Diversified Japanese multinational company Asahi Kasei has started the construction of an alkaline water electrolysis pilot test plant for hydrogen production at its Kawasaki Works location in Kanagawa Prefecture in Japan. Construction and operation of the plant is supported by the Green Innovation Fund of Japan’s New Energy and Industrial Technology Development Organization. The groundbreaking ceremony was held at the end of October 2022. Start of operation is targeted in early 2024 following construction work, equipment installation and trial operation.For the sustainable large-scale production of hydrogen, it is essential for electrolysis equipment to be compatible with fluctuating electrical power input generated from renewable energy sources, like wind or solar power. To solve this issue, Asahi Kasei will introduce a pilot plant comprising several Aqualizer electrolyzer modules to perform various trial operations regarding responsiveness to power fluctuation and long-term durability in Kawasaki.The system features a changeable configuration with 1–4 water electrolysis modules of 0.8 MW. Utilizing multiple modules, the behavior of equipment under various conditions can be replicated, such as the case where one module malfunctions during operation, or the case of low output operation at night. This facilitates verification and improvement of apparatus design, operation methods and control technology.Furthermore, the Aqualizer electrolyzer is designed to replicate fluctuating output of renewable energy. Since renewable sources provide unstable power output, water electrolysis equipment needs to be highly responsive to fluctuations. As the equipment is designed to simulate such fluctuations, it enables verification of compatibility with renewable energy and coordination with the power system.