Integration of a heterogenous nucleation model into a phase-field software enables simulating the complex interaction between nucleation, solute redistribution and latent heat release. Three case studies of microstructure evolution in light metal alloys are presented which illustrate different implications of this interplay. In the first example, the grain-size of an equiaxed solidifying Mg-Al-based alloy was studied under independent variation of the seed distribution and the cooling rate. Furthermore, the individual impact of the solutes Al, Zn, Ca and Mn was investigated and correlated to the growth restriction factor. In the second example, competition between nucleation and growth was studied for the peritectic phase in directionally solidifying Ti-Al with varying Al-contents. The last example of a hypoeutectic Al-Si-alloy is the most complex. Here, frequent nucleation of silicon on AlP particles turned out to be detrimental, because it reduces the growth undercooling required for modification of the eutectic structures.