  We statistically estimate the conversion rate of the energy released during
an active-region transient brightening to Doppler motion and thermal and
non-thermal energies. We used two types of datasets for the energy estimation
and detection of transient brightenings. One includes spectroscopic images of
Fe xiv, Fe xv, and Fe xvi lines observed by the Hinode/EUV Imaging
Spectrometer. The other includes images obtained from the 211 \AA channel of
the Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA). The observed
active region was NOAA 11890 on November 09, 2013, and the day after that. As a
result, the released Doppler motion and non-thermal energies were found to be
approximately 0.1 \-- 1% and 10 \-- 100% of the change in the amount of thermal
energy in each enhancement, respectively. Using this conversion rate, we
estimated the contribution of the total energy flux of AIA transient
brightenings to the active region heating to be at most 2% of the conduction
and radiative losses.
