2026-10-14日経クロステック（xTECH）

Asking Toshiba, a veteran aggregator, about the future of grid-scale battery storage (page 2)

アグリゲーター老舗・東芝に聞く、系統用蓄電池の将来（2ページ目）

In this interview page, Toshiba says it has aggregation contracts with about 120 grid-scale battery sites, expected to reach about 200 by fiscal year-end, mainly high-voltage sites but increasingly extra-high-voltage ones. It explains its revenue-sharing model, says battery revenue in Japan currently relies almost entirely on the balancing market, and expects wholesale arbitrage to grow in importance, though institutional reform may be needed.

  • planned
  • 長野県下高井郡
  • 東芝
  • 合同会社OPTIRON北信

Full account

  • Toshiba has contracted with about 120 grid-scale battery sites; expected to rise to about 200 by the end of this fiscal year.
  • Mainly high-voltage (高圧) storage sites, which are quick from development to operation; contracts with large extra-high-voltage (特高) sites have also begun.
  • Contract model: aggregation contract with the storage owner, revenue shared; Toshiba does not own equipment; role resembles outsourced operations (daily operation and trading after commissioning).
  • Offtake contracts (guaranteed fixed revenue to owner for a set period, aggregator keeps upside) are offered by major energy companies; Toshiba considered but has not adopted them due to high risk.
  • Image caption: Toshiba won the aggregator contract from 合同会社OPTIRON北信 for the 木島平蓄電所 (長野県下高井郡), scheduled to start operation in FY2028.
  • Three revenue sources: wholesale arbitrage, balancing market (需給調整市場), capacity market. In practice currently a "one-legged" reliance on the balancing market, which is more profitable than wholesale arbitrage.
  • In Europe, the US and Australia, revenue has shifted from balancing to wholesale markets; balancing markets saturate as batteries increase, so Japan's balancing profitability will fall and wholesale will matter more.
  • Europe has negative prices widening spreads; Japan lacks such a system, so institutional reform may be needed for sufficient arbitrage revenue.
  • Despite regulatory uncertainty, Japan is currently a "profitable market" globally; Toshiba's research on Texas shows Japan can sometimes be more profitable.
  • Next page: in-house algorithm development.
日本語で読む

アグリゲーター老舗・東芝に聞く、系統用蓄電池の将来（2ページ目）

  • 東芝はこれまでに約120件の系統用蓄電池サイトと契約、今年度末までに200件ぐらいに増える見込み。
  • 開発から稼働までが早い高圧蓄電所が主体だが、大規模な特高蓄電所との契約も始まっている。
  • 契約形態：蓄電所所有事業者とアグリゲーション契約を結び収益をシェア。東芝は設備を所有せず、稼働後の日々の運用・トレーディングを担う業務代行に近い。
  • 一定期間・一定収益を保証し上振れ分をアグリゲーターが得るオフテイク契約は大手エネルギー会社などが提供。東芝も検討したがリスクが大きく現時点で不採用。
  • 画像説明：東芝が合同会社OPTIRON北信からアグリゲーターを受注した「木島平蓄電所」（長野県下高井郡）、2028年度運開予定。
  • 収益源は卸市場の裁定取引、需給調整市場、容量市場の3つとされるが、現状は需給調整市場の一本足打法。収益性で需給調整市場が選ばれる。
  • 欧米・オーストラリアでは収益源が需給調整市場から卸電力市場へ移行。需給調整市場は蓄電池増加で飽和し、日本でもいずれ収益性が下がり卸市場の重要性が高まる。
  • 欧州はネガティブプライスで卸市場スプレッドが大きいが、日本はそうした制度がなく、十分な収益には制度改革が必要かもしれない。
  • 制度面の不透明性はあるが、現時点で世界的にも「儲かる市場」。テキサス州と比較して日本の方が収益性が高いこともある。
  • 次ページ：アルゴリズムを自社開発。

Attached to: 木島平蓄電所 →