Japan Semiconductor Signs Virtual PPA for the Largest Floating Solar Power Plant in Western Japan
December 2, 2025
DIGITAL GRID Corporation
OTS LLC
Japan Semiconductor Corporation
Toshiba Electronic Devices & Storage Corporation
DIGITAL GRID Corporation ("Digital Grid"), acting as aggregator*1, OTS LLC ("OTS"), Kunishitaike Mega Float LLC ("Kunishitaike Mega Float", wholly owned by OTS), and Japan Semiconductor Corporation ("Japan Semiconductor"), a manufacturing group company of Toshiba Electronic Devices & Storage Corporation ("Toshiba Electronic Devices & Storage"), have entered into a Virtual Power Purchase Agreement (Virtual PPA)*2 for the supply of environmental value*3.
Under the agreement, OTS will supply Japan Semiconductor with environmental value derived from renewable energy generated by the Kunishitaike Solar Power Plant in Kagawa Prefecture, a newly commissioned floating solar power plant and the largest in Western Japan*4, with a total installed capacity of 7,842.1 kW. Through this agreement, Japan Semiconductor expects to reduce its annual greenhouse gas emissions by about 4,173 t per year*5 on a recurring basis, and the agreement will support the company in securing this target. Sourcing from a floating solar power plant, which install solar panels on water surfaces such as ponds and reservoirs, also offers benefits such as improved power generation efficiency through water cooling and the elimination of land development requirements.
This project was implemented through "RE Bridge®", an auction platform provided by Digital Grid that connects buyers and sellers of renewable energy, leading to the signing of a "GPA®"*6. Toshiba Electronic Devices & Storage recognizes climate change countermeasures as a crucial corporate responsibility and is promoting carbon neutrality at group sites by expanding the use of renewable energy, and this project is part of that effort.
Digital Grid’s mission is to “Empower the democratization of energy,” and it aims to pioneer a new future for the electricity industry. By providing platforms for electricity and environmental value trading, including renewable energy, Digital Grid enables customers to choose transactions according to their risk tolerance and decarbonization policies, supporting the early achievement of decarbonization goals and the realization of carbon neutrality by 2050.
OTS is a Japanese solutions company that develops high-voltage solar power plants and grid storage facilities nationwide, from land acquisition to construction, and that proposes self-consumption systems, O&M services, and power sales through PPAs. OTS will continue to promote GX (green transformation) toward securing carbon neutrality through construction of various kinds solar power plants and comprehensive proposals, including power trading.
Toshiba Electronic Devices & Storage Group operates semiconductor and storage products (HDD) businesses within Toshiba Group. Toshiba Electronic Devices & Storage Group has defined a carbon-neutral vision, and aims to reduce greenhouse gas emissions from its manufacturing sites by 100% by fiscal 2030*7. The company will combine the newly introduced virtual PPA with various other measures in place, and continue to pursue the best mix of renewable energy.
Details of the Floating Solar Power Plant Covered by This PPA
Plant Name: Kunishitaike Solar Power Plant
Location: Miki Town, Kida District, Kagawa Prefecture, Japan
Scheduled Start of Operation: December 2025
Installed Capacity: 7,842.1 kW (solar power plant equipment capacity)
Grid Connection Capacity: 6,000 kVA (special high-voltage equipment)
About Digital Grid
CEO: Yusuke toyoda
Established: October 2017
Capital: 1,139 million yen
Employees: 84 (as of September 2025)
Location: Akasaka Enokizaka Building 3F, 1-7-1 Akasaka, Minato-ku, Tokyo, Japan
Business: Operation of "DGP," an electricity and environmental value trading platform, provision of distributed power aggregation services
Website: https://www.digitalgrid.com/en/
About OTS
CEO: Tsutomu Domeki
Established: January 2015
Capital: 20 million yen
Employees: 41 (as of October 2025, group total)
Location: 3-15-12 Chiyoda, Naka-ku, Nagoya, Aichi Prefecture, Japan
Business: Construction of solar power facilities, grid storage facilities, O&M services, power sales
Website: https://www.ots-nagoya.com/ (Japanese only)
About Japan Semiconductor
President: Takeshi Sugahara
Established: April 2016 (through the merger of the former Iwate Toshiba Electronics and Toshiba Corporation’s former Oita Operations)
Capital: 15,000 million yen
Employees: Approx. 1,890 (as of September 2025)
Headquarters/Iwate Office: 6-6 Kitakogyo Danchi, Kitakami, Iwate Prefecture, Japan
Business: Development and manufacturing of MCU, ASIC, analog IC, linear image sensors, discrete semiconductors (power semiconductors)
Website: https://www.jsemicon.co.jp/eng/index.htm
About Toshiba Electronic Devices & Storage
CEO: Tomomi Ushijima
Established: July 2017
Capital: 10,000 million yen
Employees: Approx. 3,100 (as of March 2025)
Location: 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki, Kanagawa Prefecture, Japan
Business: Development, manufacture, and sales of semiconductor products (discrete semiconductors such as power semiconductors, small signal semiconductors, photocouplers; analog ICs, microcontrollers, automotive ICs) and storage products (high-capacity HDDs for data centers, portable hard drives, etc.)
Website: https://toshiba.semicon-storage.com/ap-en/top.html
*1 Aggregator: A business that bundles energy resources owned by consumers and stands between consumers and power companies to balance supply and demand and promote the use of consumer energy resources.
*2 Virtual PPA (Virtual Power Purchase Agreement): A contract in which companies and power producers trade only the environmental value (such as non-fossil certificates) of renewable energy, not the electricity itself.
*3 Environmental Value: The value of being environmentally friendly, such as renewable energy that does not emit CO₂. This value is traded via certificates and used for corporate decarbonization management.
*4 Largest floating solar power plant output in Western Japan as of December 2025, according to Toshiba Electronic Devices & Storage.
*5 Calculated based on Tohoku Electric Power's 2023 emission factor (residual) of 0.402 kg-CO₂/kWh.
*6 GPA®: "Green Purchase Agreement", a proprietary service name for direct trading of environmental value using the FIP system. Designed to stabilize the price of environmental value purchased by consumers.
*7 Includes the purchase of carbon credits.
* RE Bridge® and GPA® are trademarks of Digital Grid Co., Ltd.
* Other company names, product names, and service names may be trademarks of their respective companies.
* Information in this document, including product prices and specifications, content of services and contact information, is current on the date of the announcement but is subject to change without prior notice.