Katsushika-ku, Tokyo-Kanamachi Water Purification Plant-Energy Reforms (around 2000), when the metropolitan infrastructure reached a turning point

Katsushika-ku, Tokyo-Kanamachi Water Purification Plant-Energy Reforms (around 2000), when the metropolitan infrastructure reached a turning point
Around the year 2000, Japan's energy policy was undergoing a clear transition from a centralized to a decentralized approach, and the introduction of cogeneration, in which municipalities and businesses generate their own electricity, became a realistic option against the backdrop of partial electricity deregulation following the 1995 revision of the Electricity Business Act. Increasing demand for electricity, concerns about energy security, and the growing demand for energy conservation and global warming countermeasures since the adoption of the Kyoto Protocol in 1997 were driving this trend. Particularly in large cities, improving the cost of electricity and operational efficiency of public infrastructure was an urgent issue.

The Kanamachi Water Treatment Plant in Katsushika Ward, Tokyo, is the second largest water treatment plant in Tokyo, with a huge water treatment capacity of up to 800,000 tons per day. This capacity also means that the plant consumes an extremely large amount of electricity, all of which was previously purchased from the Tokyo Electric Power Company (TEPCO), creating structural issues in terms of both operating costs and energy efficiency.

In response to this situation, the Ishikawajima-Harima Heavy Industries, Shimizu Corporation, and Denryoku Kaihatsu Group introduced a high-efficiency cogeneration system. The system, which recovers waste heat and reuses it as hot water and steam at the same time as generating electricity, is compatible with the water purification process and enables rational energy operation suitable for urban infrastructure.

This case is highly evaluated not only for its energy conservation, but also as a pioneering attempt to incorporate distributed power sources into critical infrastructures. From the perspective of dispersing risk in the event of a disaster and improving the independence of urban functions, this case symbolizes the energy transition that took place around the year 2000.