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It is well known that photospheric flux emergence is an important process forstressing coronal fields and storing magnetic free energy, which may then bereleased during a flare. The \emph{Helioseismic and Magnetic Imager} (HMI)onboard the \emph{Solar Dynamics Observatory} (SDO) captured the entireemergence of NOAA AR 11158. This region emerged as two distinct bipoles,possibly connected underneath the photosphere, yet characterized by differentphotospheric field evolutions and fluxes. The combined active region complexproduced 15 GOES C--class, 2 M--class, and the X2.2 Valentine's Day Flareduring the four days after initial emergence on February 12th, 2011. The M andX class flares are of particular interest because they are nonhomologous,involving different subregions of the active region. We use a Magnetic ChargeTopology together with the Minimum Current Corona model of the coronal field tomodel field evolution of the complex. Combining this with observations of flareribbons in the 1600\AA\ channel of the \emph{Atmospheric Imaging Assembly}(AIA) onboard SDO, we propose a minimization algorithm for estimating theamount of reconnected flux and resulting drop in magnetic free energy during aflare. For the M6.6, M2.2, and X2.2 flares, we find a flux exchange of$4.2\times 10^{20}\unit{Mx},\ 2.0 \times 10^{20}\unit{Mx}, \hbox{and} 21.0\times 10^{20}\unit{Mx}$, respectively, resulting in free energy drops of$3.89\times 10^{30}\unit{ergs}, 2.62\times 10^{30}\unit{ergs}, \hbox{and}1.68\times 10^{32}\unit{ergs}$.

Calculating Separate Magnetic Free Energy Estimates for Active Regions Producing Multiple Flares: NOAA AR11158