Improvements in energy efficiency (EE) can deliver a “double dividend” by reducing emissions and helping to protect the environment. Yet, constraints such as limited access to finance and inadequate policy tools and instruments have placed serious limitations on the promotion of EE improvements. In this policy paper, we first highlight the key policy challenges surrounding the promotion of EE financing in support of green innovation and economic growth. Next, we propose policy actions and recommendations to address such challenges and discuss the effectiveness of various fiscal policy tools and instruments that could help promote EE financing, with a focus on the G20.