We will strengthen our power storage business as a pillar of our energy business after solar cells, consumer rechargeable batteries and vehicle rechargeable batteries.

Panasonic expects the global storage market to reach about 2 trillion yen in fiscal 2020.

Our sales in fiscal 2011 were about 10 to 20 billion yen, and we aim to increase that to 50 billion yen first in fiscal 2015.

The power storage business is expected to have a technology that can easily use batteries in addition to market growth.

The large battery storage system we supply includes 312 battery storage modules equipped with 18650 cylindrical lithium ion rechargeable battery units, as well as battery control units that control the linkage of the system and charge and discharge. When properly combined, it can support a variety of sizes (Figure C-1).

Figure C-1: Power storage module control technology plays a central role

Large battery storage systems use battery storage modules that array cylindrical lithium-ion rechargeable batteries.

Technology to control charging and discharging of a large number of storage modules and linkage with the system will contribute to product differentiation.

The 1.5MWh storage system (commonly known as "megawatt battery") introduced by the vehicle-mounted battery factory "Jiaxi Green Energy Park" uses about 1,000 storage modules.

The battery control unit group, designed to enable multiple modules to operate in tandem, can manage the charging and discharging of each battery while observing the actions of more than 300,000 batteries.

Thus, the entire battery can be used as a virtual large battery.

The performance of the built-in lithium-ion rechargeable battery is also important, but we have an advantage in control technology.

We have filed 71 patents on battery control for storage systems in Japan alone.

Currently, we use our own lithium-ion rechargeable batteries. Of course, sourcing from outside should also be an option.

However, it is also true that close information exchange with the rechargeable battery business unit contributed to the accumulation of battery control technology.

In the second half of 2013, a battery storage system using on-board lithium-ion rechargeable batteries is planned for production.

Battery control technology will also have to change.

With the continuous progress of batteries, we have advantages in battery business which can be applied to storage system business.