2022 12th International Conference on Renewable and Clean Energy (ICRCE 2022) is scheduled to be in Shiga, Japan during February 25-27, 2022, which is co-sponsored by Ritsumeikan University, Japan, and hosted in Biwako-Kusatsu Campus of Ritsumeikan University, Japan. But, due to the unspecified COVID-19 global pandemic and travel restrictions, the organizing committee has decided to host it as an all-virtual event via Zoom. The complete program is taken place on-line, including the keynote address and the regular conference talks.

We wish to express our thanks Prof. Lin Meng(Ritsumeikan University, Japan) to host this virtual conference, Prof. Saifur Rahman(Life Fellow of the IEEE and an IEEE Millennium Medal winner, Virginia Tech, USA) and Prof. Mingcong Deng (Tokyo University of Agriculture and Technology, Japan) gives warmly welcome to all participants by online.

Prof. Longya Xu (Life Fellow of IEEE), Prof. Ronghai Qu (Fellow of IEEE), Prof. Jinhua She (Fellow of IEEE), Prof. Masafumi Yamaguchi, Assoc. Prof. Akira Nishimura, and other distinguished scholars for sharing their deep insights on future challenges and trends in the conferences.

Moreover the conference was composed of 8 technical virtual oral sessions, topics coverd: Virtual Session 1: Materials and Battery Preparation; Virtual Session 2: Electrical Theory and Technology; Virtual Session 3: Generator Design and Optimization; Virtual Session 4: Electronics and Electrical Engineering; Virtual Session 5: Fault Diagnosis and Control System, Virtual Session 6: Smart Grid and Power System, Virtual Session 7: Clean Energy and Environment, Virtual Session 8: Energy Systems and Sustainability. Each parallel session went through smoothly and a “Best Presentation” award was issued at the end of sub-conference, with the support of session chairs.