To my understanding, solar shielding mod is to reduce the hefty toll we take upon flying into a solar flare or star corona, as well as when we get into a storm in hyperspace. The reduction is supposed to be a hefty 75%, so I thought I'd give it a go as I have reached a end-game fleet and after long time returned to my home station with dozens of rare weapons and new hullmods unlocked. So, I've started dabbling in the refit screen. And since my transports are unlikely to have to ever ran away again - I mounted a solar shielding on all of them. 8 destroyer sized combat transports (with hardened subsystems and automated repais), 3 medium tankers (UI +Insulated Engines) and 2 cruiser sized transports (HS+UI+IE). In case of all transports I have dropped hardened subsystems and replaced it with solar shielding (they got good peak time anyway if need be).
Long story short. I have proceeded to test it on the nearest star. What was my surprise to notice the supply drain to be HIGHER than before. I have even reloaded back to save prior to adding solar shielding on 13/30 of my ships. Without it I was taking ~164 supply/sec - after installing I had been drained for a hefty 175 supply/sec.
Unless there's something I don't understand, I would expect a supply drain to be less? Or maybe things like automated repairs on 8 of my combat transports is to blame for that? I'm just confused and this really doesn't seem to work as it should/is advertised on the label.