Project Certification of Offshore Wind Farms

Transcription

1 OFFSHORE SERVICE SPECIFICATION DNV-OSS-901 Project Certification of Offshore Wind Farms JUNE 2012 The electronic pdf version of this document found through is the officially binding version

2 FOREWORD DET NORSKE VERITAS (DNV) is an autonomous and independent foundation with the objectives of safeguarding life, property and the environment, at sea and onshore. DNV undertakes classification, certification, and other verification and consultancy services relating to quality of ships, offshore units and installations, and onshore industries worldwide, and carries out research in relation to these functions. DNV service documents consist of among others the following types of documents: Service Specifications. Procedural requirements. Standards. Technical requirements. Recommended Practices. Guidance. The Standards and Recommended Practices are offered within the following areas: A) Qualification, Quality and Safety Methodology B) Materials Technology C) Structures D) Systems E) Special Facilities F) Pipelines and Risers G) Asset Operation H) Marine Operations J) Cleaner Energy O) Subsea Systems Det Norske Veritas AS June 2012 Any comments may be sent by to This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of this document, and is believed to reflect the best of contemporary technology. The use of this document by others than DNV is at the user's sole risk. DNV does not accept any liability or responsibility for loss or damages resulting from any use of this document.

3 Introduction Page 3 General This document replaces the DNV document DNV Project Certification Scheme, General Scope of Work for Project Certification of Offshore Wind Farms,

4 Contents Page 4 CONTENTS Sec. 1 INTRODUCTION... 7 A. General... 7 A 100 Objectives... 7 A 200 Scope of application... 7 A 300 Organization of the OSS... 7 A 400 Hierarchy of DNV Offshore Publications... 7 B. Definitions... 8 B 100 General... 8 B 200 Verbal forms... 8 B 300 Terms... 8 B 400 Acronyms... 9 B 500 Symbols C. References C 100 General C 200 DNV documents C 300 IEC documents C 400 ISO documents C 500 Other documents Sec. 2 SERVICE OVERVIEW A. General A 100 Objective A 200 Selection of certification system B. DNV Project Certification B 100 Certification phases B 200 Basis and procedure B 300 Deliverables B 400 Validity and maintenance of certificate C. Certification to the IEC System C 100 General D. Certification to National Approval Systems D 100 General on national requirements D 200 National requirements in relation to the DNV system D 300 Danish Project Certification System D 400 Other national systems E. Maintenance of Project Certificate E 100 Period of validity E 200 Maintenance of certificate E 300 Recertification F. Accredited Project Certification F 100 Accreditations G. Client DNV Interaction G 100 Documentation requirements G 200 Deliverables and Schedule H. Combination of Codes and Standards H 100 General Sec. 3 DETAILED SERVICE DESCRIPTION: WIND TURBINE AND SUPPORT STRUCTURE A. Introduction A 100 Objective B. Phase I: Verification of Design Basis B 100 General B 200 Site conditions B 300 Codes, standards and requirements B 400 Design criteria B 500 Load-out, transport, installation and commissioning B 600 Operation and maintenance C. Phase II: Verification of Design C 100 General... 22

5 Contents Page 5 C 200 Load and response C 300 Wind turbine type C 400 Wind turbine C 500 Primary support structure C 600 Secondary structures C 700 Tertiary structures C 800 Other installations C 900 Load-out, transportation, installation and commissioning plan C 1000 Operation and maintenance plan D. Phase III: Manufacturing Survey D 100 General D 200 Survey of wind turbine and components D 300 Survey of support structure E. Phase IV: Installation Survey E 100 General E 200 Installation survey E 300 Warranty survey F. Phase V: Commissioning Survey F 100 General F 200 Commissioning survey G. Phase VI: In-service Surveys G 100 General G 200 Surveys G 300 Wind turbine G 400 Submerged structures G 500 Validation of certificate Sec. 4 DETAILED SERVICE DESCRIPTION: SUBSTATION TOPSIDE AND SUPPORT STRUCTURE A. Introduction A 100 Objective B. Phase I: Verification of Design Basis B 100 General B 200 Site conditions B 300 Codes, standards and requirements B 400 Design criteria B 500 Load-out, transportation, installation and commissioning B 600 Operation and maintenance C. Phase II: Verification of Design C 100 General C 200 Structural design and geotechnical design C 300 Primary structures C 400 Secondary structures C 500 Tertiary structures C 600 Electrical design C 700 Fire and explosion protection design C 800 Access and transfer design C 900 Emergency response design C 1000 Load-out, transportation, installation and commissioning plan C 1100 Operation and maintenance plan D. Phase III: Manufacturing Survey D 100 General D 200 Topside structure D 300 Topside equipment D 400 Support structure E. Phase IV: Installation Survey E 100 General E 200 Installation survey E 300 Warranty survey F. Phase V: Commissioning Survey F 100 General F 200 Commissioning survey G. Phase VI: In-service Surveys G 100 General G 200 Surveys G 300 Substation... 43

6 Contents Page 6 G 400 Submerged structures G 500 Validation of certificate App. A SAMPLE CERTIFICATION DOCUMENTS A. Sample Statement of Compliance A 100 Sample statement of compliance B. Sample Project Certificate B 100 Sample project certificate... 46

