Research on total factor energy efficiency in China based on super efficiency grey DEA model

The traditional evaluation models of energy efficiency often only involve energy consumption and economic outputs, but neglect environmental impact of energy and substitution effect between energy and related factors. Under the frame of total factors energy efficiency, undesirable outputs and related factors about energy are considered, and then a new evaluation model of energy efficiency is established in this paper based on super efficiency grey DEA model. The empirical research using panel data during 1995 and 2005 shows that China's overall energy efficiency is low and has a slow downward trend after maintaining a certain level. Also, regional differences regarding energy efficiency are significant.