Tamagawa Holdings' subsidiary, Tamagawa Energy, connected its grid-scale storage battery in Miyama City, Fukuoka Prefecture, to Kyushu Electric Power's network on July 1, ahead of the original July target the company had flagged when it agreed to buy the asset in May. The facility is small by utility standards but concrete: roughly 2 MW of output and 8 MWh of storage capacity, installed on a site where the battery equipment is already in place.
Tamagawa agreed to buy the station for about ¥684mn in self-funded cash under a contract signed May 25, with the board resolution on the same date. Formal transfer of ownership is still pending, expected in mid-August.
| Feature | Detail |
|---|---|
| Location | Miyama City, Fukuoka Prefecture (Kyushu Electric Power area) |
| Battery output | Approx. 2 MW |
| Battery capacity | Approx. 8 MWh |
| Acquisition price | Approx. ¥684mn, self-funded |
| Board resolution / contract signed | May 25, 2026 |
| Grid connection date | July 1, 2026 |
| Expected delivery date | Mid-August 2026 (planned) |
Once the handover closes, Tamagawa Energy plans to pursue the approvals needed to enter Japan's supply-demand adjustment market, the balancing-market mechanism operators use to sell frequency response and reserve capacity to the grid. The company says it is targeting an early start of commercial operation, though it has not disclosed a specific date for market entry.
Tamagawa Holdings frames the deal as an extension of a renewables portfolio built mostly from solar, small wind, geothermal and small hydro plants. The company says the financial effect of the acquisition is already built into its consolidated earnings forecast for the fiscal year ending October 2026, and it has committed to further disclosure if anything material changes before the handover completes.