Losing Japanese energy storage orders simply because of no JC-STAR certification?

“Products reached the port but were denied entry for lack of certification.”“Government subsidy applications rejected — reason: no JC-STAR.”

These are real experiences of dozens of energy storage manufacturers entering Japan since 2025.

JC-STAR (Japan Cyber STAR), launched in August 2024 by Japan’s Ministry of Economy, Trade and Industry (METI), has now become a mandatory pass for energy storage products sold in Japan.Unlike ordinary compliance certifications, it focuses on core cybersecurity requirements, catching many manufacturers off guard who are used to “shipping first, certifying later”.

Based on the latest official IPA guidelines, this article breaks down the key points of certification and helps you avoid fatal mistakes.

I. What Exactly Is JC-STAR?

JC-STAR is a cybersecurity labeling scheme for IoT products administered by Japan’s Information-Technology Promotion Agency (IPA).Its full name is Japan Cyber Security Technical Assessment Requirements Labeling Program.Its core purpose is to verify the security compliance of IoT products under unified standards.

• Core Positioning: Japan’s first national unified IoT security certification, compatible with international standards including ETSI EN 303 645 and NISTIR 8425
• Grading System: 4 levels (STAR‑1 to STAR‑4). STAR‑1 applications opened in March 2025; STAR‑2 to 4 target high‑security scenarios such as government and critical infrastructure
• Label Value: A scannable QR code label showing product security assessment and manufacturer info, widely used by buyers as a key reference

II. Which Energy Storage Products Must Be Certified?

Many manufacturers mistakenly believe only finished products need certification.In fact, any product with network connectivity that users cannot easily secure themselves requires JC-STAR.

✅ Mandatory for energy storage products:

• Residential / C&I Energy Storage Systems (ESS)
• Battery Management Systems (BMS), Power Conversion Systems (PCS)
• Energy storage monitoring platforms and communication gateways
• Supporting mobile apps and cloud management systems

❌ Exempt products:

• Pure mechanical parts (no network communication)
• General IT devices such as smartphones and PCs (users can install security software)

Critical Reminder:Component suppliers whose products are used in Japanese energy storage systems must also obtain JC-STAR separately, otherwise the entire system will be non-compliant.

III. Why Is JC-STAR Essential? 3 Core Benefits

1. Hard Market Access Threshold

Under new Japanese grid rules:Since March 2025, energy storage products without STAR‑1 certification are banned from grid connection.Power companies may refuse connection without it.No certification = no access to Japan’s energy storage market.

2. Required for Government Subsidies

Japan offers extremely high subsidies for energy storage:

• National subsidies: up to 66% of equipment cost
• Local subsidies: an extra 10%–20% in Tokyo, Osaka, etc.
• Utility procurement: major power companies including TEPCO and Kansai Electric only purchase JC-STAR labeled products

3. Supply Chain Competitive Edge

As Japanese enterprises strengthen supply chain security, JC-STAR has become a core vendor selection criterion.Certified manufacturers can priority enter supply chains of Mitsubishi, Sumitomo and other large enterprises, escaping low‑price competition.

IV. Certification Process: STAR‑1 in as Fast as 5 Weeks?

Despite common misconceptions, STAR‑1 uses a self‑declaration + official review model and is simpler than expected:

1. Product Classification & Level Confirmation (1 day)Energy storage products default to STAR‑1 for basic compliance.

2. Self-Assessment & Evidence Preparation (1–2 weeks)Prepare security design docs, vulnerability management procedures, test reports against the STAR‑1 checklist.

3. Application Submission (1–3 days)Use the revised July 2025 STAR‑1 form and submit via IPA’s designated platform.

4. Official Review (2–4 weeks)IPA checks document completeness; may request supplements (no on-site audit).

5. Payment & Certification (within 1 week)Official fee: 198,000 JPY (≈ 9,500 RMB). Label valid for 2 years.

6. Label UsageAffix the QR‑code label and keep assessment records for random IPA inspections.

Important Update:From April 2026, products compliant with the UK PSTI Act can reuse partial documents to shorten the process.

V. STAR‑1 Core Test Requirements for Energy Storage

STAR‑1 focuses on basic cybersecurity capabilities.Energy storage products must pass these key checks:

1. Identity Authentication: No default weak passwords; password complexity enforced
2. Communication Security: Encrypted transmission (HTTPS/TLS 1.2+); anti‑eavesdropping & anti‑tampering
3. Vulnerability Management: Formal processes for reporting, fixing and disclosing vulnerabilities
4. Log Audit: Critical operation logs retained ≥ 90 days with traceability
5. Secure Updates: Firmware/software OTA with anti‑hijacking protection
6. Access Control: Separate admin / user permissions; prevent privilege escalation
7. Physical Security: Restricted access to USB, debug ports and other critical interfaces
8. BMS Special Requirements: Anti‑tampering for battery parameters; safe charge/discharge control

VI. Timeline & Cost (2026 Latest)

Certification Cycle

• Fastest: 3–5 weeks (complete documents, no revisions)
• Standard: 6–8 weeks (minor fixes needed)
• Longest: 10+ weeks (major redesign for security flaws)

Cost Breakdown

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VII. Top 8 Failure Points for Energy Storage Products

Based on GTG Lab’s experience assisting dozens of manufacturers, 90% of failures come from these issues:

• Default BMS passwords (e.g., admin/123456) not removed and unchangeable
• Log retention < 90 days or missing records for key operations
• Unencrypted plaintext communication between BMS, PCS and cloud
• No secure OTA or missing firmware integrity verification
• No formal vulnerability management or user notification system
• Unclear permission control: regular users can modify charge/discharge thresholds
• Unprotected debug/USB ports accessible without authentication
• Inconsistent documentation: encryption claimed but not actually enabled

Conclusion

Japan’s energy storage market is expected to exceed 500 billion yen in 2026.Compliance is the first step to capturing this opportunity.JC-STAR is not an extra cost — it is the key to market entry, subsidies and trust in Japan.

If you are exporting to Japan or preparing certification documents,send a message to get the JC-STAR Energy Storage Self-Inspection Checklistor book a free GTG pre-test to identify risks early.