We have been organizing cross-division symposia for over a decade, focusing on energy storage and conversion devices primarily based on electrochemical reactions. Throughout this period, numerous presentations and discussions have been held on key topics such as local production and consumption of energy, integration with renewable energy, comprehensive science from materials to systems, process development, the integration of measurement and simulation, and the use of data-driven approaches. In this symposium, in addition to general presentations, we aim to share and discuss the current background, technologies, challenges, and future perspectives related to these ongoing efforts.