Graalbusters here, since everyone loves syense
The light orb has a certain property constructed by the scientists of graal, which enable it to absorb all of the light from the area. Fireflies are the exception, since their organs are what makes them glow, whilst the light orb can only absorb light created from gralat energy, which is what powers your lamp post. (Which is why we don't need outlets or any wires to power your graal tv with 3+ channels).
That's correct, graal's soil receives energy from all the gralats in the ground, that they are what gives power to gralatical components.
Hence, why doomsday theorists, also known as (Insert spar guild name here), have been warning us about how taking gralats from the ground will destroy graal, and when we have no power the land will die. Of course, this is all speculation, since it can't actually be proven.