Decarbonizing electricity is the most effective measure to mitigate climate change. Technological developments have reduced the upfront costs of renewable energy, facilitating a transition to a lower-carbon energy system, especially in latecomer countries. Yet, the pace of solar and wind energy deployment varies across developing countries. In this dissertation, I analyze when and how states expedite a rapid deployment of large-scale solar and wind energies in emerging economies with electricity sectors that have been fully or partially privatized. Effective greening policies work on the binding constraints for private clean energy investments by dissolving previous policy structures. They must re-regulate electricity sectors to remove the sufficient conditions for green policy failure. The design of such broad greening policies is endogenous to the type of electricity sector that emerged from previous market reforms. In firm-captured sectors, greening policies need to deconcentrate them; in government-captured sectors, greening policies must deregulate them; and in state-owned sectors, greening policies have to liberalize them. Each type of greening policy accounts for the actors who pay the economic and political costs of energy transitions and the type of government that adopts it. Deconcentrating greening policies have concentrated costs since they directly harm incumbent private producers who see their share in the market reduced by the entrance of new firms. Deregulating greening policies lead to diffused costs across consumers, who pay higher electricity prices to cover producers’ initial investments. Liberalizing greening policies have diffused costs that harm consumers and (mainly) incumbent state producers, who must compete with private utilities. Leftwing governments are more prone to adopt broad policies that harm private producers, while rightwing governments implement policies that affect consumers or hurt the interests of state utilities. Both types of governments adopt these costly policies at the beginning of their administration to prevent the mobilization of those harmed by the reforms. I test these arguments by analyzing the cases of Argentina, Chile, and Mexico through a historical analysis combined with causal inference methods.