Optimization Design For Large-scale Compressed Air Energy Storage System According To Chinese Condition

Currently, with large-scale development and utilization of renewable energy such as wind power and solar power, more and more attention is paid to the electrical energy storage and power grid peak shaving. An effective solution for energy storage and peak shaving can contribute to vigorously develop renewable energy. Pumped-hydro energy storage (PHS) and compressed air energy storage (CAES) are two types of large-scale energy storage around the world. In the regions lacking of water resources, PHS is rarely constructed. However, CAES is low restricted by water resources. Based on the conventional gas-fired power plant, CAES separates the process of air compression and electricity generation according to power grid load, and it is especially suitable for power grid peak shaving.A hybrid-fuel CAES and a coal-fired external combustion CAES are both proposed and analyzed in this study according to the China’s actual conditions, which is rich in coal but short of natural gas (NG). The hybrid-fuel CAES uses NG as part of the fuel for power generation, which can reduce NG consumption. And the coal-fired external combustion CAES only uses coal as the fuel for power generation. The overall efficiency of the hybrid-fuel CAES and the coal-fired external combustion CAES are 61.18% and 48.37%, respectively. Both these two novel CAES system are more efficient than the Huntorf CAES system, which had been under business operation in Germany for decades. Moreover, with the improvement of the device performance and introduction of a recuperator, the exergy efficiency of CAES system can be further improved. The exergy efficiency of the hybrid-fuel CAES is 59.84%, and the exergy efficiency of the coal-fired external combustion CAES is 47.22%. Techno-economic analysis on these two novel CAES system based on the electricity market in North China is also conduct. Since CAES is a new power system in China, its cost of electricity (COE) is a little bit high. However, the CAES power system, which is efficient in electrical energy storage and power grid peak shaving, will be likely to become competitive in the electric market, provided that the energy supplies are improved and the large-scale grid-connection of wind power is realized.