erex Co., Ltd.

Start of Commercial Operations for the First Grid-Scale BESS Project
2 MW Output / 8 MWh Storage Scale BESS Station Starts Operations in Kushima City, Miyazaki Prefecture
The First Step Toward Establishing a Revenue Model Spanning Multiple Power Markets
and Maximizing the Use of Renewable Energy

erex Co., Ltd. (Headquarters: Chuo Ward, Tokyo; Representative Director & President: Hitoshi Honna; hereinafter referred to as “the Company”) is pleased to announce that the “Miyazaki Prefecture Kushima City BESS Station” (hereinafter referred to as “the BESS Station”), the Company’s first grid-scale BESS project announced on September 4, 2025, started commercial operations on Tuesday, April 7, 2026.

This project marks the Company’s first grid-scale BESS business. Furthermore, amid increasing volatility in the electric power market, it is a critically important project for the Company aimed at creating earnings opportunities that span three markets; the supply/demand adjustment market, the capacity market, and JEPX (wholesale electric power market). The start of commercial operations represents a major milestone in building an earnings foundation for the BESS business.

１. Project Background
In Japan, while the adoption of renewable energy is progressing rapidly in line with the 7th　Basic Energy Plan,

• increasing output fluctuations of solar and wind power
• frequent control of renewable energy output due to grid constraints
• rising costs associated with maintaining the supply/demand balance

have become apparent.

Against this backdrop, grid-scale BESS is positioned as essential infrastructure that provides highly responsive “adjustment capability”, and as part of the government’s electricity system reform, the development and utilization of various markets, including the supply/demand adjustment market and the capacity market – are progressing.

The Company views these changes in market structure as mid/long term growth opportunities, has positioned the BESS business as a pillar for strengthening its competitiveness, and decided to invest in projects at an early stage.

２. Project Features and Significance of Start of Commercial Operations
The BESS Station is the first grid-scale BESS project, leveraging all the expertise the Company has cultivated in electric power retail, power generation, and aggregation. By connecting directly to the power grid, it provides rapid and flexible adjustment capabilities to address supply/demand gaps caused by fluctuations in renewable energy output.

Prior to the start of commercial operations, the Company conducted trial operations starting on Monday, March 16, 2026, and thoroughly verified the charging/discharging response performance, integration with the grid control system, and the operation of safety devices and protection functions. Through these verifications, the Company confirmed that the BESS Station meets the required performance and safety standards, and consequently transitioned to commercial operations on Tuesday, April 7, 2026.

Moving forward, the Company aims to establish an earnings structure that does not rely on any single market, such as the supply/demand adjustment market, wholesale electric power market, and capacity market, to optimize operations in response to market conditions, and to accumulate market-responsive expertise and maximize the market value of BESS. Furthermore, the Company will work to establish and expand the earnings base of the BESS business, contributing to the further promotion of renewable energy adoption and the strengthening of the overall power system.

■ Facility Overview

３. Future Schedule
Leveraging the operational track record and market response expertise gained from the BESS Station, the Company will

• expand its grid-scale BESS business
• create added value through integration with renewable energy
• contribute to the stabilization of the overall power system

The Company views BESS as “foundational infrastructure supporting a society powered primarily by renewable energy”, and is committed to realizing contribution to the sustainable enhancement of corporate value and de-carbonized society.

■ Overview of the Company’s Aggregation Business
Aggregation business is a business that optimizes the balance of supply and demand of electric power by integrally controlling and operating distributed power resources such as renewable energy, BESS, and demand-side resources, thereby creating and providing value in the electric power market.

The Company develops its aggregation business based on the following four pillars:

• Grid-scale BESS
• BESS integrated with renewable energy
• Corporate PPA
• Demand response

By combining these distributed resources, the Company aims to provide supply/demand adjustment capabilities and maximize earnings opportunities in the electric power market.

■ Contact
erex Co., Ltd. / IR&PR Department
TEL：+81-3-3243-1167
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.