How Sustainable is Coal Power Generation in China? A Joint Application of Energy, Emergy and Carbon Accounting

The performance of a power generation process is most often evaluated in terms of energy efficiency and emissions. Emissions generated by coal-fired power generation are among the main sources of pollution (CO2, dust and acid gases) in China and other coal-intensive countries worldwide. However, this is only the downstream aspect of a coal plant performance, where focus is most often placed on GHG emissions and carbon footprint. The upstream side, related to the environmental quality of input resources is also of paramount importance and can be dealt with by means of emergy accounting methods to generate environmental footprint indicators. We evaluate in this study both upstream and downstream aspects of a coal-fired power plant, jointly applying energy and emergy methods to a case study of a 2 x 600 MW supercritical power generation plant in China. The investigated power generation system is equipped with dedusting and desulfurization systems, in order to capture most of the pollutants generated by the combustion process. The ecosystems services needed to abate the remaining fraction of released chemicals are assessed and used for the calculation of energy and emergy performance indicators, with and without including costs and benefits from the dedusting and desulfurization systems. The need for buffer land around the plant to compensate both the CO2 emissions (in the order of 850 g CO2/kwh) and the intensity of the emergy loading is discussed in the paper. A sustainability calculation procedure is developed accordingly.