7 Sec.1 Page 7 SECTION 1 INTRODUCTION A. General A 100 Objectives 101 This Offshore Service Specification (OSS) specifies DNV s service for project certification of offshore wind farms. 102 The document has a dual function in that it provides a common communication platform for describing the scope and extent of activities performed for project certification of wind farms. forms a reference document for defining the scope of work in accordance with requirements by the applicable certification system. 103 This OSS is an object-specific detailed service specification conforming to the philosophy defined in DNV-OSS-300 Risk-Based Verification, Sec.1E. The service specified in this OSS is in compliance with the IEC Project Certification System described in IEC DNV s project certification service includes certification to the DNV Project Certification System, based on DNV standards, as well as certification to other certification systems, based on other standards. 105 The project certification concept for offshore wind farms constitutes a robust means to provide, through independent verification, evidence to stakeholders (financiers, partners, utility companies, insurance companies and the public) that a set of requirements laid down in standards are met during design and construction, and maintained during operation, of an offshore wind farm. 106 The OSS describes the activities which are necessary to be carried out to obtain a DNV Project Certificate and it describes how to maintain this certificate by periodical validation during the service life of the wind farm. 107 This document has a dual objective: It serves as a publicly available description of DNV s project certification service for offshore wind farms and it will be referred to as a contractual document in the project certification contract between the client and DNV. The document specifies the obligations of the client when his wind farm is to become certified, as well as DNV s service obligations to the client. A 200 Scope of application 201 This OSS applies to project certification and related verification tasks during the design, construction and operation of offshore wind farms. 202 The following two assets of offshore wind farms are covered by the service: Wind turbines and their support structures Substations including topsides and support structures. 203 Each asset may be further subdivided into elements. In this OSS, the term element is used for the following components: Wind turbines Support structures for wind turbines Substation topsides Support structures for topsides. A 300 Organization of the OSS 301 The OSS is divided into four main sections. Sec.1 provides general information about project certification of offshore wind farms. Sec.2 provides a general service overview. Sections 3 and 4 provide detailed descriptions of the service. Sec.3 contains details of the service concerned with the wind turbine and the support structure. Sec.4 contains details of the service concerned with the substation. A 400 Hierarchy of DNV Offshore Publications 401 DNV Offshore Publications are organized according to a three-level document hierarchy, with these main features: Principles and procedures related to DNV s certification and verification services are separate from technical requirements and are presented in DNV Offshore Service Specifications Technical requirements are issued as self-contained DNV Offshore Standards Associated product documents are issued as DNV Recommended Practices.

8 Sec.1 Page The hierarchy in 401 is designed with these objectives: Offshore Service Specifications present the scope and extent of DNV s services Offshore Standards are issued as neutral technical standards to enable their use by national authorities, as international codes and as company or project specifications without reference to DNV s services Recommended Practices provide DNV s interpretation of safe engineering practice for general use by industry. Guidance note: The latest revision of all DNV documents may be found in the publications list on the DNV web site ---e-n-d---of---g-u-i-d-a-n-c-e---n-o-t-e--- B. Definitions B 100 General 101 The definitions in the DNV standards DNV-OS-J101 Design of Offshore Wind Turbine Structures and DNV-OS-J201 Offshore Substations for Wind Farms apply for this OSS. Key definitions and specific definitions for this OSS are given in B300. B 200 Verbal forms 201 The terms will, can and may are used when describing DNV s actions and activities, whereas the terms shall, should and may are used when referring to actions and activities by other parties than DNV. 202 Shall: Indicates requirements strictly to be followed in order to conform to this OSS and from which no deviation is permitted. 203 Should: Indicates that among several possibilities, one is recommended as particularly suitable, without mentioning or excluding others, or that a certain course of action is preferred but not necessarily required. Other possibilities may be applied subject to agreement. 204 Will: Indicates a mandatory action or activity to be undertaken by DNV (in contrast to the use of shall for other parties). 205 Can: Indicates an action or activity which DNV does not necessarily undertake unless specifically required by the client (in contrast to the use of should for other parties). Can may also indicate an action or activity which DNV wants to undertake even if not specifically required by the client. 206 May: Verbal form used to indicate a course of action permissible within the limits of the OSS. B 300 Terms 301 Asset: Term used in the context of offshore wind farm projects to describe the project or object to be developed, manufactured and maintained. In this OSS the term refers either to Wind Turbines with Support Structures or to Offshore Substation. 302 Certification: Action by a certification body, providing written assurance that adequate confidence is provided that the asset in question is demonstrably in conformity with a specific standard or other normative document. Certification is the final statement that all requirements of a standard or normative document have been satisfied or conformed to. 303 Client: DNV s contractual partner. 304 Condition: The term Condition is used for a major Outstanding Issue which would signify a deviation from a major technical requirement, and which could seriously affect the intended operation of the wind farm. In case of a Condition, a Project Certificate will not be issued until the outstanding issue has been rectified. In special cases, project certificates can be issued with very limited outstanding issues. See Sec.2 G Conformity Statement: IEC term for Statement of Compliance. 306 Det Norske Veritas (DNV): An autonomous and independent foundation with the purpose of safeguarding life, property and the environment. The foundation operates through the limited company Det Norske Veritas AS, which is registered in Norway and operates through a worldwide network of offices. 307 Element: A system or a component that forms part of an asset. In this OSS, the term refers to rotor nacelle assembly (wind turbine excluding tower), support structure for wind turbine (tower, substructure and foundation), topside equipment, and support structure for substation (topside structure, substructure and foundation). 308 Foundation: The part of the support structure for an offshore wind turbine or substation that transfers the loads acting on the structure into the seabed. 309 Offshore Wind Farm Project: Term referring to the total number of wind turbines including support structures within a wind farm. A substation may be defined as an integral element of the Offshore Wind Farm Project or as a separate asset.

