An important problem that has attracted significant amount of attention within the context of energy transitions is the carbon lock-in: a situation in which energy systems are locked-in to high carbon technologies through a path-dependent process. Several measures to avoid the carbon lock-in involve technology-specific measures, which in turn implies that those measures may result in an energy system locked-in to certain low carbon technologies. We consider that the Brazilian system needs policies to escape the carbon lock in, which are based on providing incentives to low carbon technologies. We develop an analytical framework to analyze the role of regulatory institutions in the possible lock-in to utility-scale photovoltaic, in the sense that they create barriers to the adoption of distributed-generation photovoltaic. We show that the definition of a process to adapt the institutional framework in a context of stress in the innovation system is crucial for the adoption of new technologies. Applying our framework to the Brazilian power sector, we observe that only when regulators consider the possibility that the system is locked-in to centralized production technologies (and not when they just consider the carbon lock-in) they manage to eliminate barriers to distributed generation based on solar PV.