OFFSHORE WIND ACCELERATOR (OWA) Access Competition. Competition Overview and Technical Specification

Transcription

1 OFFSHORE WIND ACCELERATOR (OWA) Access Competition Competition Overview and Technical Specification In partnership with In collaboration with Supported by Version 1.0. Wednesday 29 September Offshore Wind Accelerator - Access Competition Page 1 of 21

2 1. Competition objectives 1.1. The design competition The Carbon Trust s Offshore Wind Accelerator (OWA) has launched the OWA Access Competition to find and fund the development of innovative solutions to a specific challenge that the next generation of far-offshore wind farms will face: safely transferring personnel and equipment from in-field vessels to and from the wind turbines for the purpose of carrying out operations and maintenance (O&M) activities The challenge Today s offshore wind farms typically comprise 30 to 200 turbines and are located less than 20 km from shore, in benign metocean conditions. Next generation offshore wind farms to be constructed from 2014 will have up to 2,500 turbines and will be located up to 300 km offshore, in more challenging metocean conditions. New technology will therefore be required to safely, reliably and cost-effectively provide access to the turbines for planned and unscheduled maintenance activities. It is expected that new strategies will also be employed for O&M. For example, rather than using vessels to transport personnel directly from ports to turbines, infield bases or mother-ships accommodating maintenance personnel may be used with smaller daughter craft (equipped with transfer systems) to move personnel and equipment to and from the turbines. The purpose of this competition is to identify and develop the necessary technologies for accessing far-offshore wind turbines, focussing on: 1) Transfer systems Systems to transfer personnel and equipment from vessel to turbine; 2) Vessels Vessels for transporting personnel and equipment from permanent bases or mother-ships to turbines, incorporating a transfer system; 3) Launch and recovery systems Systems fitted to permanent bases or mother-ships for launching and recovering daughter-vessels from the sea The prize The successful applicants to the competition will benefit in the following ways: - Funding of up to 100,000 GBP per concept to support the design and development of the successful concepts. - Potentially more than a million GBP of funding to take the concepts to fullscale demonstration. - The opportunity to work with eight leading offshore wind developers with licences to develop 30 GW of offshore wind capacity in UK waters (representing 60% of current licensed UK capacity). Offshore Wind Accelerator - Access Competition Page 2 of 21

3 1.4. The problem (illustration) Today s offshore wind farms Wind farms: up to 20 km from shore, shallow waters, 30 to 200 turbines. Metocean conditions: up to 1.5 m significant wave height. Foundations: Predominantly monopiles. Access: from shore via work boats and personnel stepping across onto ladders. Future offshore wind farms Wind farms: up to 300 km from shore, deeper waters, 200 to 2,500 turbines. Metocean conditions: above 3 m significant wave height. Foundations: Monopiles, jackets, gravity bases and piled tripods. Access: from in-field bases or mother-ships via daughter-craft equipped with new safer transfer systems. Offshore Wind Accelerator - Access Competition Page 3 of 21

4 Table of contents 1. Competition objectives The design competition The challenge The prize The problem (illustration) Introduction The engineering challenge The economic opportunity The Carbon Trust s Offshore Wind Accelerator The OWA Parties Aims and objectives of the competition Current access systems and practice Current site locations and scale Current foundation types Current transfer systems Current vessel types Current launch and recovery systems Future access systems and practices Wind farm locations Wind farm layout and scale Reference wind farm Environmental conditions for reference wind farm Reference turbine type Reference foundation concepts Drivers for access Maintenance Overview - Defining Access Maintenance: type, frequency and loads Types of solutions required Types of solutions out of scope Access Competition details Key information Dates Competition entries Intellectual property and confidentiality Evaluation criteria and weighting Benefits to participants and prizes for winners Information for competition entrants Appendix A: Foundation concepts to be considered Monopile Asymmetric tripod suction pile Inward battered jacket Large concrete gravity base Suction bucket monopile Jacket structure Offshore Wind Accelerator - Access Competition Page 4 of 21

