Studying Efficiency Of Coal-fired And Gas-fired Power Plants In China Based On Data Envelopment Analysis

Thermal power is the main form of power generation in China.Coal provides nearly 70 % of generation,so it is important to study the efficiency of coal-fired power plants and the factors that have impact on efficiency.In addition,in order to improve the air quality,the proportion of natural gas power generation began to increase,especially the " coal-to-gas" policy of heating boilers from 2012,which further increased the proportion of gas power generation.This paper applies DEA model to evaluate the environmental efficiency of coalfired power plants,and analyzes the factors affecting the efficiency of power plants by regression model.It not only estimates comprehensive efficiency and cost efficiency of coal-fired power plants and gas-fired power plants but also compared the differences between the two groups.In order to estimate the impact of the " coal-to-gas" policy on the efficiency of thermal power plants,Malmquist index is applied to measure the change of efficiency value.The results are as followed,the efficiency of coal-fired power plants different among regions,which of eastern China is significantly higher than that in the central and western China.In addition,we found that economic development also affect the efficiency.The size of the power plant has a positive impact on the efficiency value.From the ownership perspective,the efficiency of non-state power plants is higher than that of the state-owned ones in central region.A comparative analysis of coal-fired and gas-fired power plants finds that,first,the comprehensive efficiency of gas-fired power plants is higher than that of coal-fired power plants under both natural and managerial disposability;second,the cost efficiency of gas-fired power plants is lower than that of coal-fired power plant with non-inclusion of unexpected outputs;lastly,China's coal price consolidation policy has narrowed the price gap between power coal and natural gas,and increased energy cost efficiency of gas power generation.Based on these results,some policy suggestions are put forward from the aspects of optimizing power production and improving the economic benefits of natural gas power generation.