9 Sec.1 Page Optional: Optional services are services which are not part of the scope which is required in order to obtain statements of compliance and project certificates. 311 Other installations: Installations such as cables, secondary structures and other equipment. The cables comprise cables between the substation and the wind turbines and between the substation and the main grid. 312 Outstanding Issue: The term Outstanding Issue is used to denote a deviation from standards and technical requirements specified in the contract, and which needs to be completed for full compliance. Outstanding issues will be noted on the Statement of Compliance issued, see Sec.2 G Primary Structure: The primary structure consists of the load-bearing structure that transfers permanent loads and environmental loads, caused by gravity and environment and acting on the support structure, to the seabed. 314 Project Certificate: A document signed by DNV and affirming that, at the time of assessment, the asset referred to on the certificate met the stated requirements. 315 Recommendation: Non-mandatory advice. 316 Secondary Structure: Secondary structures are boat landings, access ladders, access platforms and J- tubes, which shall be covered by a risk-based verification before a Statement of Compliance can be issued. Note that J-tubes on substations are defined as part of the primary structure. 317 Statement of Compliance: Term referring to a document signed by DNV and affirming that, at the time of assessment, the defined certification phase, project phase or natural part of the project met the stated requirements. In the IEC system, this document is referred to as a Conformity Statement. 318 Substation: Term referring to transformer platforms and converter platforms, with or without accommodations. An offshore substation may be defined as an integral element of the offshore wind farm project or as a separate asset for DNV Project Certification. 319 Substructure: Term referring to the part of the support structure for an offshore wind turbine which extends upwards from the seabed and connects the foundation and the tower. The term is also used to designate the part of the support structure for a substation which extends upwards from the seabed and connects the foundation and the topside. 320 Support Structure: The support structure for an offshore wind turbine is defined as the structure below the yaw system of the wind turbine and includes the tower structure, the substructure and the foundation. The term is also used to designate the topside structure, substructure and foundation for an offshore substation. 321 Tertiary Structure: Structural items such as internal ladders and platforms, stairs, gratings and handrails. 322 Verification: Verification consists of evaluating and checking information to establish that an object in question meets a technical requirement or standard. Multiple verification activities are performed and successfully completed to support the decision to issue a statement of compliance. 323 Wind Turbine: System which converts kinetic energy in the wind into electrical energy. For wind turbines in an offshore wind farm project subject to DNV Project Certification, the wind turbine is limited to the rotor and nacelle assembly and the electrical installations and secondary structures located inside the tower. B 400 Acronyms 401 Acronyms as given in Table B1 are used in this service specification. Table B1 Acronyms Acronym AC ALS BEK BOEMRE BSH CVA DANAK DC DNV FEM FLEX5 FLS HAWC IEC ISO In full Alternating current Accidental Limit State Bekendtgørelse (Executive order, in Danish) Bureau of Ocean Energy Management, Regulation and Enforcement Bundesamt für Seeschifffart und Hydrographie Certified Verification Agent Den Danske Akkrediterings- og Metrologifond (The Danish Accreditation and Metrology Fund, in Danish) Direct current Det Norske Veritas Finite Element Method Computer program for simulation of wind turbine dynamics Fatigue Limit State Horizontal axis wind turbine simulation code International Electrotechnical Commission International Organization for Standardization

10 Sec.1 Page 10 Table B1 Acronyms (Continued) Acronym In full NDT Non-destructive testing NVN Nederlandse Voor Norm (Dutch pre-norm, in Dutch) O&M Operation and Maintenance OWF Offshore Wind Farm QA Quality Assurance ROV Remotely Operated Vehicle SLS Serviceability Limit State SoC Statement of Compliance TR Technical Report TS Technical Specification ULS Ultimate Limit State US United States WT Wind Turbine B 500 Symbols 501 Symbols as given in Table B2 are used in this service specification. Table B2 Symbols Symbol Interpretation C d Hydrodynamic drag coefficient Hydrodynamic inertia coefficient C m C. References C 100 General 101 This document makes reference to relevant DNV Rules and Standards and to international codes and standards. Unless otherwise specified in the certification agreement or in this OSS, the latest valid revision of each referenced document applies. C 200 DNV documents 201 DNV rules, standards and service descriptions of relevance for offshore wind farms are listed in Table C1. Table C1 DNV documents Reference DNV-DSS-904 DNV-OSS-300 DNV-OS-B101 DNV-OS-C101 DNV-OS-C401 DNV-OS-C502 DNV-OS-H101 DNV-OS-J101 DNV-OS-J201 DNV-OS-J301 Standard for Certification No Title Type Certification of Wind Turbines Risk Based Verification Metallic Materials Design of Offshore Steel Structures, General (LRFD Method) Fabrication and Testing of Offshore Structures Offshore Concrete Structures Marine Operations, General Design of Offshore Wind Turbine Structures Offshore Substations for Wind Farms Standard for Classification of Wind Turbine Installation Units Lifting Appliances Rules for Planning and Execution of Marine Operations

