The Past, Present, and Future of Flywheel Energy Storage

Dear Colleagues,

Flywheel energy storage (FES) technology has been developing over the past fifty years. Large and/or converter power permanent magnet motors make it possible to speed up and slow down flywheels efficiently and reliably, giving continuous momentum for the development of FES worldwide.  The stored energy has reached 100 kWh in a single flywheel energy storage unit, with the charge/discharge power exceeding 1000 kW and the cycle efficiency of the AC terminal of the flywheel energy storage system (FESS) being around 88%. The 20MW flywheel energy storage power station in the United States has been in operation for more than 10 years, and the first Chinese combined 22MW flywheel-to-thermal-power AGC power station was built and put into operation in 2023. Recently, the application of FES, whether independent or mixed with lithium batteries, focuses on the flexible regulation of new energy power, developing beyond past applications such as dynamic UPS, rail transit energy recovery, and frequent peak shaving of independent energy systems.

Before 2010, research on flywheels had been mainly carried out in the United States, Europe, and Japan. In recent years, the Chinese have joined the group and become a major player. In China, in addition to the research on FES supported by the Ministry of Science and Technology, major industrial groups have been developing FES prototypes for different applications. Flywheel energy storage technology in China has reached the stage of small-scale industrialization in demonstration with the support of industrial capital.

There are three trends in the future research and development of FES. Firstly, it is necessary to accumulate fatigue characteristic data for flywheel materials, identify flywheel fatigue life assessment methods, and develop the technology to detect the strength state of flywheels. The second challenge is the heat dissipation of the MW FES motor rotor under vacuum and magnetic levitation conditions. Thirdly, it is advisable to expand the FES application modes, build more flywheel array demonstration projects, test the short-term and high-frequency advantages of flywheel energy storage, and achieve the goals of usability, durability, and cost-effectiveness.

Prof. Dr. Xingjian Dai
Prof. Dr. Changsheng Zhu
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.