In order to achieve global energy supply security, environment-friendly, coordinated configuration and efficient use, the development of clean energy is imperative. In this paper, a clean energy development index evaluation index system with four grades is established from the two aspects of clean energy installed capacity and clean energy generation. Based on the improved entropy method of the sub-section and sub-dimension comprehensive evaluation model and the clean energy installed capacity and clean energy power generation of the year of 2013 and 2014, the absolute, the relative and the incremental development index of various categories of clean energy in different countries is obtained, and then the overall clean energy absolute, the relative and the incremental development index of every country is calculated. Ultimately, the clean energy composite development index is obtained. According to the descriptive statistics analysis method and combined with the characteristics of clean energy development in studied countries, 231 countries are divided into four categories: A++, A+, A, Aâ. By changing the weight determination method, the efficiency coefficient entropy method is used to verify the level of clean energy development, and the Spearman correlation of the exponential results calculated by different methods is analyzed. The conclusion is drawn that the top 10 countries in the clean energy development index in 2014 are the United States, China, Germany, France, Spain, Italy, Kenya, the Philippines, Canada and New Zealand. In fully developed countries, the absolute, the relative and the comprehensive development index of clean energy are relatively high. In emerging countries, the incremental development indexes of clean energy are relatively high, and the emerging countries of the clean energy market have great potential for development.
