The study aims to test the nexus of green financing with renewable electricity generation and energy efficiency. The study used data envelopment analysis (DEA) technique during the year of 2016 to 2020 in developed and developing countries. The findings show that there is a 24% possibility of worldwide rise in expenditures in renewable energy through energy efficiency projects and probably could fall around 17% much further in 2017 and 2018. This may jeopardize the Sustainable Development Goals (SDGs) and the Paris climate change agreement. Lack of access to private financing slows the development of green initiatives. Now that sustainable energy is not about science and technology, it is all about getting financing in developed and developing countries. As policy measure, the study suggested to value environmental initiatives, like other infrastructure initiatives, for greater electricity generation and energy efficiency in developed and developing countries. Such infrastructural projects need long-term financing and capital intensiveness. It is further suggested to sustain growth, development, and energy poverty reduction, and around $26 trillion would be required, in terms of green financing, in the developed and developing countries alone by the year 2030 to enhance energy efficiency. To achieve energy sustainability goals in developed and developing countries, recent research suggested some policy implication considering the post COVID-19 time. If such policy implications are implemented successfully, there are chances that green financing would make energy generation and energy efficiency effective.