Certification for Wind Turbines

ClassNK offers a variety of certification services for wind turbines

ClassNK conducts certification for wind turbines based on the IEC 61400 international series of standards. ClassNK also offers a wide variety of services that respond to the needs of the renewable energy industry based on the ClassNK Guidelines for Certification of Wind Turbines and Wind farms created in line with IEC 61400-22 requirements.

Large Wind Turbines

Certification Services

ClassNK performs various evaluations for large wind turbines based on related standards and technical requirements such as “Design Evaluation” and “Prototype Certification for type testing”, finally issuing “Type Certificate” once the applicable standards have been satisfied.

Registrations of wind turbine certification

Project Certification

ClassNK conducts certification for wind power generation facilities covering site-specific environmental conditions, wind turbines and their support structures, from development, through to construction and even after operation to confirm conformity with the relevant technical standards.

Wind Farm Certification

Wind Farm Certification is covered as part of the project certification process and is carried out to ensure conformity with the safety regulations of the Electricity Business Act for “Construction Plan Notification”. ClassNK evaluates the environmental conditions of the proposed installation site and assesses whether the strength and safety of the wind turbines and their support structures are suitable for the installation environment based on Japan-specific requirements.

Registrations of wind farm certification

Floating Offshore Wind Turbine Certification

Although floating offshore wind turbines are subject to regulations in the Electricity Business Act, their towers, floating structures, and mooring systems are subject to Ship Safety Law. ClassNK carries out a wide range of classification related services such as design evaluation, inspection of materials, components, and structures in addition to site surveys as an accredited third-party organization in accordance with the Ship Safety Law requirements and its own Guidelines for Floating Offshore Wind Turbine Structures.

Guidelines for Certification of Wind Turbines and Wind Farms 2.9MB
Guidelines for Floating Offshore Wind Turbines Structures 0.5MB

Small Wind Turbines

Type Certification

ClassNK performs evaluations for small wind turbine systems with an output of less than 20kW to ensure that they meet requirements specified in domestic and international standards established by IEC and JIS, issuing type certificates once it has confirmed conformity to the applicable standards. ClassNK type certifications for small wind turbines also ensure eligibility for the Feed-in Tariff Scheme launched by the Japanese government as part of efforts to promote the use of renewable energy. ClassNK was accredited by Japan Accreditation Board as Product Certification Body for Wind Turbine Products (Small Wind Turbine Type Certification) in May 2013.


Unauthorized use prohibited.

ClassNK publishes the following documents for the type certification of small wind turbines.

Guidance for Certification of Products PDF
Type Certification Service for Small Wind Turbines ( Leaflet ) PDF
Registrations of Wind Turbine Type Certification PDF
Appeals handling and complaints handling Processes PDF

Please apply for the type certification of small wind turbines by using the following templates.

Application for Product Certification ( Template ) PDFWord
Request for Quotation ( Template ) PDFWord

Certification for Support Structures of Small Wind Turbines

Electrical power suppliers have a responsibility to ensure that the support structures of small wind turbines such as towers and foundations are compliant with requirements specified in the Electricity Business Act. ClassNK performs plan approvals and conducts site surveys as a third party organization to confirm compliance with these requirements.

Registrations of Certification for Support Structures of small wind turbines (Japanese)

Address and Contact Details
Renewable Energy Department
4-7 Kioi-cho, Chiyoda-ku, Tokyo 102-8567, Japan
Tel : +81-3-5226-2032 Fax : +81-3-5226-2060 email : re@classnk.or.jp