5 2. Introduction 2.1. The engineering challenge The UK is the World s largest offshore wind market, and is expected to remain so for the next 10 years. To meet the European Union s 15% renewable energy target for the UK, as much as 40% of electricity production will need to come from renewables by Currently, 5% of electricity comes from renewables, so an eight-fold increase is required to achieve this target. Mass deployment of offshore wind will be necessary - it has the potential to supply 25% of the UK s electricity by Next generation wind farms will be larger, further from shore, installed in deeper water and in harsher metocean conditions than before. It is estimated that as many as 6,000 turbines in the UK and 15,000 globally will be installed over the next decade. The structures are large, measuring 220 m from the sea bed to the tip of the blade. At an average distance of 65 km from shore, but extending as far as 300 km from the coast, wind farms will be operating in a harsh marine environment. Installation and servicing of these turbines will be challenging The economic opportunity To meet the challenge, there will be a market for a new generation of innovative solutions. It is estimated that by 2020 global investments of up to 2.5bn GBP will be required to build and deliver the mother-ships, in-field vessels and transfer systems needed to perform installation and O&M activities. Research conducted by the Carbon Trust shows that the investments in access systems in the UK alone could be worth up to 1bn GBP by The total offshore wind industry in the UK could create as many as 70,000 new jobs, reduce carbon emissions by 14% and generate revenues of up to 8bn GBP annually The Carbon Trust s Offshore Wind Accelerator The Carbon Trust is an independent company backed by the UK Government with the mission to accelerate the move to a low carbon economy. In October 2008, the Carbon Trust launched a major Technology Accelerator focussed on reducing the cost of energy from offshore wind by 10%, concentrating on four research areas: Foundations, Wake Effects, Electrical Systems and Access, the research area of focus for this competition. The Offshore Wind Accelerator (OWA) is funding research, development and demonstration projects to unlock technological barriers to advance the industry. The initiative is co-funded by major European energy companies (the OWA Parties ). Details of this can be found on the Carbon Trust s web site. Offshore Wind Accelerator - Access Competition Page 5 of 21

6 2.4. The OWA Parties The Offshore Wind Accelerator is a unique partnership initiated by the Carbon Trust co-funded and executed in collaboration with eight international energy companies representing 30 GW of licensed wind generation capacity in UK waters. The Carbon Trust s partners for the OWA are: Dong Energy, the leading Danish offshore wind farm developer with over 20 years experience. Click here for website E.ON is one of the world's largest investor-owned power and gas companies. Click here for website Mainstream Renewable Power, founded by Dr. Eddie O Connor and Fintan Whelan, the former CEO and CFO of Airtricity. Click here for website RWE Innogy, Europe-wide renewables business arm of the German RWE group. Click here for website ScottishPower Renewables, the UK s largest onshore wind farm developer. Click here for website SSE Renewables the renewable energy development division of Scottish and Southern Energy. Click here for website Statoil is an international energy company with over 35 years experience on the Norwegian continental shelf, today with operations worldwide. Click here for website Statkraft, Europe s largest renewable energy company. Click here for website Offshore Wind Accelerator - Access Competition Page 6 of 21

7 2.5. Aims and objectives of the competition This open competition seeks to identify and support the development of new access systems to dramatically improve the availability of wind turbines by allowing safe transfer of personnel and equipment from vessels to turbines in far-offshore, harsh metocean conditions. We welcome competition entries for novel designs to address the following technology needs: 1) Transfer systems systems designed for transferring personnel, with an acceptable level of risk, their tools and equipment to and from an in-field vessel or platform to and from an offshore wind turbine structure; 2) Vessels in-field vessels for the transfer of personnel and equipment to and from a fixed or floating in-field platform (offshore platform, jack-up vessel and/or mother-ship) to and from a wind turbine foundation; 3) Launch and recovery systems systems which will allow daughter craft to be safely launched and recovered from the sea, from a fixed in-field platform or mother-ship. 3. Current access systems and practice 3.1. Current site locations and scale The vast majority of offshore wind farms in the UK are up to 20 km from shore and in relatively shallow waters - depths vary between 5 and 30 m. Most wind farms have between 30 and 200 turbines. Each turbine has a rated capacity of 3 to 5 MW and the rotor diameters range between 90 and 126 m. For further details please visit the following websites: Current foundation types The most common foundation type used is the monopile, a steel tube supporting the wind turbine, fitted onto a transition piece which is grouted to a tubular pile driven into the seabed. For further details see Appendix A (Section 6, page 18) Current transfer systems Vessels commonly travel directly from shore to the wind farm and they thrust-in to the boat fenders on the foundation structure allowing personnel to step directly onto a vertical ladder. An illustration of a current transfer mechanism is given in Figure 1. A combination of simple fit-for-purpose vessels, gangways, vertical steel ladders, safety lanyards and work-platform-mounted davits are employed for personnel and equipment to safely access and disembark from an offshore foundation structure. Offshore Wind Accelerator - Access Competition Page 7 of 21

