Usually, two quantified Boolean formulas (QBFs) are said to be equivalent if they have the same truth value for every assignment to the free variables. This notion of equivalence is very coarse-grained in the sense that it considers only assignments to the free variables, but it does not take the models or counter-models of the two QBFs into account. In this paper, we investigate refined notions of equivalences on the solution level to obtain a more fine-grained comparison of two formulas. We show that the problem of checking solution equivalence is PSPACE complete.