Seven-Eleven Japan Realizes '100% Renewable Energy Ratio' at 10 Stores

With Kaneka's double-sided solar panel, Edison Power's storage battery system

2019/10/03 12:25
Kenji Kaneko, Nikkei BP Intelligence Group, CleanTech Labo & Sousuke Kudou, technical writer
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Solar panels installed on the roof of a Seven-Eleven store for the verification test (source: Kaneka)
The stationary storage battery system made by using used storage batteries at a Seven-Eleven store for the verification test (source: Edison Power)

Seven-Eleven Japan Co Ltd (Chiyoda-ku, Tokyo) started a verification test of operating 10 Seven-Eleven stores in Kanagawa Prefecture only with renewable energy Sept 26, 2019.

It is an effort based on the "Agreement on the Cooperation in the Promotion of SDGs," which the company concluded with the prefecture.

At the stores that participate in the verification test, Seven-Eleven Japan installed storage battery systems using solar panels manufactured by Kaneka Corp and used storage batteries of Nissan Motor Co Ltd's "Leaf" electric vehicle.

Moreover, by procuring power derived from "post-FIT" residential solar power generation (PV) systems, for which the FIT-based purchasing period ended, from Smart Tech (Mito City) and combining it with electricity generated by Seven-Eleven Japan, the company will achieve "100% renewable energy ratio" in effect.

The solar panel uses a hetero-junction technology and has a relatively high power generation efficiency. In addition, because it is a double-sided solar panel, it can increase the amount of electricity generated. At a standard Seven-Eleven store, 90 solar panels (total capacity: 28.8kW) can be installed.

The storage battery system uses Leaf's used batteries collected/procured by 4R Energy Corp (Yokohama City). And Edison Power Co Ltd (Kisarazu City, Chiba prefecture) manufactured it as a stationary storage battery system.

The capacity of the storage battery system is 40kWh per unit. In case of power outage, etc, it can power refrigerators in a store. The batteries were recycled at a factory that obtained a certification based on the "UL1974" evaluation standard concerning recycling of batteries.

According to Edison Power, it developed a dedicated rack so that the battery system can be installed in small spaces in convenience stores. Also, the company established a system to control the entire system (e.g charge/discharge of used storage batteries and charge using solar electricity).

According to Seven-Eleven Japan, the amount of CO2 emitted through its business activities is accounted for roughly by "store operation" and "physical distribution," and the former accounts for about 90%. So, with the latest effort, a large amount of CO2 is expected to be reduced, it said.