Yeah. The majority of the solar system is the sun so I'd imagine it'd be super powerful. Not to mention it's also far away so I can't imagine a wizard being able to draw energy from them very easily. Better than just being a spirit bomb, you might want to limit power-draining using distance. Power might also come from emotional investment for instance a stuffed toy that someone's had since childhood might be more powerful than a new doll just sitting on the shelf no one in particular cares about.

Not explanations, just suggestions.