11 Sec.1 Page 11 C 300 IEC documents 301 IEC documents of relevance for offshore wind farms are listed in Table C2. Table C2 IEC documents Reference Title IEC Wind Turbines Part 1: Design requirements IEC Wind Turbines Part 3: Design requirements for offshore wind turbines IEC Wind Turbines Part 22: Conformity Testing and Certification IEC Electrical installations for buildings ISO/IEC General requirements for the competence of calibration and testing laboratories C 400 ISO documents 401 ISO documents of relevance for offshore wind farms are listed in Table C3. Table C3 ISO documents Reference Title ISO 9001 Quality management systems requirements C 500 Other documents 501 Other documents of relevance for offshore wind farms are listed in Table C4. Table C4 Other documents Reference Title Eurocode 7 Geotechnical design Part 2: Ground investigation and testing

12 Sec.2 Page 12 SECTION 2 SERVICE OVERVIEW A. General A 100 Objective 101 The objective of this section is to provide an overview of the activities performed for project certification of offshore wind farms. Certification according to various certification systems are dealt with. A 200 Selection of certification system 201 The certification system to be applied for the certification shall be agreed in the contract between the client and DNV. 202 Project certification of wind farms is carried out according to one of several project certification systems. The following project certification systems are available and recognized by DNV: DNV Project Certification System IEC Project Certification System Danish Project Certification System. DNV also offers project certification of wind farms according to certification systems by BSH under German jurisdiction and as CVA according to US legislation, but not as an accredited service. B. DNV Project Certification B 100 Certification phases 101 DNV Project Certification is a particular form of certification where the total scope of the involved activities is defined by DNV. For project certification of Offshore Wind Farms (OWF) this OSS defines the scope. 102 The DNV Project Certification System consists of six modules, see Figure 1. The modules refer to five particular phases during the design and construction and to one in-service phase. I Design Basis DNV Project Certificate Statement of Compliance II Design Statement of Compliance III Manufacturing Statement of Compliance IV Installation Statement of Compliance V Commissioning Statement of Compliance Maintenance of Certificate Figure 1 The phases of a DNV Project Certification VI In- Service 103 Phases I and II cover the steps necessary to achieve final design verification. This verification includes a site-specific design approval of the integrated structural system consisting of wind turbine and support structure or substation topside and support structure. 104 Phases III through V involve all follow-up verification and on-site inspections during the implementation of the project. 105 Phase VI involves follow-up verification and on-site inspections after the completion of the project and during the in-service period.

13 Sec.2 Page Each phase will be completed with the issue of a Statement of Compliance. After completion of Phases I through V for the wind turbine and the support structure or for the substation, a DNV Project Certificate will be issued. The certificate documents compliance with specified or agreed standards at the date of issue. 107 Statements of compliance may be issued with no or minor outstanding issues. An outstanding issue on a statement of compliance implies that the outstanding issue regarding compliance with specified or agreed standards have not been rectified. 108 The project certificate may be issued with minor outstanding issues. An outstanding issue on a project certificate implies that the outstanding issue regarding compliance with specified or agreed standards have not been rectified. The project certificate may be validated throughout the in-service phase VI. For validation throughout the in-service phase, reference is made to Sec.3G and Sec.4G. 109 On request, complementary services to DNV Project Certification may be performed and will then be documented separately. Such services may include precertification services, for example verification of project planning and permitting, and pre-design evaluation and warranty surveys. 110 The DNV Project Certification System is in compliance with the IEC Project Certification System as specified in IEC Conformity Testing and Certification of Wind Turbines. B 200 Basis and procedure 201 DNV-OS-J101 and DNV-OS-J201 in conjunction with their respective referenced DNV standards and rules provide the technical key requirements to be fulfilled for the assets subject to the project certification. 202 Wherever DNV-OS-J101 and DNV-OS-J201 refer to acceptance, agreement and qualification, this shall be by DNV. 203 In essence project certification consists of a series of verification activities. The extent of these activities is defined in this OSS and the activities are organized in phases. Following a successful completion of a phase, DNV issues a Statement of Compliance (SoC). 204 The requirement for obtaining a DNV Project Certificate is that a SoC has been issued by DNV for each of the five Phases I through V. 205 For each certification phase, the assets covered by the project certification can be subdivided into elements as defined in Sec.1 A307. One SoC is issued for each individual element verified in the phase or one common SoC is issued for all elements verified in the phase. For example, for the Design Basis Phase separate SoCs can be issued for the elements Wind Turbine and Support Structure or one common SoC covering both the wind turbine and the support structure can be issued for the Design Basis phase. 206 Following the successful completion of a project certification of an offshore wind farm project, DNV issues project certificates for offshore wind farm assets, which are either the wind turbines with support structures or the substation topsides with support structures, or both, depending on the agreed scope of the certification. B 300 Deliverables 301 A DNV Project Certificate can be issued for an offshore wind farm asset as defined in this OSS. Possible project certificates are certificates for wind turbines and their support structures substations including topside components and support structures. B 400 Validity and maintenance of certificate 401 The DNV Project Certificate refers to statements of compliance issued for the completed phases of the project certification. The project certificate is valid for one year after the date of first issuance. 402 When an in-service agreement for the wind farm is in place between DNV and the client, the validity of the project certificate is extended to the duration of the service agreement plus one year; however, five years is the maximum period of validity. 403 Maintenance of the certificate is conditioned on: annual reporting by client covering the certified wind farm project and including information about installed turbines and additional installations as installed on the site deviating operating experience minor modifications reporting by client of planned major modifications without delay the wind farm and the turbines and structures that it comprises are maintained at a standard complying with the requirements of applicable codes and relevant manuals periodical surveys by DNV. A statement of compliance that validates the certificate will be issued on the basis of successful periodical in-service surveys.

