Development Overview — 5 Phases
Battery storage development is broadly divided into 5 phases. Even for those with solar power development experience, batteries involve multiple issues not present in solar -- such as "bidirectional grid impact," "non-firm connection," and "noise countermeasures" -- making the development process different.
Phase 1: Site Screening → 1-3 months
Phase 2: Land Securing, Resident Communication, Regulatory Confirmation → 3-12 months
Phase 3: Grid Connection Review & Contract → 6-18 months
Phase 4: Design & Procurement (EPC Selection) → 3-6 months
Phase 5: Construction & Grid Interconnection → 12-48 months (depending on grid-side construction scale)
Phases 2 and 3 are often pursued in parallel, requiring a minimum of 2 years, typically 3-5 years for the entire process.
Phase 1: Site Screening
Checking Available Grid Capacity
Check the "projected power flow information" and "available capacity maps" published by each transmission and distribution operator, and determine whether there is availability in both reverse flow (discharge side) and forward flow (charge side) for candidate areas. Unlike solar, batteries require bidirectional availability.
Duration: 1-2 weeksListing Candidate Sites
The shorter the distance to the connection point (transmission tower or substation), the lower the access line construction costs. For high-voltage connections (utility pole), within 30-40m is ideal; for extra-high-voltage connections (66kV/154kV tower), within 500m is ideal. At distances over 1km, connection construction costs exceeding 100 million yen have been reported. Simultaneously, verify area (10,000 sqm or more for 50MW-class), road width (4m or more for large vehicle delivery), land classification, and regulatory restrictions.
Duration: 2-4 weeksPre-Checking Hazards & Regulations
Check flood, landslide, and tsunami inundation projection areas, cliff ordinances (red zones/yellow zones), agricultural promotion zones, and Forest Act applicability. This screening eliminates the majority of candidate sites.
Duration: 1-2 weeksPhase 2: Land Securing, Resident Communication, Regulatory Confirmation
Landowner Negotiations & Land Contracts
Advance consensus building with landowners and execute lease or purchase agreements (including provisional registration). Due to anti-reservation-hoarding measures enforced from January 2026, submission of land registry verification results, landowner negotiation status, and investigation results on land use regulations (Agricultural Land Act, Forest Act, etc.) are now required at the time of connection review application. However, at this stage, land use rights (ownership or lease agreement) are not yet required; submission of investigation results is sufficient. On the other hand, at the next step of "contract application," documents proving land use rights (ownership registration or lease agreement, etc.) must be submitted.
Duration: 1-6 monthsResident Communication & Consent
A key issue unique to batteries is noise. PCS operating noise reaches 45-60dB, battery cooling systems reach 50-65dB, and large-scale equipment can reach 65-100dB per container. In residential zoning districts, the nighttime standard is 45dB or below, making explanation to and consent from neighboring residents virtually mandatory. Nighttime noise standard values by zoning district are explained in Column 10.
Duration: 1-3 monthsRegulatory Permits — Confirmation & Acquisition
Obtain permits and approvals according to site characteristics, including agricultural land conversion permits, forest development permits, development permits (City Planning Act), buried cultural property surveys, and landscape ordinance compliance. If all are "not applicable," the process moves at maximum speed, but if agricultural land conversion is required, it can take over six months.
Duration: 1-6 monthsBoundary Determination & Surveying
Conduct boundary witnessing with adjacent landowners and boundary determination surveys. Practical procedures are involved, including obtaining powers of attorney and appointing sub-agents.
Duration: 1-3 monthsPhase 3: Grid Connection Review & Contract
Preliminary Consultation (Free)
Confirm approximate connection feasibility with the transmission and distribution operator. If capacity is clearly unavailable at this stage, change the candidate site.
Duration: 2-4 weeksConnection Review Application (Fee: ~200,000 yen/case)
Submit a formal connection review application. The review fee is 200,000 yen (excl. tax) per connection point for all transmission and distribution operators. From January 2026, submission of land investigation documents became required, and from April 2026, the security deposit for grid-scale batteries was raised to 10% of the estimated construction cost contribution (5% for other power sources). This was a temporary additional measure in response to the surge in battery connection review applications to approximately 9,500 cases in FY2024 (6x the previous year). The response period is 2 months from the acceptance date for high-voltage, inverter-based, and under-500kW cases, and 3 months for all others in principle, but extends further during periods of concentrated applications.
Duration: 3-6 monthsReceiving & Evaluating the Connection Review Response
The response document states connection feasibility, outline of required construction, estimated construction period, and construction cost contribution. This response document is the "value certificate" of battery development, and the primary basis for business continuation or withdrawal decisions. The response document is valid for 1 year from the date of response (Transmission and Distribution Business Guidelines, Article 89, Paragraph 1, Item 6).
Contract Application & Connection Charge Payment
Submit a contract application based on the connection review response and pay the construction cost contribution. At this stage, documents proving land use rights (ownership registration or lease agreement, etc.) must be submitted. If land use rights cannot be verified, the application is treated as withdrawn. Upon payment, grid interconnection rights are confirmed and the transmission and distribution operator begins construction.
Duration: 1-2 monthsPhases 4 & 5: Design, Procurement & Construction
In parallel with grid-side construction, proceed with battery, PCS, and extra-high-voltage transformer selection, EPC (engineering, procurement, construction) contract execution, grading work, and Fire Services Act notifications. Since the connection review evaluates capacity (kW), connection point, and grid impact, changing battery manufacturers after the connection review response is practically possible. However, if specifications are significantly changed from the original application, re-review may be required, and additional time and costs may arise.
Critical Differences from Solar Power
| Item | Solar Power | Grid-Scale Battery |
|---|---|---|
| Grid Impact | Reverse flow only | Reverse + forward flow (bidirectional) |
| Available Grid Capacity | Check reverse flow only | Bidirectional availability needed |
| Noise | Rarely an issue | PCS: 45-60dB, cooling system: 50-65dB. A source of resident disputes |
| Revenue Confirmation Timing | Confirmed with FIT/FIP certification | Depends on market prices (partially fixed with LDA win) |
| Equipment Flexibility | Panels and inverters are fixed at certification (changes may affect FIT price) | Manufacturer changes are practically possible after connection review response (major changes may require re-review) |
| Charging Cost | None (solar doesn't charge) | Electricity costs incurred during charging. Wheeling charges are not levied on charging energy (charged on storage losses and discharged energy) |
| Generator-Side Charges | Both kW charges + kWh charges | kW charges only (kWh charges are exempt) |
The Option of Acquiring Already-Developed Projects
Phases 1-3 above are the most upstream yet highest-risk stages of development. Land cannot be found, connection review results are negative, construction cost contributions are several times the estimate -- the way to avoid these sunk cost risks is "acquiring the rights to already-developed projects."
By acquiring projects with completed connection review responses and secured land, you can start your business from Phase 4 (design and procurement), shortening the development period by 1-3 years.
Compress Time to Commercialization with Pre-Developed Projects
We will send project summary materials for sites with completed connection reviews and secured land.
Contact Us →