Eco Changes

Power Demand ControlInitiative

Implementing Electricity Conservation Measures to Meet Japan's Need for Reduced Electricity Consumption

In 2011, Japan faced electricity supply shortages in the wake of the Great East Japan Earthquake. Electricity reduction targets were set by Tokyo Electric Power Co., Inc. and Tohoku Electric Power Co., Inc. for the summer and by Kansai Electric Power Co., Inc. and Kyushu Electric Power Co., Inc. for the winter, making 2011 a year in which all of Japan needed to reduce its electricity usage collectively. This special feature introduces Mitsubishi Electric's electricity conservation measures and results from fiscal 2012.

Overview of Mitsubishi Electric Group's Power Demand Control Initiative

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Ambitious Joint Targets Set by 18 Sites for the Summer

In July 2011, the Ministry of Economy, Trade and Industry (METI) issued an order to restrict electricity usage based on Article 27 of Japan's Electricity Business Act. This restriction required commercial-scale utility users with contract demand of 500 kW or more to reduce peak power demand by 15% over the previous year for the three-month period between July and September.

We employed a set of joint power restriction schemes to collectively control peak usage at 16 business sites in the Tokyo region and 2 business sites in the Tohoku region. We also set an ambitious target to achieve a 25% year-on-year reduction in peak power usage.

Conservation Efforts at Each Site

Each site, while adjusting demand targets, modified the way it used lighting and air conditioning and made changes to operating shifts. The Mitsubishi Electric Head Office, which is not a commercial-scale utility user, also curbed consumption.

Implementation of a Demand Control System

For central management of demand control, this system monitored power demand trends for each participating business site and alerted personnel when forecast demand approached the reduction target. This technology made it possible to avoid excessive power use.

Large-Scale Investments in Energy-Saving and Energy-Creating Facilities

Looking beyond the temporary period of power restrictions, Mitsubishi Electric installed 2 MW worth of photovoltaic (PV) systems to permanently enhance the Group's sustainability. Air conditioning equipment was replaced and lighting fixtures were upgraded with high-efficiency LED lights.

As a result, the 16 participating sites in the Tokyo region reduced peak power demand by 27.6% compared to the previous fiscal year. In terms of power consumption, they achieved a reduction of more than 2,670,000 kWh in August alone, or equivalent to 1,129 tons of CO2 (representing a 19% year-on-year reduction in emissions).

Effect from PV Systems

Peak demand occurs between the hours of 11:00 a.m. and 2:00 p.m. during the summer. Sites that installed PV systems were able to offset rises in power consumption by increasing power generation, effectively shifting the time of peak demand to later in the day and making it easier to adjust power usage.

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Applying Know-How Gained

Know-how gained in the summer was applied during the winter months to cut peak power demand by 14.9% within areas covered by Kansai Electric Power and 10.9% within areas covered by Kyushu Electric Power. We will build on this achievement by expanding the coverage of the demand control system to include all commercial-scale utility users within the Group (a total of 68 sites).

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Power Demand Control Initiative

Eco Changes: An Introduction

An overview of Eco Changes and how we're helping create a greener tomorrow.