14 Sec.2 Page 14 Table B1 Phases of DNV Project Certification and associated activities for wind turbine and support structure; references are to subsection numbers in Sec.3. PHASES ELEMENTS Rotor nacelle assembly (wind turbine exclusive of tower) Support structure (tower, substructure and foundation) I. Design Basis B 200 Site conditions B 300 Codes, standards and requirements B 300 Codes, standards and requirements B 400 Design criteria B 400 Design criteria B 500 Transport, installation and commissioning B 500 Transport, installation and commissioning B 600 Operation and maintenance B 600 Operations and maintenance II. Design C 200 Load and response C 300 Wind turbine type C 400 Wind turbine C 900 Load-out, transportation, installation and commissioning plan C 1000 Operation and maintenance plan C 500 Primary support structure C 600 Secondary structures C 700 Tertiary structures C 800 Other installations C 900 Load-out, transportation, installation and commissioning plan C 1000 Operation and maintenance plan III. Manufacturing D 200 Survey of wind turbine and components D 300 Survey of support structure IV. Transport and Installation E 200 Installation survey E 200 Installation survey V. Commissioning F 200 Commissioning survey F 200 Commissioning survey VI. In-Service G 200 Surveys G 300 Wind turbine G 500 Validation of certificate G 200 Surveys G 400 Submerged structures G 500 Validation of certificate Table B2 Phases of Project Certification and associated activities for substation topside and support structure; references are to subsection numbers in Sec.4. PHASES ELEMENTS Substation topside (topside structure, fire and safety, topside Substation support structure (substructure and foundation) equipment, escape routes) (optional: helideck, crane, electrical components, ventilation system, etc.) I. Design Basis B 200 Site conditions B 300 Codes, standards and requirements B 300 Codes, standards and requirements B 400 Design criteria B 400 Design criteria B 500 Load-out, transportation, installation and commissioning B 600 Operation and maintenance B 500 Load-out, transportation, installation and commissioning B 600 Operation and maintenance II. Design C 200 Structural design C 200 Structural design and geotechnical design III. Manufacturing C 300 Primary structures C 400 Secondary structures C 500 Tertiary structures C 600 Electrical design* C 700 Fire and explosion protection design C 800 Access and transfer design C 900 Emergency response design C 1000 Load-out, transportation, installation and commissioning plan C 1100 Operation and maintenance plan D 200 Topside structure D 300 Topside equipment E 200 Installation survey C 300 Primary structures C 400 Secondary structures C 500 Tertiary structures C 1000 Load-out, transportation, installation and commissioning plan C 1100 Operation and maintenance plan D 400 Support structure IV. Transport E 200 Installation survey and Installation V. Commissioning F 200 Commissioning survey F 200 Commissioning survey VI. In-Service G 200 Surveys G 300 Topside G 500 Validation of certificate * Electrical design is currently optional as it is not covered by DNV-OS-J201, G 200 Surveys G 300 Support structure above water G 400 Submerged structures G 500 Validation of certificate

