2026-03-31YUKU NEWS

[Grid-Scale Battery Business] Japan Energy Storage Development Organization's 2MW/5MWh Nanahongi Storage Station in Kamisato, Saitama Receives Power; Second Grid Connection in March Following Kaminara Storage Station

【系統用蓄電池事業】日本蓄電開発機構、埼玉県上里町で2MW・5MWhの七本木蓄電所が受電 3月中に2案件連続で系統接続（上奈良蓄電所）

On March 31, 2026, Japan Energy Storage Development Organization (JESDI) announced that its 2MW/5MWh Nanahongi Storage Station in Kamisato, Saitama completed power reception about three and a half months after construction began. It is JESDI's third domestic storage site and was energized just four days after the Kaminara Storage Station in Kumagaya. The facility is planned to serve the primary frequency control market.

  • 受電完了（energized）
  • 埼玉県児玉郡上里町
  • 2 MW
  • 5 MWh
  • 日本蓄電開発機構株式会社
  • イー・トップ株式会社
  • HOBE ENERGY株式会社
  • 株式会社RUTILEA

Full account

  • Announcement date: March 31, 2026, by 日本蓄電開発機構株式会社 (JESDI)
  • Project: Nanahongi Storage Station (七本木蓄電所), Kamisato-machi, Kodama-gun, Saitama Prefecture
  • Output 2MW, storage capacity 5MWh
  • Construction started December 15, 2025; power reception achieved in about 3.5 months
  • JESDI's third domestic storage station, after Aisho-cho (Shiga) and Kaminara Storage Station (Kumagaya, Saitama)
  • Kaminara Storage Station received power on March 27, 2026; Nanahongi followed just 4 days later, indicating a development structure able to advance multiple projects in parallel
  • Roles: JESDI as project owner overseeing overall development; E-Top Co., Ltd. (イー・トップ) as EPC contractor; HOBE ENERGY Co., Ltd. as battery system supplier; RUTILEA Co., Ltd. as aggregator and operations support provider (AI-based charge/discharge control, support for entry into the balancing market)
  • Equipment: HOBE ENERGY LFP (lithium iron phosphate) 5ft compact battery system, smaller than typical 20ft containers, easier to install where access routes are narrow or sites are constrained
  • Planned operation as primary control reserve (一次調整力) equipment for grid frequency maintenance
  • Article notes rising expectations for developers that can quickly handle land, design, construction, grid connection and market entry; sees this as accelerating storage infrastructure supporting renewables and balancing capacity
日本語で読む

【系統用蓄電池事業】日本蓄電開発機構、埼玉県上里町で2MW・5MWhの七本木蓄電所が受電 3月中に2案件連続で系統接続（上奈良蓄電所）

  • 2026年3月31日、日本蓄電開発機構株式会社（JESDI）が発表
  • 案件：七本木蓄電所（埼玉県児玉郡上里町）
  • 出力2MW、蓄電容量5MWh
  • 2025年12月15日着工、約3カ月半で受電
  • JESDIにとって滋賀県愛荘町、埼玉県熊谷市の上奈良蓄電所に続く国内3カ所目
  • 上奈良蓄電所は2026年3月27日に受電、本案件はわずか4日後の受電で、複数案件を並行推進できる開発体制を示す
  • 役割：日本蓄電開発機構が事業主体として開発全体を統括、イー・トップ株式会社がEPC、HOBE ENERGY株式会社が蓄電池システム供給、株式会社RUTILEAがアグリゲーター兼運用支援（AI活用の充放電制御、需給調整市場への参入支援）
  • 設備：HOBE ENERGY製LFP（リン酸鉄リチウムイオン）方式5ftコンパクト型蓄電システム。一般的な20ftコンテナ型より小型で、搬入経路が狭い場所や制約の多い用地でも設置しやすい
  • 電力系統の周波数維持に活用される一次調整力向け設備として運用予定
  • 用地確保から市場参入までを短期間で実現できる事業者への期待が高まっており、再エネ導入拡大や需給調整力確保を支える蓄電インフラ整備の加速につながるとみられる

Attached to: 上奈良蓄電所 →