Optimization of configuration and operation of shared energy storage facilities invested by conventional coal-fired power plants

With the rapid development of new energy power plants (NPPs) in China, installation of energy storage facilities (ESFs) and flexibility improvement of conventional coal-fired power plants (CPPs) are encouraged by government to provide auxiliary service. Compared with flexibility retrofitting, configuration of ESFs may be feasible to improve the flexibility and adaptation of outdated CPPs, which is more sensitive to the investment and economic returns. This study explores the technical and economic features of battery ESFs in a group of conventional CPPs and makes a comparison in three types of modes, including the mode without ESFs, modes with ESFs for their own use, and modes with shared ESFs. An optimization model is established and employed to obtain the best installed capacity and corresponding sharing ratio of ESFs. The optimization results of multiple modes show that ESFs will improve flexibility of CPPs and penetration rate of new energy in general. If the ESFs can be shared between CPPs and NPPs, not only the Equivalent Available Factor (EAF), but also the annual net profit of ESFs will be increased. According to the results of a numerical simulation, CPPs will get the highest net profit if the installed ESFs can be shared with a proportion of 50 %-75 %. This research can contribute to optimizing the configuration and operation of shared ESFs invested by conventional CPPs, and improving cooperation mechanisms of ESFs in the new power system.