15 Sec.2 Page The verification activities associated with the various elements and certification phases covered by Tables B1 and B2 are presented in more detail in Sections 3 and Warranty surveys are not part of the project certification scope, but can be carried out as an optional additional service. C. Certification to the IEC System C 100 General 101 Wind farm projects can be certified to the IEC system, which is specified in IEC Conformity Testing and Certification of Wind Turbines and which refers to requirements in IEC and IEC DNV offers certification of wind farm projects to the IEC system. The DNV certification according to the IEC system and according to the DNV system defined in Subsection B are mutually compliant. The extent of the verification activities necessary to lead to the issue of a certificate according to the IEC system are defined in IEC With a view to certification according to the IEC system, the objective of this OSS is to detail and clarify the verification activities within the IEC system and to fill gaps in the governing IEC standards, in particular with respect to representation of the structural capacity in design. 104 DNV-OS-J101 and DNV-OS-J201 can be used as guidance and serve as DNV s interpretation of the requirements of IEC , IEC and IEC for offshore wind farms. 105 The IEC system covers a number of certification phases. A conformity statement is issued at the completion of the verification activities for each certification phase within the IEC system. The conformity statement is analogous to the statement of compliance issued at the completion of a certification phase within the DNV system. 106 Mandatory and optional certification phases in the IEC system are outlined in Figure 2, in which the certification phases according to the DNV system are included for comparison. The DNV system complies with the IEC system with the main difference that some DNV phases comprise multiple IEC phases. The number of conformity statements issued when the IEC system is followed for the certification will therefore be larger than the number of statements of compliance issued when the DNV system is followed. Another difference between the two systems consists of slightly differently formulated requirements in a few cases where the IEC requirements are relatively openly formulated and where the corresponding DNV requirements have been subject to a reformulation for clarity. However, as the IEC system and the DNV system are mutually compliant, the IEC system is fulfilled when the DNV system is followed for the certification, and vice versa. Type Certificate Wind Turbine / RNA Design Evaluation Site Conditions Assessement Design Basis Evaluation Integrated Load Analysis Support Structure Design Evaluation Other Installations Design Evaluation Design Basis Design Wind Turbine / RNA Manuf. Surveillance Support Structure Manuf. Surveillance Other Installations Manuf. Surveillance Manufacturing Transportation & Install. Surveillance Installation Commissioning Surveillance Commissioning Project Characteristics Measurements Final Evaluation Project Certificate Operations & Maintenance Surveillance Inservice Project Certificate Mandatory Optional Figure 2 IEC certification phases (blue) in comparison with DNV Project Certification phases (green)

16 Sec.2 Page 16 D. Certification to National Approval Systems D 100 General on national requirements 101 Wind farms can be certified to national approval systems for offshore wind farms. DNV offers certification to such national approval systems. 102 For certification to national approval systems for offshore wind farms, the pertinent national rules and regulations form the requirements for the DNV certification. These requirements need to be fulfilled in order to allow a project certificate to be issued for an offshore wind farm. 103 DNV-OS-J101 and DNV-OS-J201 can be used as guidance and serve as DNV s interpretation of the requirements of the national rules and requirements in question. D 200 National requirements in relation to the DNV system 201 National approval systems may impose requirements which come in addition to the requirements of the DNV system. The DNV system may also contain requirements which come in addition to the national requirements. 202 For DNV s approval and for DNV to issue statements of compliance in connection with certification to national approval systems, all requirements set forth in the DNV system need to be fulfilled. Guidance note: This policy is in force on the grounds that DNV needs to verify that requirements for safety level are met before DNV can issue statements of compliance. ---e-n-d---of---g-u-i-d-a-n-c-e---n-o-t-e--- D 300 Danish Project Certification System 301 Project certification is according to the Danish Energy Agency Executive Order No. 651, D 400 Other national systems 401 National systems and standards are in place for Germany and the United States. These standards include requirements which come in addition to those set forth by IEC and they require appropriate national bodies for the final approval. 402 Germany: Bundesamt für Seeschifffart und Hydrographie (BSH) Standard Konstruktive Ausführung von Offshore-Windenergieanlagen. BSH-Nr. 7005, June 12, United States: BOEMRE. Federal Register 30 CFR Parts 250, 285 and 290 Renewable Energy and Alternative Uses of Existing Facilities on the Outer Continental Shelf; Final Rule. E. Maintenance of Project Certificate E 100 Period of validity 101 The validity period of a project certificate for a wind farm is one year from the date of first issuance. 102 When an in-service agreement for the wind farm is in place between DNV and the client, the validity period of the project certificate is extended to the duration of the service agreement plus one year; however, five years is the maximum period of validity. E 200 Maintenance of certificate 201 Maintenance of the project certificate is conditioned on periodical surveys by DNV. 202 A statement of compliance that validates the certificate will be issued on the basis of successful periodical in-service surveys. E 300 Recertification 301 DNV may require recertification if additional requirements for maintenance of the project certificate are set by national authorities or by the applicable design code or standard during the validity period of the certificate. 302 Major revision to a referenced standard as well other new industry learning during the validity period for a project certificate will be evaluated by DNV. If such a revision is judged to have implications for the integrity and safety of the certified wind farm, the wind farm will have to be modified and/or re-evaluated in order to retain its project certificate. Transition periods and guidance for implementation of new revisions will be established by DNV for each individual case.

