Kansai Transmission and Distribution found errors, primarily available capacity understatements, in 5,573 of 14,942 responses to preliminary grid connection consultations conducted between March 2020 and February 2025, the company said on March 31, 2025.
According to the Kansai Electric Power Group’s transmission and distribution unit, the most common error, present in over 80% (4,560) of the affected cases, was saying there was no available capacity without grid upgrades to handle reverse power flow even when such upgrades have been done already. In 354 cases, including 90 overlapping, the company stated available capacity was restricted to 500kW due to thermal constraints even though there was no such restriction.
In 749 separate cases, Kansai Transmission and Distribution said reverse power flow would not occur even though it actually would.
“As soon as we discovered the errors, we retrained the relevant departments and confirmed that correct answers are being provided now,” said the statement. The company also said it is in the process of contacting the affected businesses.
Kansai Transmission and Distribution is Japan’s third grid operator to admit mistakes in a significant portion of preliminary grid connection consultation responses and the first one to provide a detailed breakdown.
Its internal audit was likely triggered by TEPCO Power Grid’s February 2025 announcement that it found incorrect information in 61% of the 31,313 September 2019 to December 2024 responses after one of the affected businesses inquired about the information it received. About a month later, Kyushu Electric Power Transmission and Distribution said it also found incorrect information in 2,113 of 18,779 responses given between April 2020 and January 2025.
With all three companies having found recurring instances of similar errors, it is likely that similar disclosures from Japan’s remaining grid operators will follow.
The preliminary consultation is an optional step in the grid connection application process. However, it is a key part of the development process as it provides developers with an idea of how difficult it will be to get their project online. Because of that, the errors may have led to delays or cancellation of some projects.
