  Context. We have conducted a 3D MHD simulation of the solar corona above an
active region (AR) in full scale and high resolution, which shows coronal
loops, and plasma flows within them, similar to observations. Aims. We want to
find the connection between the photospheric energy input by field-line
braiding with the coronal energy conversion by Ohmic dissipation of induced
currents. Methods. To this end we compare the coronal energy input and
dissipation within our simulation domain above different fields of view, e.g.
for a small loops system in the AR core. We also choose an ensemble of field
lines to compare, e.g., the magnetic energy input to the heating per particle
along these field lines. Results. We find an enhanced Ohmic dissipation of
currents in the corona above areas that also have enhanced upwards-directed
Poynting flux. These regions coincide with the regions where hot coronal loops
within the AR core are observed. The coronal density plays a role in estimating
the coronal temperature due to the generated heat input. A minimum flux density
of about 200 Gauss is needed in the photosphere to heat a field line to coronal
temperatures of about 1 MK. Conclusions. This suggests that the field-line
braiding mechanism provides the coronal energy input and that the Ohmic
dissipation of induced currents dominates the coronal heating mechanism.
