All aspects of the global energy transition - from decarbonization to adaptation - require massive investments of several trillion US Dollars annually. In the respective debates in political economy and beyond, the question of how to mobilize adequate volumes of such ‘green’ finance is central. However, there is little agreement on what constitutes this type of finance and how energy research can employ the concept to critically analyze and evaluate green transitions. In order to advance the conceptual and empirical work on this key issue, I review and describe the main elements of the global landscape of green finance governing its mobilization and proliferation. I first review the major actors involved in the supply and provision of green finance. Second, I evaluate the central instruments of this provision, their volumes and transformative potentials. Third, I analyze key political faultlines and trade-offs in the provision and contestation of green finance, which will shape the coming decades of green transitions. The paper concludes by discussing how this conceptual apparatus can facilitate next research steps.