erex Co., Ltd.

Announcement Regarding an Agreement with SAMSUNG C&T JAPAN on Joint
Development of Grid-scale Battery Energy Storage System Business and Others in Japan

erex Co., Ltd. (Head office: Chuo-ward, Tokyo; Representative Director & President: Hitoshi Honna; hereinafter referred to as “the Company”) is pleased to announce that on October 31, 2025, the Company signed a memorandum of understanding with SAMSUNG C&T JAPAN CORPORATION (Head office: Minato-ward, Tokyo; Representative Director: Wonseok Jung; hereinafter referred to as “SCTJ”) regarding an agreement on joint development of grid-scale battery energy storage system (BESS) business and others in Japan (hereinafter referred to as the “Joint Development”).

The two companies will carry out the Joint Development through a joint venture, aiming to develop grid-scale BESS projects on a nationwide scale. The two companies are also preparing to jointly invest in a 2MW/8MWh storage battery plant in Kushima City, Miyazaki Prefecture, which was announced by the Company on September 4, 2025.

1. Background and purpose of signing the memorandum of understanding
With Japan’s 7th Strategic Energy Plan setting a goal to expand the introduction of renewable energy, securing supply-demand adjustment capability in Japan’s power grid has become an urgent issue. In particular, the introduction of large-scale BESS is considered essential to cope with output fluctuations in variable renewable energy sources such as solar and wind power generation, and to maintain grid stability. According to estimates by the Agency for Natural Resources and Energy, the introduction of storage battery on a scale of 14.1 to 24.8 GWh is projected by 2030, and the market for grid-scale BESS is expected to grow rapidly in the future.

The Company has extensive experience in power trading and power generation businesses, as well as in handling various permits and licenses in Japan. The Company has strengths in building systems that cover everything from project development to O&M (operation and maintenance). SCTJ, on the other hand, has strengths in procurement capabilities and financial scheme developments.

The two companies, by combining the strengths of both companies in this way, will build a highly competitive business model for grid-scale BESS and contribute to strengthening Japan’s energy infrastructure.

2. Future outlook
The two companies will establish a working group to consider development targets and other matters for 2026. The two companies also plan to work on large-scale projects exceeding 20MW in this context.

Furthermore, in the Joint Development, the Company anticipates receiving orders for aggregation services for grid-scale BESS (including planning services related to operation such as charging and discharging, and various market responses).

In this way, the two companies will contribute to the expansion and adoption of renewable energy in Japan by promoting the Joint Development.

■  Contact
erex Co., Ltd. / IR&PR Department
TEL：+81-3-3243-1167　　FAX：+81-3-3243-1184
E-mail：ir.info@erex.co.jp

Note:
This document is an English translation of the original Japanese language document and has been prepared solely for reference purposes. No warranties or assurances are given regarding the accuracy or completeness of this English translation. In the event of any discrepancy between this English translation and the original Japanese language document, the original Japanese language document shall prevail in all respects.