8 Figure 1 - Illustration of an example current access system. These access methods cannot be used in more challenging sea conditions, as the transfer vessel has difficulty thrusting into the boat bumpers, either because of excessive movement or because the direction of the prevailing weather is not suitable for the access location on the turbine. Some offshore locations utilise winched helicopter access directly to the turbine nacelle as well as marine access. It should be noted that helicopter access is not in the scope of this competition Current vessel types Vessels range in size from 10 to 30 m in length, have mono-hull or catamaran hull forms, travel at up to knots and can allow access in certain conditions, up to 1.5 m significant wave height. Some are fitted with simple gangways, have protruding bow structures or have bows shaped to align themselves with the boat bumpers to allow effective personnel transfers Current launch and recovery systems Wind farms require a short-duration high-speed point-to-point type capability to transfer personnel from on-shore bases onto the wind turbines. It is unlikely that these vessels types will be suitable to serve the needs of future far-offshore wind farms. Launch and recovery systems for daughter craft are not commonly used on today s offshore wind farms. Offshore Wind Accelerator - Access Competition Page 8 of 21

9 4. Future access systems and practices 4.1. Wind farm locations This competition focuses principally on UK Round 3 sites, depicted in Figure 2. Relative to today s offshore wind farms, the Round 3 sites are further offshore, exposed to more changeable and onerous environmental conditions, require longer transfer times to reach, and are likely to require vessels to operate on-site for much longer. Maintenance crew and equipment capacities, comfort, range and emergency capability become much more important vessel characteristics as operations become more remote. Figure 2 - Illustration of Round 3 locations. The UK s offshore wind farm locations are shown on the Crown Estate website: Wind farm layout and scale The Round 3 offshore wind farms are up to 300 km from shore, in water depths between 15 m and 70 m. The size of each development will vary from 600 MW to potentially over 9 GW, each incorporating between 200 and 2,500 turbines. Offshore Wind Accelerator - Access Competition Page 9 of 21

10 4.3. Reference wind farm Wind farm parameters vary from site to site; therefore, for the purpose of this competition a reference site has been developed and shall be used as the basis for the assessment of the solutions put forward. The larger wind sites may be subdivided into smaller maintenance areas. Each maintenance area may contain a manned station and/or transformer platform, or a mother-ship from which operations may be based (see Figure 3). The key parameters of the reference wind farm are summarised in Table 1 and illustrated in Figure 4. Table 1 - Summary of reference wind farm key parameters. Number of wind turbines per service area 200 Wind turbines 5 MW Distance between each wind turbine 1 km Average Water Depth 45 m Distance from port to wind farm up to 300 km Area (foot-print) of wind farm (N-S, E-W) 20 km x 8 km Shape of the wind farm See Figure 4 Figure 3 - Illustration of mother-ship / daughter-craft approach. Offshore Wind Accelerator - Access Competition Page 10 of 21

11 Figure 4 - Illustration of the reference wind farm Environmental conditions for reference wind farm Metocean conditions for the reference site are described in Table 2. Figure 6 shows the cumulative frequency distribution of significant wave heights over a typical year. Table 2 - Summary of the environmental conditions for the reference site. Tidal range up to 5 m Current speed up to 3 knots Wind speed up to 30 knots Wind direction variable Wave period up to 25 s Wave direction variable Significant wave height (H S or H 1/3 ) is defined as the average height (trough to crest) of the highest one-third waves in a wave spectrum recorded over a period of time. For the purpose of this competition the maximum wave height (H Max ) can be calculated using this formula: H Max = 1.86 x H S. Offshore Wind Accelerator - Access Competition Page 11 of 21

12 Figure 5 - Illustration of nomenclature used. Figure 6 - Cumulative frequency of significant wave height in an average year. Offshore Wind Accelerator - Access Competition Page 12 of 21

13 4.5. Reference turbine type The typical wind turbine for future offshore wind projects will likely be 5 MW or larger. Key characteristics and dimensions of a 5 MW machine are given in Table 3. Figure 7 illustrates wind turbine nomenclature. Table 3 - Main parameters of the reference wind turbine. Capacity 5 MW Rotor Diameter 126 m Foundation tower interface level relative to 20 m LAT (see Figure 5 for definition) Hub height above foundation interface 82.5 m Tower diameter, bottom 6 m Figure 7 - Illustration of an offshore wind turbine. For further details, please see the following links: Reference foundation concepts Round 3 and far-offshore wind farm projects will require new foundation designs suitable for deeper waters. The OWA is supporting the development of new Offshore Wind Accelerator - Access Competition Page 13 of 21

