So wait, it currently affects all energy damage to ship including shields right?
I will say that when I go exploring, I will intentionally setup all of my ships with Solar shielding, both for speed in doing as many missions as possible by storm surfing, but it also gives the side effect of making the only real exploration threat, the Remnants, a bit easier as well. So I consider Solar shielding to be one of the best mods for exploration. (The derelicts are so weak that they're not a threat to anything much and could probably be defeated by a decently piloted Sunder with HIL and two Ion cannons).