Press Information

MHI to Introduce Large-capacity Lithium-ion Battery Energy Storage System
To Power Grid of Orkney Islands in UK, Jointly with SSE


Tokyo, November 22, 2012 - Mitsubishi Heavy Industries, Ltd. (MHI), jointly with SSE plc (formerly Scottish and Southern Energy plc), will begin an energy storage system demonstration project using the power grid in the UK's Orkney Islands, which has a high proportion of renewable energy generation in relation to demand. The project aims at demonstrating power supply stabilization in the region by introducing cargo container-type large capacity energy storage system using a lithium-ion rechargeable battery, which has a maximum power output capacity of 2MW (megawatts). The storage system is slated to be handed over for operational use in early 2013.

[Energy storage system under installation work]
The demonstration project will be conducted with the support of New Energy and Industrial Technology Development organization (NEDO) of Japan, under the programme of "Development of Technology for Safe, Low-cost, Large-size Battery System." In the project, Mitsubishi Power Systems Europe, Ltd. (MPSE), the business base for MHI's power system operations in Europe, and SSE Generation Ltd., the power generation unit of SSE group, will jointly provide the energy storage services to Scottish Hydro Electric Power Distribution plc (SHEPD), the SSE group company that handles power distribution in Scotland.

The energy storage system, which has the capacity to store approximately 800kWh (kilowatt hour) nominal, 500kWh normal usage, consists of two 40ft-long container units for the batteries and a 40ft-long container unit for the power conditioning system. Each battery container houses more than 2,000 units of lithium-ion rechargeable batteries. Power conditioning system container houses a system for conversion of direct current (DC)/alternating current (A/C) and the associated input/output controls.

The energy storage system will be installed at SHEPD's Kirkwall Power Station. In the cases of slight power shortage or power surplus, power is transmitted from/to the mainland through a submarine cable. When there is too much renewable energy, exceeding the export capacity of the cable to the mainland, the energy storage system will import some of the excess energy, reducing the need to constrain renewable generation at that time.

In July 2010, MHI agreed with SSE to collaborate in the development of low-carbon energy. The two companies have been studying a broad range of collaboration, including offshore wind turbine power generation system, carbon sequestration and storage (CCS) and high-efficiency power generation system. The energy storage demonstration project using rechargeable lithium-ion batteries is a part of that initiative. Going forward the two companies will further strengthen their collaborative relationship and intend to take a lead in the globally important drive to create a low-carbon society.

About MHI Group

Mitsubishi Heavy Industries (MHI) Group is one of the world’s leading industrial groups, spanning energy, smart infrastructure, industrial machinery, aerospace and defense. MHI Group combines cutting-edge technology with deep experience to deliver innovative, integrated solutions that help to realize a carbon neutral world, improve the quality of life and ensure a safer world. For more information, please visit or follow our insights and stories on