The Experience Solidifier is a tile entity added by Actually Additions. It will store Experience Points (XP). Within the GUI, XP can be stored by inserting Solidified Experience into the slot or by pressing one of the numbered buttons (each number corresponds to the amount of XP to be stored). The Experience Solidifier will convert the stored XP into Solidified Experience automatically, storing both 64 Solidified Experience and excess XP simultaneously. The Experience Solidifier will also collect XP Orbs in a 5 block radius (an 11x11 area).
The recipes requires Emeralds and not Solidified Experience, contrary to the mod's guide.