17 Sec.2 Page 17 F. Accredited Project Certification F 100 Accreditations 101 DNV is accredited for project certification of wind farms according to systems as specified in DNV is accredited for project certification of wind farms according to the following systems: DNV Project Certification System according to DNV-OSS-901, 2012 Offshore and Onshore Wind Turbine Parks according to Danish Energy Agency Executive Order No. 651, Executive Order on the Technical Certification Scheme for the Design, Manufacture, Installation, Maintenance and Service of Wind Turbines Offshore and onshore Wind Turbine Parks according to IEC Wind turbines Part 22: Conformity testing and certification, Section The accreditation is granted by DANAK and is limited to DNV Denmark (Det Norske Veritas, Danmark A/S). G. Client DNV Interaction G 100 Documentation requirements 101 The documentation packages pertaining to each task listed in Tables A1 and A2 and provided to DNV by the client shall be complete and self-explanatory. 102 The documentation shall be provided to DNV in a logical sequence to facilitate cross checking between documents. 103 The documentation, including codes and standards as well as other requirements and specifications, shall be prepared in the English language, unless otherwise agreed in writing between DNV and the client. 104 All documentation for verification shall be forwarded to DNV in electronic form. DNV may require drawings to be forwarded in hard copy form. 105 DNV assumes that the verification of each documentation package consists of one initial document review and one follow-up review after changes have been implemented to comply with DNV comments. No major changes of methods and other provisions between the first time review and the follow-up review are accounted for in this review set-up. G 200 Deliverables and Schedule 201 The deliverables by DNV must be agreed in detail between the client and DNV as part of the contract. In general the DNV Project Certificate is issued when all of the required statements of compliance according to the DNV Project Certification System have been issued. 202 Each certification phase for a considered element can be verified independently according to the DNV Project Certification System and will be completed with the issue of a statement of compliance for that element. However, successful completion of preceding phases whose completion is a prerequisite for the phase in question is required. For example, prior to verification of the Manufacturing phase for the tower and the substructure, the Design Basis phase and the Design phase for these elements must both be completed and verified. 203 During the verification of documentation DNV provides the following deliverables: DNV review letters and verification comments will be issued during the review process to state progress of reviews including any red flags and forecast to completion. These review letters will be issued in electronic form and delivered by to the client. DNV Technical Report(s) will be issued to document DNV s verification work. These reports will be delivered in a hard copy (paper) as well as electronically as a pdf-file. 204 For surveys during manufacturing, transportation, installation and commissioning as well as in service, DNV will report critical findings immediately after the survey to the client. DNV will issue survey reports to the client and the frequency of these shall be agreed with the client (for example daily, weekly or monthly). The report will describe the extent of the survey including findings, nonconformities and possible recommendations. The report will be issued in electronic form and sent by to the client. 205 Final DNV Design Verification Reports and Letters and corresponding Statements of Compliance will be issued to the client upon completion of the project tasks. The documentation will be delivered in a hard copy (paper) as well as electronically as a pdf-file. In the event that a full compliance is not obtained for all issues, the deliverables will depend on the character of the lack of compliance. Three deliverable options are available: No outstanding issues. A Statement of Compliance with an accompanying DNV Technical Report will be

18 Sec.2 Page 18 issued. In the case of certification to the IEC system, an IEC conformity statement will be issued. A few outstanding less critical issues. A Statement of Compliance will be issued with the outstanding issues listed in the Statement of Compliance. Specific description of the outstanding issues will be given in the accompanying DNV Technical Report. As outstanding issues become closed, updated Statements of Compliance can be issued. Major outstanding issues, referred to as conditions. A Statement of Compliance will not be issued. DNV will deliver the DNV Technical Report that would normally accompany the Statement of Compliance for the relevant elements or phases. The DNV Technical Report will pinpoint the outstanding issues whose rectification is required before a Statement of Compliance can be issued. 206 After completion of Phases I through V for the wind turbine and the support structure, or alternatively for the substation topside and the support structure, the DNV Project Certificate will be issued. The Project Certificate will be delivered in a hard copy (paper) as well as electronically as a pdf-file. 207 An updated DNV Project Certificate will be issued on the basis of successful periodical in-service surveys. The updated DNV Project Certificate will be delivered in a hard copy (paper) and electronically as a pdf-file. 208 DNV will make an effort to comply with the overall time schedule of the certification and verification activities. Final timeframes shall be discussed and agreed between the client, DNV, consultants and suppliers before commencement of the work. Guidance note: In planning the certification schedule it may be assumed that the turn-around time for review comments is in the order of 10 to 15 working days when the documentation is delivered according to the agreed time schedule. A typical duration of DNV s independent analysis and structural strength analysis is 20 to 25 working days. ---e-n-d---of---g-u-i-d-a-n-c-e---n-o-t-e--- H. Combination of Codes and Standards H 100 General 101 DNV certification to internationally recognized standards replacing or supplementing DNV-OS-J101 and DNV-OS-J201 shall follow the principles described in this OSS. Wherever combinations of such standards and external criteria are used, the exact terms of reference and documents to be issued shall be agreed at the beginning of the project and shall be specified in detail in the design basis. 102 The application of standards other than DNV standards does not allow for a reduction of the target safety as described in the safety philosophy sections of DNV-OS-J101 and DNV-OS-J201. DNV reserves the right to call for additional requirements to cover issues essential to the certification process and not covered by the standards in question. 103 It is strongly recommended not to combine standards from different standard systems due to the possible differences in the underlying safety philosophies of the different standard systems. In case standards are combined, caution must be exercised and the choice of standards is subject to acceptance by DNV, even if the standards belong to the same standard system. Guidance note: Within a particular standard, aspects such as requirements for partial safety factors for calculation of design load and design resistance are normally mutually balanced to give an overall acceptable safety level. In another standard with the same overall acceptable safety level, the requirements for the safety factors may have been balanced differently. Picking requirements for load factor from one standard and material factor from another can therefore easily result in unpredictable, and possibly too low, safety levels. ---e-n-d---of---g-u-i-d-a-n-c-e---n-o-t-e---

