In cooperation with TEPCO Power Grid, Inc., Hitachi has been conducting a demonstration project on its large-scale battery energy storage system on Izu Oshima Island south of Tokyo.

The island has an independent power grid and is a suitable testing site to assess the effect of introducing large amounts of energy from renewable sources on the grid. In the demonstration project, which is aiming toward the commercialization of the system, the durability of the battery energy storage system was an especially important concern.

Hitachi Chemical Company, Ltd., the developer of the lead batteries, has more than 10 years' experience in delivering devices to reduce power fluctuation. The company has been researching and analyzing batteries for longevity and has accumulated a knowledge base on the improvement of battery performance. In the Izu Oshima Island demonstration, Hitachi has also evaluating the durability and performance of the battery energy storage system through deterioration analysis utilizing data from Hitachi Chemical Company, Ltd. Further, Hitachi is creating control systems to monitor the operational status of the battery energy storage system for the demonstration project, not just for onsite monitoring but also for remote monitoring from the TEPCO's Oshima Power Plant at Izu Oshima Island in Tokyo and Hitachi's Omika Works in Ibaraki Prefecture. Hitachi is striving to develop control technology from research and analysis of the data for the operation of battery energy storage systems.

As Izu Oshima Island has been relying on diesel power generation, one of the purposes of this demonstration project is to evaluate the effect of using the battery energy storage system in reducing fuel costs. Hitachi is looking to find economical solutions to improve power grids in other island regions that have been relying on fossil fuels for their power supply. Hitachi is working towards optimal utilization of renewable energy and diesel power generation.

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