  Solar active regions are driven dissipative dynamical systems. The turbulent
convection zone forces new magnetic flux tubes to rise above the photosphere
and shuffles the magnetic fields which are already above the photosphere. The
driven 3D active region responds to the driver with the formation of Thin
Current Sheets in all scales and releases impulsively energy, when special
thresholds are met, on the form of nano-, micro-, flares and large scale
coronal mass ejections. It has been documented that active regions form self
similar structures with area Probability Distribution Functions (PDF's)
following power laws and with fractal dimensions ranging from $1.2-1.7$. The
energy release on the other hand follows a specific energy distribution law
$f(E_T)\sim E_T^{-a}$, where $a \sim 1.6-1.8$ and $E_T$ is the total energy
released. A possible explanation for the statistical properties of the
magnetogrms and the energy release by the active region is that the magnetic
field formation follows rules analogous to \textbf{percolating models}, and the
3D magnetic fields above the photosphere reach a \textbf{Self Organized
Critical (SOC) state}. The implications of these findings on the acceleration
of energetic particles during impulsive phenomena will briefly be outlined.
