Japan Solar Update: No.202 (May 25 ~ 29, 2026)
Before the operation of the upper limit setting begins, there is a possibility that there will be a rush to apply for connection consideration.
<Key points>
- Regarding grid-scale storage batteries, the upper limit of the number of connection assessments per operator will be applied from August 1, 2026, and if the applications have been accepted as of July 31, 2026, the response will be as before
- If the number of applications exceeds the upper limit, the general power transmission and distribution operators will not check the application documents, and after the upper limit is resolved, the grid connection applicants will be asked to apply again for connection assessment
- The specific upper limit is being calculated, but the results of the calculation of the upper limit in each area were presented as a reference
Response to rapid grid connection of power generation facilities including grid storage batteries
-
- Relevant regulations of the OCCTO will be revised, which will be applied from August 1, 2026
- If the number of applications exceeds the upper limit as of July 31, 2026, the response will be the same as before
- The upper limit will be applied to projects that were applied before August 1 but have not been accepted as of August 1
- The specific upper limit is being calculated by general transmission and distribution companies, and will be published on each operator’s website as soon as the calculation is completed
Handling of applications exceeding the upper limit
If the applications exceeds the upper limit, the general transmission and distribution company will not check the application documents, and after the upper limit is resolved, the applicants will be asked to apply again for connection assessment
Estimates of the upper limit (reference)
Set the upper limit to the average value +2σ or the lowest value of 5 cases, whichever is higher
| Area | Actual Fiscal Year of Use | Average+2σ* | Upper Limit* | ||||
|---|---|---|---|---|---|---|---|
| Hokkaido | FY 2023 | 4 | 5 | ||||
| Tohoku | FY 2023 | 6 | 6 | ||||
| Tokyo | FY 2023 | 11 | 11 | ||||
| Chubu | FY 2023 | 4 | 5 | ||||
| Hokuriku | FY 2023 | 8 | 8 | ||||
| Kansai | FY 2023 | 10 | 10 | ||||
| Chugoku | FY 2023 | 4 | 5 | ||||
| Shikoku | FY 2023 | 4 | 5 | ||||
| Kyushu | FY 2023 | 8 | 8 | ||||
| Okinawa | – | – | – | ||||
* Based on estimates as of March 2026 and may differ from the actual upper limits to be applied
Figure 1 Summary of deliberations related to setting of the upper limit of the number of connection assessments per operator
Source: Materials of the 10th meeting of the Working Group on the Next-Generation Electric Grid, complied by RTS Corporation