  Context. The solar corona is heated to high temperatures of the order of
10^{6} K. The coronal energy budget and specifically possible mechanisms of
coronal heating (wave, DC-electric fields, ..) are poorly understood. This is
particularly true as far as the formation of X-ray bright points (BPs) is
concerned. Aims. Investigation of the energy budget with emphasis on the
relative role and contribution of adiabatic compression versus current
dissipation to the formation of coronal BPs. Methods. Three-dimensional
resistive MHD simulation starts with the extrapolation of the observed magnetic
field from SOHO/MDI magnetograms, which are associated with a BP observed on 19
December 2006 by Hinode. The initial radially non-uniform plasma density and
temperature distribution is in accordance with an equilibrium model of
chromosphere and corona. The plasma motion is included in the model as a source
of energy for coronal heating. Results. Investigation of the energy conversion
due to Lorentz force, pressure gradient force and Ohmic current dissipation for
this bright point shows the minor effect of Joule heating in comparison to the
work done by pressure gradient force in increasing the thermal energy by
adiabatic compression. Especially at the time when the temperature enhancement
above the bright point starts to form, compressional effects are quite dominant
over the direct Joule heating. Conclusions. Choosing non-realistic high
resistivity in compressible MHD models for simulation of solar corona can lead
to unphysical consequences for the energy balance analysis, especially when
local thermal energy enhancements are being considered.
