We present a study comparing the energy carried away by a coronal mass ejection ( CME ) and the radiative energy loss in associated flare plasma , with the decrease in magnetic free energy during a release in active region NOAA 10930 on December 13 , 2006 during the declining phase of the solar cycle 23 .
The ejected CME was fast and directed towards the Earth with a projected speed of \sim 1780 km s ^ { -1 } and a de-projected speed of \sim 3060 km s ^ { -1 } .
We regard these as lower and upper limits for our calculations .
It was accompanied by an X3.4 class flare in the active region .
The CME carried ( 1.2–4.5 ) \times 10 ^ { 32 } erg ( projected-deprojected ) of kinetic and gravitational potential energy .
The estimated radiative energy loss during the flare was found to be 9.04 \times 10 ^ { 30 } erg .
The sum of these energies was compared with the decrease in measured free magnetic energy during the flare/CME .
The free energy is that above the minimum energy configuration and was estimated using the magnetic virial theorem .
The estimated decrease in magnetic free energy is large , 3.11 \times 10 ^ { 32 } erg after the flare/CME compared to the pre-flare energy .
Given the range of possible energies we estimate that 50–100 % of the CME energy arose from the active region .
The rest of the free magnetic energy was distributed among the radiative energy loss , particle acceleration , plasma and magnetic field reorientation .