Japan Energy Storage Development Institute Opens 'Kami-Nara Battery Storage Plant' in Kumagaya, Saitama ― Enters Supply-Demand Adjustment Market Just 2.5 Months Post-Energization Using HOBE ENERGY's Integrated System

Japan Energy Storage Development Institute Co., Ltd. (Headquarters: Tokyo; Representative Director: Akira Hoshino; hereinafter "JESDI") announces the commencement of operations today, June 16, 2026, at the grid-scale battery storage project "Kami-Nara Battery Storage Plant," which it has been developing in Kumagaya City, Saitama Prefecture.

The Kami-Nara Battery Storage Plant adopted HOBE ENERGY Co., Ltd.'s integrated storage system (fully integrated design of battery, EMS, PCS, and power receiving/transformation equipment), demonstrating a remarkable achievement: commissioning completed in just 4 days and supply-demand adjustment market entry testing finalized in 1 day. Following the previous announcement of "continuous energization by March and adoption of the 5ft compact model," this release highlights the project's rapid implementation capability in completing connection adjustments, integrated testing, and market entry preparations within a short timeframe after energization.

Market Trends

The Japanese government, in the 7th Strategic Energy Plan (approved by cabinet decision in February 2025), has set a target of achieving a 40–50% renewable energy ratio by fiscal year 2040. Grid-scale battery storage systems are positioned as critical infrastructure supporting the expansion of renewable energy. The supply-demand adjustment market (primary regulation capacity), managed and supervised by the Organization for Cross-regional Coordination of Transmission Operators (OCCTO), is a highly public-interest market. It provides a well-established institutional framework enabling long-term revenue participation.

According to a survey by Yano Research Institute, the domestic grid-scale battery storage business market is projected to grow approximately tenfold—from 45 billion yen in FY2024 to 424 billion yen in FY2030 (announced January 2026)—indicating sustained market growth.

Installation Overview

Storage Plant Name: Kami-Nara Battery Storage Plant

Location: Kami-Nara, Kumagaya City, Saitama Prefecture

Output: 2MW

Construction Start Date: December 1, 2025

Energization Date: March 27, 2026 (approximately 4 months after construction start)

Operation Start Date: June 16, 2026 (approximately 2.5 months after energization, 6.5 months after construction start)

Construction Partner: E-Top Co., Ltd.

Operations Support: RUTILEA Inc.

Storage System: HOBE ENERGY Co., Ltd.'s 5ft compact integrated storage system (fully integrated design of EMS, PCS, and power receiving/transformation equipment)

HOBE ENERGY's Integrated System

Typically, grid-scale battery storage plants procure batteries, EMS, PCS, and power receiving/transformation equipment from different manufacturers, requiring significant engineering effort for specification alignment and integrated testing. At the Kami-Nara Battery Storage Plant, HOBE ENERGY Co., Ltd. provided all equipment through an integrated design and single-supplier model. This project marks one of the first domestic grid-scale storage facilities to achieve commercial operation using this model, demonstrating the company's technical capabilities and responsiveness.

Battery System: 5ft compact LFP battery – HOBE ENERGY

EMS: In-house energy management system (charge/discharge control, optimization) – HOBE ENERGY

PCS: Power conditioner (DC/AC conversion) – HOBE ENERGY

Power Receiving/Transformation Equipment: PCS and step-up transformer integrated power receiving/transformation container – HOBE ENERGY

Integration & Commissioning: Inter-device connection adjustment, integrated testing, and site-specific specification optimization – HOBE ENERGY

Additionally, the adoption of the 5ft compact model—easier to transport and install compared to the industry-standard 20ft container—enables deployment even in locations with narrow access routes or sharp curves. The combination of physical installation ease and fully integrated equipment management enables rapid on-site commissioning.

Market Entry Just 2.5 Months After Energization

Thanks to HOBE ENERGY's fully integrated system design, the Kami-Nara Battery Storage Plant drastically shortened its post-energization startup timeline. It successfully entered the supply-demand adjustment market just 2.5 months after energization (March 27, 2026). The three key factors behind this achievement are outlined below.

Three Factors Enabling Market Entry Within 2.5 Months

① Commissioning completed in just 4 days. Since HOBE ENERGY integrated the design of the battery, EMS, PCS, and power receiving/transformation equipment, inter-device specification alignment was finalized during the design phase, minimizing on-site commissioning time.

② Market entry testing completed in 1 day through HOBE–RUTILEA collaboration. The equipment provider (HOBE ENERGY) and market operator (RUTILEA) shared requirements as a unified team from the early design stage, eliminating the need for individual pre-test adjustments.

③ Efficient TSO coordination. Interconnection and market entry discussions with transmission system operators (TSOs) were conducted accurately by a team well-versed in entry requirements, minimizing procedural delays.

The achievements of "4-day commissioning and 1-day testing" at the Kami-Nara Battery Storage Plant validate the reproducibility of HOBE ENERGY's integrated system and directly contribute to accelerating the deployment speed of follow-up projects such as the Nanahonmatsu Battery Storage Plant.

Future Outlook

The achievements at the Kami-Nara Battery Storage Plant—"4-day commissioning and 1-day testing"—demonstrate the replicability of JESDI's storage plant deployment model. The simultaneous operation launch with the Nanahonmatsu Battery Storage Plant (in Kamisato Town, Saitama) is a direct result of this framework. JESDI is already advancing multiple upcoming projects—including the Hachigata and Orinokuchi Battery Storage Plants—using this proven model.

JESDI will continue strengthening its four-party integrated framework with HOBE ENERGY Co., Ltd. (integrated storage system), RUTILEA Inc. (aggregator and market operations), and E-Top Co., Ltd. (construction), accelerating the nationwide deployment of battery storage infrastructure.

Inquiries

Japan Energy Storage Development Institute Co., Ltd. Inquiry Form: https://japan-energystorage.co.jp/contact/

Company Overview

Company Name: Japan Energy Storage Development Institute Co., Ltd. Established: October 2024 Representative Director: Akira Hoshino Headquarters: 2-12-4-303 Kita-Aoyama, Minato-ku, Tokyo 107-0061 Capital: 10 million yen TEL: 03-6899-2733 Business: Design, construction, operation, maintenance, management, technology development, sales, and power supply related to battery storage plants URL: https://japan-energystorage.co.jp

Partner Companies

HOBE ENERGY Co., Ltd. https://hobeenergy.co.jp/ RUTILEA Inc. https://www.rutilea.com/ E-Top Co., Ltd. https://etop-co.com/