COLUMN 06 — Rights Transfer in Practice
Equipment Changes After Grid Connection Review
— What Changes and What Stays the Same
One of the most common concerns when acquiring development rights is "Can I change the battery or PCS listed in the connection review response to a different manufacturer?" The short answer is: in most cases, yes. However, you need to properly understand the types and conditions of procedures.
Equipment in the Review Response is a "Precondition," Not a "Specification"
When applying for a connection review, you must specify the planned battery (BSS) and power conditioner (PCS) manufacturer, model, and specifications. The transmission and distribution operator reviews the grid impact based on this information and responds with connection conditions and construction charges.
The important point here is that the equipment specifications in the review response are preconditions at the time of review, not an obligation to use that equipment. After acquiring the rights, it is institutionally possible to adopt a different manufacturer's battery or PCS.
Core Point: What the connection review response confirms is "grid-side conditions"
What the connection review response confirms is: the connection point (which substation/tower to connect to), the interconnection voltage (66kV, 154kV, etc.), the estimated construction charges, and the required grid-side reinforcement works.
These are grid-side conditions, fundamentally different from customer-side (battery operator-side) equipment specifications. In other words, operator-side equipment can be changed as long as grid-side conditions remain unchanged.
Three Procedures for Equipment Changes — "Not Required," "Confirmation," and "Re-Review"
Equipment change procedures are divided into three levels depending on the nature of the change.
| Type of Change | Procedure | Duration | Cost |
|---|
| Changes with no grid impact (equivalent spec equipment swap) | No procedure required (handled via technical requirements confirmation) | — | None |
| Changes with unclear grid impact (manufacturer change, PCS spec change, etc.) | Connection review necessity confirmation (OCCTO form) | Approx. 1 month | None |
| Changes with grid impact (output increase, connection point change, etc.) | New connection review | 2-3 months | Approx. 200,000 yen |
Source:OCCTO "Grid Access Process for Generation Equipment" / Each T&D operator grid connection procedure guidelines
"Connection Review Necessity Confirmation" — The Most Important Procedure
When changing battery or PCS manufacturers, the "connection review necessity confirmation" procedure is typically used. This is an official procedure established by OCCTO (Organization for Cross-regional Coordination of Transmission Operators), with request forms published for high-voltage and extra-high-voltage applications.
What is the Connection Review Necessity Confirmation:
A procedure to confirm with the transmission and distribution operator whether a connection review is needed when making changes to all or part of generation equipment or ancillary equipment.
Scope: Changes to the battery itself, PCS (power conditioner) changes, ancillary equipment changes
Application to: The general transmission and distribution operator at the connection point
Response period: Approx. 1 month
Cost: Free (no review fee for the confirmation itself)
The response comes back as either "no re-review required" or "re-review is required."
Source:OCCTO Grid Access Procedure Form Collection https://www.occto.or.jp/access/kentou/youshiki.html
Conditions for "No Re-Review Required"
Conditions that tend to result in "no re-review required":
- Output (kW) remains unchanged — Changing equipment while keeping 50MW for a 50MW project
- Interconnection voltage unchanged — Remaining at 66kV
- Connection point unchanged — Same substation/tower
- Power factor and harmonic characteristics equal or better — New PCS electrical characteristics equivalent to original
- Short-circuit capacity contribution equal or less — No negative impact on grid stability
In other words, if the change "looks the same from the grid's perspective," no re-review is required.
Cases Where "Re-Review is Required"
Typical cases requiring re-review:
-
Output increase — e.g., expanding from 50MW to 60MW
-
Connection point change — Changing to a different substation
-
Interconnection voltage change — Changing from 66kV to 154kV
-
Significant changes to electrical characteristics affecting the grid
Tohoku Electric Power Network states "when there are changes to generation equipment specifications, in principle, a new receiving-side connection review application and review fee are required." However, this is "in principle," and there is sufficient room for the necessity confirmation procedure to determine "not required."
Source:Tohoku Electric Power Network "Grid Connection, Generation Adjustment Supply, and Power Sales Applications"
Practical Decision Framework
| Verification Item | Verification Method | Decision Criteria |
|---|
| Post-change output (kW) | New manufacturer specifications | No issue if equal to or less than original output |
| PCS electrical characteristics | Comparison of power factor, harmonics, short-circuit current | No issue if equal or better |
| Battery capacity (kWh) | New manufacturer specifications | Capacity changes have minimal grid impact |
| Connection voltage/point | Whether changed or not | No impact if unchanged |
| Physical equipment size | Layout review | No issue if it fits within the site |
| JC-STAR ★1 certification status | IPA conformity label grant list | After FY2027, uncertified PCS may face grid connection issues |
New Requirements for Equipment Selection — JC-STAR Cybersecurity Standards
When considering equipment changes from 2025 onwards, cybersecurity requirements must also be factored in. JC-STAR (Labeling Scheme based on Japan Cyber-Security Technical Assessment Requirements), operated by IPA (Information-technology Promotion Agency, Japan), is beginning to directly affect equipment selection including PCS.
Overview of JC-STAR
Official name: Labeling Scheme based on Japan Cyber-Security Technical Assessment Requirements (JC-STAR)
Operating body: IPA (Information-technology Promotion Agency, Japan), under the supervision of METI
Scope: IoT products with IP communication capabilities
Method: ★1 uses a
self-declaration of conformity (not third-party certification)
Conformity label applications opened on
March 25, 2025. On May 21, 2025, initial labels were granted to 477 products across 26 applications from 11 companies.
