Pulsating aurora are common diffuse-like aurora that appear as widely varying patches that blink on and off with periods up to 20 seconds. Rocket and incoherent scatter radar studies have suggested that energies of the responsible electrons are higher than other auroral types. However, there has yet to be a statistical study concerning the quantitative energy content of pulsating aurora. In this work, we analyzed the energy spectrum from 55 events. We obtained this by inverting the electron density profile as measured by the Poker Flat Incoherent Scatter Radar. We compared this to magnetic local time (MLT), AE index, and temporal proximity to substorm onset. There was a small propensity for higher energy fluxes between 2 and 4 MLT, but a stronger trend in relation to both temporal substorm proximity and AE index. We found that with rising AE, the average energy flux increased from 0.56 mW/m^2 for AE <= 200 to 2.24 mW/m^2 for an AE index > 600. Associated, is a spectral hardening where >= 30 keV electrons contribute 13% and 55% respectively. There was also an increase in total energy flux associated with closer temporal proximity to a substorm, although the higher energies remained present for approximately an hour. Our results confirm the high energy nature of pulsating aurora, demonstrate the connection to substorms, and imply their importance to coupling between the magnetosphere and atmosphere.