I'm not surprised the ones in your area haven't changed.
The issue for making them more secure as far as I can tell (I'm fairly new to this field, and a designer, not an engineer, so my technical knowledge is still limited) is how volatile high-voltage electricity is. I'm not really sure what could be done to encase a substation against an attack that secures it against an outside projectile, while still being safe for on-site workers. We're talking hundreds of thousands of voltages here, and most substations are ginormous.