Energy density is given by

Energy density,

Where

U is the energy density of the solenoid

B is the magnetic field intensity of the solenoid

is the permeability of the free space.

In the solenoid, energy is stored in the form of magnetic field. For the constant flow of current, the magnetic field inside the solenoid is uniform. So, the energy density in a solenoid is constant. Nothing is greater. The energy density at all the points inside a solenoid is the same.