The International Energy Agency (IEA), created in the wake of the 1973 oil shock and ensuing energy scarcity, is now 50 years old. Since the 1990s, the relative abundance of fossil fuels has pushed this organization towards renewable energies. This new impetus derives from initiatives taken by the IEA Secretariat and its successive Executive Directors. This chapter examines the shift towards renewable energy within the IEA under the leadership of Helga Steeg in the 1990s until today. Despite most provisions in its constitutive instrument relating to fossil fuels, the Secretariat cleverly built on alternative energy provisions to initiate changes that progressively transformed the IEA from a fossil fuel agency to a clean energy authority. Through these initiatives, the Secretariat provides its members with cash value in a changing world. The incumbent Executive Director, Fatih Birol, pushed the boundaries even further, making the IEA the spearhead of the energy transition despite opposition from fossil fuel producers.