Recently, a major breakthrough has been made in the field of research and development of the Compressed Air Energy Storage (CAES) system in China, which is the completion of integration test on the world-first 300MW expander of advanced CAES system marking the smooth transition from development to production. This pioneering achievement is independently developed by the Institute of Engineering Thermophysics of Chinese Academy of Sciences (IET) and Zhong-Chu-Guo-Neng Co. Ltd.
Energy storage technology serves as the key supporting technology for the ongoing energy revolution, while the relevant industry gradually evolves into a pivotal pillar within the spectrum of national strategic emerging industries. In this context, CAES has distinct merits of large-scale, cost-effectiveness, high efficiency and eco-friendliness etc., which is one of the most promising large-scale energy storage solutions. As for the core component of CAES system, the development of expanders emerges with such intricate technical challenges as substantial loads, copious flow rates, intricate flow and heat transfer as well as the demanding wide- operating-gamut with uncompromising efficiency. After years of unremitting efforts, the R&D team of IET has successively resolved key technical problems in breakthrough technologies including intricate 3D design implementation, sophisticated shaft architectures, and dynamic adjustment and control mechanism etc., and developed world-first multi-stage high-load 300MW expander of advanced CAES system endowed with completely independent intellectual property rights. (See Figure 1)
Figure 1 The world-first 300MW advanced CAES system expander
On August 1st, 2023, IET and Zhong-Chu-Guo-Neng Co. Ltd accomplished a significant feat, that is, the successful integration test of a 300MW compressed air expander. Notably, all results of various tests not only met but exceeded the design indexes, highlighting attributes such as exceptional integration, high efficiency, rapid start-stop capabilities, extended operational lifespan and simplified maintenance. The successful development of the 300MW compressed air expander stands as a significant milestone in domestic compressed air energy storage domain. Not only does it mark a turning point for advanced compressed air energy technology, but it also propels the nation's capabilities to unprecedented height. This accomplishment underscores China's commitment to innovative energy solutions and signifies a crucial step forward in the evolution of advanced compressed air energy storage technology.
As the earliest domestic institution in the research on compressed air energy storage, IET has already set up a research and development system with complete independent intellectual property rights through 19 years of efforts. IET successively achieved breakthroughs in critical domains such as comprehensive system design and control across all operational conditions, multi-stage high-load compressors and expanders, and highly efficient supercritical heat storage and transfer etc. These accomplishments bore fruit in establishing the world-first advanced CAES systems, such as the 1.5MW model in 2013, 10MW model in 2016 as well as the groundbreaking 100MW model in 2021. Incorporating the pioneering CAES technology of the IET, Zhong-Chu-Guo-Neng Co. Ltd has the full set of capacities in research and development, design, manufacture, project implementation, investment and operational management of 100 MW level CAES systems. This multifaceted prowess positions the company as a prominent trailblazer and global frontrunner in the realm of advanced CAES systems. Since the advent of their partnership in 2018, both sides have taken the lead in the development of the world-first 300MW advanced CAES system.
The scale-enlargement of CAES systems constitutes an important way to reduce cost, improve efficiency and enhance market competitiveness. Compared with the 100MW advanced CAES system, the forthcoming 300MW system will achieve a threefold amplification in scale, notable 20%-30% reduction in unit cost and a marked 3-5% enhancement in overall efficiency. The successful completion of integration test and subsequent deployment of the 300MW advanced CAES system expander marks the significant progress in the national demonstration project of world-first 300MW advanced CAES system development.
The accomplishments described above have received robust support from the National Natural Science Foundation of China, the strategic pilot project of the Chinese Academy of Sciences, and the national key research and development programs.