Tighter Grid Connection Rules for Low-Voltage BESS and Large-Scale Demand

The Ministry of Economy, Trade and Industry (METI) presented plans at an expert meeting to extend stricter grid connection rules to low-voltage grid-scale BESS facilities. METI has already introduced measures for generation facilities, including BESS facilities connected at high voltage or above. However, demand for connecting low-voltage BESS facilities has recently increased as operators seek to participate in the balancing market, which started allowing participation from low-voltage sources, including residential BESS and rooftop solar from April 2026. METI has received reports of hundreds of applications being submitted by a single company and determined that it must act quickly.

Grid connection applications for grid-scale BESS facilities continued to increase from around 600 in FY 2022 to 25,000 in FY 2025. To facilitate the early connection of projects with a high likelihood of proceeding, METI will also consider raising grid connection study fees. Key discussion points will include the conditions under which the fees would increase and the scale of the increases.

The meeting also approved details of measures to prevent grid capacity hoarding by large-scale customers with final contracted demand of 30 MW or more. The measures, which primarily target loads such as data centers, will apply when the start of power supply is delayed by more than one year from the original schedule or when actual demand remains below the contracted level for more than one year. METI plans to introduce the measures as early as April 2027 in areas with large numbers of grid connection applications. If a large-scale customer reduces its contracted demand from the original plan, the resulting unused grid capacity will be released to other customers.

🔍 Shulman Commentary:

METI is increasingly focused on ensuring that scarce grid capacity is allocated to projects with a high likelihood of proceeding, as connection applications continue to surge. Tighter requirements for BESS and measures against capacity hoarding by large-scale customers should help filter out speculative applications and release unused capacity. However, developers will face greater scrutiny and potentially higher costs when securing grid connections.

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