Source: IPA "JC-STAR" https://www.ipa.go.jp/security/jc-star/index.html
Grid Code Integration Policy
At the 20th Grid Code Study Group meeting (December 16, 2025), a policy was presented to incorporate the use of JC-STAR ★1 certified products for PCS in solar and battery storage systems into the Grid Code (grid interconnection technical requirements). The target is implementation as a requirement in FY2027 (Phase 2').
⚠ "Requirement," Not "Mandate" — Accurate Understanding is Important
JC-STAR ★1 is sometimes described as being "mandated," but the accurate description is that
a policy for making it a requirement has been presented. As of April 2026, formal regulation amendments have not been finalized, and the matter remains under deliberation. Rather than a legal obligation, it is expected to become a de facto essential condition by being incorporated into the Grid Code's technical requirements.
For low-voltage interconnection facilities under 50kW, a six-month transition period is planned with
application starting from October 2027, considering existing distribution inventory. However, this timeline is also a policy from the Grid Code Study Group, and formal confirmation awaits official regulation amendments.
Source: OCCTO 20th Grid Code Study Group Document 3 / Agency for Natural Resources and Energy 19th Grid Code Study Group Document 6
Products with ★1 Certification (as of October 2025)
| Manufacturer | Product | Certification Date | Product Category |
|---|
| SMA Japan | Sunny Central UP / Sunny Central Storage UP-XT | October 2025 | PCS (solar / bidirectional for BESS) |
| PowerX | Mega Power 2700A / Mega Power 2500 | October 2025 | Battery storage system (grid-scale) |
| Shizen Connect | Shizen Box / Shizen Box 2 | May 2025 | IoT device (gateway) *Not a PCS |
* JC-STAR covers IoT products with IP communication capabilities. It is not a safety evaluation scheme for battery cells or enclosures. Shizen Box is an IoT gateway, a different product category from PCS.
JC-STAR Checkpoints for Equipment Changes
- Verify that the replacement PCS has
obtained JC-STAR ★1 conformity label
- Given the planned FY2027 requirement, changing to a PCS without ★1 may cause grid connection issues
- Beyond PCS, IoT peripherals such as EMS and routers are also required to have JC-STAR ★1 for new installations under the ERAB Security Guidelines Ver3.0 (revised May 22, 2025)
Source: ERAB Security Guidelines Ver3.0 (revised May 22, 2025)
Four Facts Buyers of Development Rights Should Know
Fact 1: The Value of the Review Response Lies in "Confirming Grid-Side Conditions"
The essential economic value of the connection review response lies in having the connection point, interconnection voltage, and construction charges confirmed. Operator-side equipment specifications can be freely optimized within this "grid-side framework."
Fact 2: The Confirmation is "Free and Takes 1 Month"
The connection review necessity confirmation is free, with a response in approximately 1 month. Even if "re-review is required," the cost is approximately 200,000 yen and takes 2-3 months. The already-secured grid capacity and connection point are maintained; the procedure only confirms whether equipment specification changes affect the grid.
Fact 3: "Same Output, Same Voltage" Almost Always Passes
Keeping 50MW at 50MW, 66kV at 66kV, and only changing the manufacturer — cases where "re-review is required" for this pattern are limited. What affects the grid is output (kW) and connection conditions, not the battery cell manufacturer or PCS brand.
Fact 4: JC-STAR ★1 Certification Status Is a New Criterion for Equipment Selection
Given the policy to incorporate JC-STAR ★1 as a Grid Code requirement from FY2027, whether a replacement PCS has obtained the ★1 conformity label is now an important checkpoint during equipment changes. If the requirement is formally adopted, PCS without certification may not be permitted for new grid interconnection. It is advisable to confirm the manufacturer's certification status at the equipment change planning stage.
Summary: The connection review response is not an "equipment specification sheet" but a "grid access confirmation certificate"
The value of a development rights package lies in securing scarce grid access. Battery and PCS manufacturers can be selected by the buyer based on their optimal procurement strategy.
Change procedures are institutionalized, with limited costs and timeframes. The misconception that "changing equipment invalidates the rights" unnecessarily raises entry barriers.
Additionally, from FY2027 onwards, the planned Grid Code requirement for JC-STAR ★1 means that cybersecurity conformity label status must be verified when selecting PCS. While equipment change flexibility is maintained, it is important to recognize that a new dimension has been added to the selection criteria.
Sources & References:
- OCCTO "Grid Access Process for Generation Equipment"https://www.occto.or.jp/access/kentou/access_process.html
- OCCTO "Form Collection for Grid Access Procedures"https://www.occto.or.jp/access/kentou/youshiki.html
- Tohoku Electric Power Network "Grid Connection, Generation Volume Adjustment, and Power Sales Applications"https://nw.tohoku-epco.co.jp/consignment/request/emit/
- TEPCO Power Grid "High-Voltage and Extra-High-Voltage Construction Applications"https://www.tepco.co.jp/pg/consignment/fit/corporate.html
- OCCTO Transmission and Distribution Business Guidelines
- IPA "JC-STAR (Labeling Scheme based on Japan Cyber-Security Technical Assessment Requirements)" https://www.ipa.go.jp/security/jc-star/index.html
- OCCTO 20th Grid Code Study Group (December 16, 2025) Document 3
- Agency for Natural Resources and Energy 19th Grid Code Study Group Document 6
- ERAB Security Guidelines Ver3.0 (revised May 22, 2025)