Modulation doping, an effective way to dope quantum dots (QDs), modifies the confinement energy levels in the QDs. We present a self-consistent full multi-grid solver to analyze the effect of modulation doping on the confinement energy levels in large-area structures containing Si QDs in SiO2 and Si3N4 dielectrics. The confinement energy was found to be significantly lower when QDs were in close proximity to dopant ions in the dielectric. This effect was found to be smaller in Si3N4, while smaller QDs in SiO2 were highly susceptible to energy reduction. The energy reduction was found to follow a power law relationship with the QD size.