This handbook deals with various financial instruments, policies, and strategies in a policy-oriented approach for financing green energy projects. Recently, global investment in renewables and energy efficiency has declined, and there is a risk that it will slow further, Clearly, fossil fuels still dominate energy investments. This trend could threaten the expansion of green energy needed to meet energy security, climate, and clean-air goals. Several developed and developing economies are still following pro-coal energy policies. The extra CO2 generated from new coal-fired power plants could more than eliminate any reductions in emissions made by other nations. Finance is the engine of development of infrastructural projects, including energy projects. By providing several thematic and country chapters, this handbook explains that if we plan to achieve sustainable development goals, we need to create opportunities for new green projects and scale up the financing of investments that furnish environmental benefits. New financial instruments and policies such as green bonds, green banks, carbon market instruments, fiscal policy, green central banking, fintech, and community-based green funds are among the chief components that make up green finance. Naoyuki Yoshino is Dean, Asian Development Bank Institute and Professor Emeritus, Keio University. Jeffery Sachs is Director, Center for Sustainable Development at Columbia University. Wing Thye Woo is Professor of Economics, U.C. Davis. Farhad Taghizadeh-Hesary is Assistant Professor, Waseda University.