14 foundation concepts and the proposed access systems should work with as many of these as possible as well as conventional monopiles. Simple arrangement details for the next generation foundation concepts are included in Appendix A (see Section 6, page 18) Drivers for access Maintenance Overview - Defining Access Modern onshore wind turbines are designed to have one or two planned maintenance checks each year. This is also the target for offshore wind turbines, with increasingly advanced control and monitoring systems being installed to allow the operator to gain in-service data which can often pre-empt problems. Typically unplanned stoppages occur every 1 to 3 months on turbines in serial productions. These stoppages are most frequently due to sensor, wiring and control system faults. However, unplanned maintenance costs can also be attributed to gearboxes, generators and blade repair and replacement. Availability, or the percentage of time that turbines are without fault and therefore available to operate are generally warranted to 97% onshore. In contrast, some of the existing offshore wind farms are experiencing availability in the order of 90%. This means that for every 100 wind turbines up to ten may need some type of restart or repair and most of these restarts or repairs would require access to the machine Maintenance: type, frequency and loads Access needs are driven by the type of maintenance and repairs. For example, where major repairs or replacement of equipment are necessary large vessels with suitable stability, lifting equipment capacity and reach would be required. However, you would not use this type of vessel for routine maintenance. Table 4 - Summary of typical turbine maintenance access requirements. Unplanned Planned Activity Category 1 Manual restart Category 2 Minor repairs Category 3 Major repairs Planned maintenance % of all According to 70% 27% 3% operations* O&M plan Number of people Typical 2-4 days/yr A few hours 1 day Several days duration per machine Purpose Reset the turbine controller Fix sensors or instrumentatio n failure Repair of turbine components e.g. gearbox; shafts Parts change, lubrication, etc. Weight of tools/parts 25 kg 100 kg 1 tonne 300 kg Tools/parts dimensions - 0.8x0.3x0.3 m 2x1x1.5 m 1x0.5x0.5 m *Indicative percentages from current data, these are likely to change in the future Table 4 shows the main categories of maintenance and repair for offshore wind turbines, together with descriptions of typical activities undertaken within each category. Entrants for the competition shall cover at least one of the categories. Offshore Wind Accelerator - Access Competition Page 14 of 21

15 4.8. Types of solutions required This competition is focussed on finding, supporting and developing concepts that provide solutions to at least one of the following problems: 1) Transfer systems - A mechanism to safely and reliably transfer between a vessel and a wind turbine foundation structure (i.e. work platform) for the transfer of maintenance personnel and tools as described in Table 4; 2) Vessels - A marine concept that has the necessary dynamic performance, stability (motion range), operating range and endurance to operate as an: a. In-farm vessel for personnel and equipment transfer; b. In-farm mother-ship. 3) Launch and Recovery Systems - A mechanism to safely and reliably launch and recover an in-farm access and personnel transfer vessel to: a. A fixed platform located in the wind farm; b. A mother-ship operating in the wind farm; c. A temporary fixed vessel, e.g. jack-up, which may be temporarily operating in the wind farm. 4) Integrated solution - Incorporates part or all of the above Types of solutions out of scope This competition focuses on access to the work platform. Note that the objective is for personnel and equipment to be transferred to both the turbine base and nacelle. Novel solutions providing direct nacelle access will therefore be considered. Helicopters are not in the scope of this competition. 5. Access Competition details 5.1. Key information All the information relevant to the competition is available on the Access Competition s website, at the following address: Dates The competition will close on Friday, 26 November 2010 at 17:00 GMT. Winners of the competition will be announced in February The Carbon Trust will then enter into a contract with the successful applicants under the Terms and Conditions included on the website Competition entries Competition entries will propose solutions to one or more of the access challenges identified by the Carbon Trust: 1) Transfer systems; 2) Vessels; 3) Launch and recovery systems; 4) Integrated systems (i.e. transfer system with vessel or Launch and recovery system with vessel). Offshore Wind Accelerator - Access Competition Page 15 of 21

