Calculating energy of electric field

[planesinspace]

Homework Statement

(a) Consider two concentric spherical shells, of radii a and b. Suppose the inner shell
carries a charge q and the outer shell carries -q (both of them uniformly distributed
over the surface). Calculate the energy of the electric field in this configuration.

Homework Equations

The Attempt at a Solution

I was just wondering if this would result in a net charge of zero, thus no electric field? And consequently no energy?

 

[hikaru1221]

There is no electric field outside the shells and inside the inner shell, but how about the space between the shells?