Mitsubishi Heavy Industries, Ltd., (MHI) has delivered a large-capacity energy storage system employing lithium-ion rechargeable batteries to the Shimizu Institute of Technology in Tokyo. The institute, a technology arm of Shimizu Corporation, a major Japanese construction firm, is presently conducting advanced studies, including verification testing, into various technological areas, including microgrids, which are a localized power management system, and smart BEMS (building and energy management system). The energy storage system, which is capable of 100 kilowatt (kW) output and storage of 60 kilowatt hours (kWh), is one of today's largest indoor lithium-ion battery-based systems in Japan. Going forward MHI and Shimizu will jointly conduct tests using the energy storage system and verification of the microgrid system, in a quest to respond to increasing social needs for stationary energy storage systems.
The microgrid installed at the Shimizu Institute of Technology has a total output of 600 kW. It consists of multiple power sources, including a photovoltaic generation system, and an energy storage system, all configured for integrated control.
The lithium-ion rechargeable battery energy storage system installed in the microgrid system uses 320 units of a 50 Ah (ampere hour) class cell. Compared with storage systems using other battery types, such as lead-acid and nickel-hydride batteries, the system adopting lithium-ion battery, which has two to three times higher energy density, offers greater compactness plus the capability to supply higher power output in a short time. The energy storage system consists of batteries and their racks, a direct current/alternating current (DC/AC) convertor, and a system control device.
MHI has been marketing the lithium-ion rechargeable battery energy storage system for multi-unit apartment buildings. The company has also completed the development of Japan's first container-type megawatt-class energy storage system, using more than 2,000 units of lithium-ion cell. The company has already begun marketing the system for a variety of applications: as a peak-cut system to accommodate peak electric demand, as an auxiliary power source to achieve stable power supply in unstable power grid areas, and as a power grid stabilization system to promote renewable energy such as wind power and solar energy.
In the verification testing to be conducted by Shimizu, MHI will jointly accumulate storage system management data toward achieving environmental and economic benefits. MHI will further utilize the knowledge obtained through this initiative both in the creation of a market for its batteries leveraging the company's system development capability, and in the establishment of advanced technology to enable the company's full-fledged entry into the "smart community" market, which is focused on energy-saving, environmentally conscious low-carbon cities.
As a comprehensive manufacturer in both the energy and machinery fields, going forward MHI will further strengthen its development activities in energy storage technologies and products as its way of contributing to the establishment of an energy-saving, less environmentally burdened society.