19 Sec.3 Page 19 SECTION 3 DETAILED SERVICE DESCRIPTION: WIND TURBINE AND SUPPORT STRUCTURE A. Introduction A 100 Objective 101 This section provides the details of DNV s verification activities for each of the phases of the DNV Project Certification System for the asset that consists of the wind turbines and their support structures. B. Phase I: Verification of Design Basis B 100 General 101 The purpose of the verification of the Design Basis is to evaluate if the site conditions and the basis for design including general specifications, criteria, parameters, design approach and other assumptions relevant for design are properly established and documented and that this design basis is sufficient for a safe design and implementation of the project. 102 Unless otherwise agreed, the verification activities are to DNV s offshore standard DNV-OS-J101, which is in compliance with the IEC system. 103 A Design Basis shall be provided to DNV. This design basis shall include documentation of the following: a) site conditions b) codes, standards and requirements c) design criteria d) transport, installation and commissioning requirements e) operation and maintenance requirements f) wind turbine type. The Design Basis identifies the basic assumptions, specification, methods and requirements for the project design. In the case of the project being implemented as a multi-contract project, the design of elements, such as the wind turbine and the support structure, may be carried out by different parties. In such cases the Design Basis forms an essential tool with a view to ensuring, documenting and verifying the safety of the total system and consistency between the different project parts. It is strongly recommended that the Design Basis is developed as an integrated document to be applied for all parts. If the development of the Design Basis is divided between suppliers of parts of the project, the design basis for each part shall contain all information of relevance for the design of that part. In the case of multi-contracting, the design basis may comprise three parts that together form the Design Basis for the project: 1) Site conditions and general requirements relating to (a) through (e) 2) Wind turbine specific requirements relating to (b) through (f), including definition of design load cases and design wind parameters, load factors and turbine design methodology 3) Structure-specific requirements relating to (b) through (e), including interpretation of geotechnical and environmental (metocean) data for design, specification of design methodology including principles, procedure, materials and requirements for Installation and Commissioning and for Operation and Maintenance Typically DNV carries out the work for Part A for the project owner, Part B for the wind turbine supplier and Part C for the support structure contractor. The wind turbine type certificate is not needed in the Design Basis phase, but in the Design phase, for which reason the client s obligations and DNV s services related to the wind turbine type are given in Subsection 3B for the Design phase. 104 DNV will verify the Design Basis for compliance with DNV-OS-J101 and other codes and standards, identified in the Design Basis. Following a successful completion of the verification of the design basis, DNV will issue a statement of compliance.

20 Sec.3 Page 20 B 200 Site conditions 201 DNV will evaluate the establishment of site conditions detailed in DNV-OS-J101, IEC and IEC based on reported data and/or applicable standards or methods valid for the site. The following site conditions shall be addressed and will be subject to verification: wind conditions wave conditions weather windows soil conditions earthquake conditions other environmental conditions electrical power network conditions. 202 For measured data DNV will assess principles and methods for: data acquisition statistical methods applied establishment of design parameters. 203 The metocean conditions provided may be derived from site-specific measurements supported by hindcasts. Site-specific measurements shall when possible be correlated with data from a nearby location for which long term measurements exist. The monitoring period for the site-specific measurements shall be sufficient to obtain reliable data for design. The site-specific measurements shall be carried out and documented as required in DNV-OS-J101 unless a conservative approach is adopted. Such an approach may utilize the uniform conditions at sea together with hindcast models. Independent analysis for selected parameters may be carried out by DNV, based on the environmental and geotechnical data provided. 204 Measurements of the site conditions shall either be carried out by a testing laboratory accredited to ISO/ IEC or shall be subject to approval by DNV on the basis of an evaluation of the quality and reliability of the measurements. Such an evaluation will cover the following issues: test and calibration methods equipment measurement traceability assurance of the quality of test and calibration results reporting of the results. The geotechnical site investigation and laboratory testing are assumed to be carried out by companies with relevant experience from similar work. The quality of the soil investigation and the test results shall fulfil the requirements given in Eurocode 7 Part 2. All parts of ISO/IEC may not necessarily apply to the geotechnical field and laboratory work. In all cases, a description of all test procedures and relevant standards shall be presented. 205 DNV will verify that relevant reports properly document the site conditions. 206 DNV will assess the interpretation of the site conditions and the identification of the design parameters describing the site conditions to be used for design of the wind turbine, support structure and other installations. Design parameters representing the following conditions shall be included: wind climate wave climate correlation between relevant parameters such as wind, waves and current current water level ice water depth seabed topography geotechnical data other site conditions, such as seismicity, lightning, salinity, temperature, spray ice, marine growth, air density, traffic, disposed matters, pipelines and cables electrical network conditions. 207 The verification of the geotechnical design basis will focus on: extent, quality and relevance of the soil investigations derivation of soil parameters from the soil investigations.