Photovoltaic (PV) systems have reached annual installation volumes of >100 GW and a cumulative installation volume of >500 GW. This market is dominated by crystalline silicon (c-Si) technologies that have seen a tremendous cost reduction in recent years and a significant increase in power conversion efficiency (PCE), making the technology competitive on a basis of levelized cost of electricity (LCOE) in many regions of the world. However, while the practical efficiency limit for c-Si might be reached in the coming years, a technology permitting PCEs of 30% or higher will be esential to further reduce the cost of PV systems. We estimate that industrial c-Si PV modules may reach a price level of about 15 c$/W in 2030 at a PCE of 22-24%, with an expected lifetime of 30 years and an annual degradation of 0.5%. To overcome the PCE limit of c-Si modules in production, perovskite on c-Si tandem modules currently seem to be the most promising candidate. For commercial relevance, it is expected that tandem cell and module efficiencies need to be further increased to reach ca. 30% module PCE, and that such modules need to match lifetime and degradation rate of c-Si modules.