Whereas Spain used to have one of the most restrictive photovoltaic self-consumption (PVSC) regulations in the world, the new regulation (RD-L 15/2018 & RD 244/2019) improves the economic conditions of PVSC systems, simplifies administrative procedures and allows shared self-consumption. We analyze the impact of the new PVSC regulation on residential, commercial and industrial prosumers’ profitability (internal rate of return). We provide a wide range of results that allow us to explore future profitability depending on the evolution of installation costs, the opportunities of shared self-consumption or storage, and even the potential emergence of new business models. We find that all segments obtain now positive profitability in average conditions. Whereas the residential segment has the lowest profitability level, it has the highest potential by decreasing installation costs and increasing the share of self-consumption, given its higher retail prices. Finally, we identify potential new business models by exploiting the prices and costs differentials across segments and maximizing the share of self-consumed electricity. PVSC systems with industrial costs exploiting residential markets could achieve 35% profitability by reaching 75% self-consumption, and even higher than 40% when self-consumption exceeds 85%.