16 Competition entrants can submit multiple applications for the categories above using the submission form. However, the OWA will only consider one concept application per form. The competition welcomes entries from all industries and from all over the world. Entrants do not have to be experts in wind turbines, offshore wind turbines or in the wind energy sector, to enter - or to win. Whatever the sector, this open competition is an opportunity for entrants to apply their expertise to one of the most exciting and fastest growing markets today and for the future Intellectual property and confidentiality It is the intention of the Carbon Trust and the OWA parties that a confidential and intellectually safe environment be created by the competition where technology developers will feel free to share their ideas and concepts without fear of plagiarism or impact on their secrecy. As a result the Carbon Trust and the OWA parties guarantee that the Intellectual Property (IP) included in submissions to the OWA Access Competition and IP that will be developed during any subsequent phase is and will remain property of the provider, will be treated in confidence and exclusively for the purpose of assessing and evaluating the competition entry. For more details, please refer to the following documents (available on the Access Competition website Summary of IP Provisions (PDF); - Terms and Conditions (PDF) Evaluation criteria and weighting Submissions will be evaluated according to the following criteria and weighting: - Potential to improve availability (40%); - Potential to improve safety (40%); - Expected capital and operating costs (20%) Benefits to participants and prizes for winners The successful applicants of the competition will benefit in the following ways: - Funding of up to 100,000 GBP per concept to support the design and development of the successful concepts. - Potentially more than a million GBP of funding to take the concepts to fullscale demonstration. - The opportunity to work with eight leading offshore wind developers with licences to develop 30 GW of offshore wind capacity in UK waters (representing 60% of today s licensed UK capacity) Information for competition entrants Competition entrants should note that this document does not constitute an offer to contract with the Carbon Trust. It only represents a definition of specific requirements and an invitation to submit a proposal addressing these requirements. Issuance of this invitation and the subsequent receipt and evaluation of the proposals by the Carbon Trust does not commit the Carbon Trust to enter into contract with any competition entrants. Competition entrants should also note that: Offshore Wind Accelerator - Access Competition Page 16 of 21

17 - unless a competition entrant makes a formal statement to the contrary, the Carbon Trust reserves the right to accept any part of their proposal without accepting the remainder; - the costs of submitting a proposal are the full responsibility of the entrant The information contained here, in the Technical Specification and in any documents or information it refers to or incorporates (the Disclosed Information ) has been prepared to assist interested parties to decide whether to submit a proposal. The Disclosed Information is not a recommendation by the Carbon Trust. It does not purport to be all inclusive or include all the information that a competition entrant may require. Neither the Carbon Trust nor any of its directors, employees, agents or advisers makes any representation or warranty (express or implied) as to the accuracy, reasonableness or completeness of the Disclosed Information. All such persons or entities expressly disclaim any and all liability (other than in respect of fraudulent misrepresentation) based on or relating to the Disclosed Information or any subsequent communication. The only information which will have any legal effect and/or upon which any person may rely will be such information (if any) as has been specifically and expressly represented and/or warranted in writing to the successful competition entrant in any written contract that may be entered into with the Carbon Trust. Offshore Wind Accelerator - Access Competition Page 17 of 21

18 6. Appendix A: Foundation concepts to be considered This appendix describes the foundation types to be considered in this competition Monopile Monopile foundation (Figure 8) is to be considered for water depths of up to 20 m. Figure 8 - Illustration of a monopile foundation. Offshore Wind Accelerator - Access Competition Page 18 of 21

19 6.2. Asymmetric tripod suction pile The asymmetric tripod foundation on suction piles was developed by the SPT Offshore & Wood Group (UK/NL) and is shown in Figure 9. Figure 9 - Illustration of an asymmetric tripod suction pile foundation Inward battered jacket The inward battered guide jacket structure shown in Figure 10 was developed by Keystone Engineering (USA) and uses 3 supporting legs angled around a central pile in a twisted jacket (US Patent N. 7,198,453, 7,134,809 & 6,783,305 and related foreign patents; US pending applications and related foreign applications). Figure 10 - Illustration of an inward battered jacket foundation. Offshore Wind Accelerator - Access Competition Page 19 of 21

20 6.4. Large concrete gravity base The large concrete gravity base structure, transported by an unmanned submersible transport and installation barge, was developed by Gifford/BMT/Freyssinet (UK/FR) and is shown in Figure 11. Figure 11 - Illustration of a large concrete gravity base foundation Suction bucket monopile The suction bucket monopile illustrated in Figure 12 is primarily made of steel and uses buoyant installation and delivery. It was developed by MBD Offshore (DK). Figure 12 - Illustration of a suction bucket monopile foundation. Offshore Wind Accelerator - Access Competition Page 20 of 21

21 6.6. Jacket structure A jacket structure foundation type is shown in Figure 13. Figure 13 - Illustration of a jacket structure foundation. Offshore Wind Accelerator - Access Competition Page 21 of 21