Power Base is the largest storage battery module factory in Japan, located in Tamano City, Okayama Prefecture.
With secure and automated production, we manufacture and deliver storage batteries that are safe, reliable, and widely affordable.
All in effort to accelerate the adoption of renewable energy.

Our storage batteries are low in cost and achieve storage parity by using globally standard battery cells. They also comply with international safety standards to ensure the highest levels of safety, so we can continue to supply batteries from Tamano to the world.

Power Base is a clean, environmentally conscious factory that is built to exist as one with nature. It’s where gentle breezes blow in from the sea, and sunlight filters through the trees. Designed to have minimal impact on surrounding ecosystems and local communities, this is our vision for the future: Where society coexists with nature, thriving on clean and renewable energy.

The smooth architecture of the building gently curves up and down, connecting offices, meeting rooms, and research labs, while opening up its walls to reveal the outside environment. The elevated boardroom, which can be used by all, overlooks the beautiful sea and scattered islands of the Seto Inland Sea.

Construction Timeline

Summer 2023

Completion of Power Base manufacturing plant

Okayama Factory :
6-9-1 Tai, Tamano-shi, Okayama 706-0001
Tokushima Factory :
1524-3 Takakawahara Takakawahara, Ishii-machi, Meisei-gun, Tokushima


Completion of offices and lab facilities

Addition of offices, labs, cafeterias, and open spaces for new ways of working. Our goal is to create a place where people can work comfortably and feel one with the surrounding environment.

Power Base is conveniently located near Uno Port in Tamano City, a key port that connects the Setouchi islands to mainland Japan. We invite visitors to freely visit our open spaces and outdoor gardens to see firsthand the work that we do for a brighter future.


Kazuyo Sejima

Architect and founder of Kazuyo Sejima & Associates (est. 1987). In 1995, she co-founded the renowned architecture firm SANAA with Ryue Nishizawa, and served as General Director of the 12th International Architecture Exhibition at the Venice Biennale in 2010. She has won various awards and honors including a Architectural Institute of Japan Award*, Golden Lion* at the Venice Biennale International Architecture Exhibition, Pritzker Architecture Prize*, Officier de l’Ordre des Arts et des Letters, and the Medal with Purple Ribbon, among others. Major architectural works include the 21st Century Museum of Contemporary Art* (Kanazawa, Japan), Rolex Learning Center* (Lausanne, Switzerland), and Louvre Reims* (Reims, France).
*as SANAA.