I came across these near the end of the Grissom Academy mission. What exactly are they for? In the screenshot, you can see that they are destructible and you can shoot them. However, after you destroy them, you can "Reactivate" them and the attached Shield Pylon pops on again.
The battle here is a bit too hectic for me to stop and experiment with them (lots of Cerberus and an Atlas mech), so I've just been destroying them outright. I thought that destroying them may act like a pseudo-Overload, but the Turret next to one I just destroyed didn't seem to take any Shield damage.
Do they shield NPCs in an area around them? What exactly should I do with these? Is there any point to reactivating them?