Over two days, Swiss and Japanese experts explored how energy systems can respond to rising electricity demand while becoming more resilient, flexible, and sustainable. From renewable energy and hydrogen to advanced storage, smart grids, and AI, the discussions highlighted both the technological opportunities and the difficult choices shaping the energy transition.
Energy security emerged as a central concern for both Switzerland and Japan. While the two countries face different energy realities, both must navigate growing electricity demand, dependence on energy imports, decarbonization, and the need for reliable infrastructure.
Dr. Kazunari Sasaki from Kyushu University highlighted the importance of considering these issues together, arguing that “without the discussion of nuclear, we cannot consider the future energy and also energy security and also carbon neutrality.” In addition, he outlined Japan’s long-term approach to hydrogen, including the role of policy, infrastructure, and research in building a hydrogen economy.
For Prof. Ryoichi Komiyama, Hitachi-University Tokyo Lab, the challenge is to balance three objectives: sustainability, affordability, and stability. His energy-system modelling examines thousands of combinations of technologies and scenarios, illustrating the trade-offs involved in different pathways, from high shares of renewables to nuclear power and hydrogen imports.
Dr. Toshihiro Tanaka from the University of Osaka similarly stressed that “the carbon neutrality challenges are deeply interconnected” and cannot be addressed by a single technology or field. His work on digital twins and urban energy systems explores how mobility, buildings, energy demand, and electricity networks can be better coordinated as cities become increasingly electrified.
As renewable generation expands and electricity demand becomes more variable, the ability to balance the system is becoming increasingly important. Thomas Reinthaler from Swissgrid summed up the infrastructure challenge with a simple message: “No transition without transmission.”
But stronger grids are only part of the equation. Reinthaler described flexibility as “the steering wheel” of the energy system, while emphasizing the need for much better and more accurate real-time data and forecasting. Batteries, electric vehicles, demand response, and other flexible resources can all help manage fluctuations in renewable generation and demand.
"Energy is critical infrastructure for Switzerland, as it is for any country in the world. It supports our economies, so it’s important that we have a secure, robust, and sustainable energy supply. Building relationships takes time, and we want to continue our efforts to strengthen the links with our Japanese colleagues."
Dr. Yasmine Calisesi Executive Director, EPFL Energy Center"Switzerland and Japan face very similar challenges. We depend on energy imports, and we want to decarbonize. Working together will really help us move forward on this path and find solutions to decarbonize our energy systems."
Dr. Christian Schaffner Executive Director, Energy Science Center ETH Zurich“Japan and Switzerland are actually facing the same challenge: how do we achieve carbon neutrality by 2050? It’s important to learn from each other—how we tackle this challenge and how we find solutions. By co-organizing this event, we’re not only building new networks, but also sharing ideas and, hopefully, getting closer to solutions faster.”
Prof. Matthias Sulzer Member of the Directorate, EmpaThe discussions also highlighted that there is no single technological answer to the energy transition. Hydrogen and other energy carriers will be important for sectors that are difficult to electrify directly, while nuclear power, renewables, storage, and grid infrastructure each have different roles to play.
Marius Schwarz from Axpo examined the challenge of meeting Switzerland’s future electricity needs, particularly during winter, while Komiyama’s scenarios illustrated the choices and trade-offs involved in Japan’s future energy mix. The panel discussion further explored the economic consequences of grid instability and the importance of flexibility.
Bringing Swiss and Japanese perspectives into the same conversation offered an opportunity to compare different approaches to shared challenges and identify where collaboration can help build more resilient, flexible, and secure energy systems.
The second edition of the Swiss-Japan Energy Days took place at Swissnex in Japan on September 25 and 26, during Expo 2025 Osaka. Against the backdrop of the world’s Expo theme “Designing Future Society for Our Lives,” the conference convened leading experts, researchers, policymakers, and startups from Switzerland and Japan to address the urgent global energy and climate challenges of our time.
The Swiss-Japan Energy Days 2024, a groundbreaking event, was held on September 10 and 11 across two venues—ETH Zürich and Swissnex in Japan. The conference brought together top-tier academic, policy, and industry experts, as well as breakthrough startups from Switzerland and Japan to tackle the pressing challenges of the global energy and climate crisis.
On September 10 and 11, 2024, the first edition of the Swiss-Japan Energy Days will be held simultaneously at ETH Zürich and Swissnex in Japan. This conference aims to discuss the challenges facing the Swiss and Japanese energy sectors in the current combined energy and climate crisis.
