Superheated Superconducting Granule detectors are presently being developed for the detection of neutrinos and cold dark matter candidates, double β decay experiments and X-ray imaging. The detector pulse height due to a particle interaction depends on the applied magnetic field and the granule volume, but does not depend on the deposited energy. An energy resolution can be obtained by comparing the superheating field distributions before and after irradiation, or from the count rates at different detector thresholds. A description of these two methods, the formalisms to calculate the energy spectra and applications to experimental data are given. Limits on the energy resolution and on the validity of the methods are discussed.