Virginia Offshore Wind Advanced Technology Demonstration Program and Test Pad Sites Briefing to Virginia Offshore Wind Development Authority Richmond, VA 08 December 2011 George Hagerman VCERC Director of Offshore Wind Research Virginia Tech Advanced Research Institute Jonathan Miles James Madison University Rick Thomas Tiimmons Group
VCERC-Identified Needs for Advanced Technology Demonstration George Hagerman
Virginia Advanced Technology Demonstration Project Characterization Distinguished from private industry projects on Eastern Shore Specifically designed to address research roadmap of VCERC report Project plans and findings will be made public to benefit multiple offshore wind stakeholders, including turbine designers, commercial project developers, and state and federal regulatory agencies Site 1 to measure radar effects and test mitigation technologies Commercially available low wind speed turbine of 2- to 3-MW rated capacity with rotor diameter of 100 m or more In addition to being within range of multiple air traffic control and long-range surveillance radars, also located within range of Wakefield NEXRAD Doppler weather radar Land or pier-based, interconnected behind the meter to customer in northern Suffolk or Portsmouth
Virginia Advanced Technology Demonstration Project Characterization Site 2 to demonstrate novel foundations and installation methods Subscale trial-and-error testing of rapidly installed foundations Shallow, well-protected waters off Newport News Point where vessels and barges can be staged behind wave screen Test turbines for weight and mass distribution; will not be operational and will not be electrically interconnected Site 3 to fully measure turbine-structure-soils response to metocean loading, to observe avian interactions with turbine, and to validate various remote sensing technologies Commercially available, already type-certified offshore wind turbine of 5- to 7-MW rated capacity with rotor diameter of 150 m or more Oceanic environment subject to full force of offshore storm winds and exposed to high swells from tropical storms and hurricanes to southeast CBBT Fourth Island remote sensing range of 3.2 to 4.0 km; also within line of site of sensors on other CBBT islands or at Cape Henry
Stationary ASR and ARSR Installations are of Particular Concern to Virginia Offshore Wind Backup slides show LOS ranges for these six radar installations
Langley AFB 1 st Fighter Wing Concern over Impact on Tactical Radar During VACAPES Training Departure routes Recovery routes Exercise areas
Recognition of 1 to 10 m 2 RCS Targets may be Compromised 80 to 200 NM Away from Projects
Metocean Constraints on Hub-Height Crane Lifts 53 to 76 days 38 to 50 days Maximum sea state conditions for jacking are 1 to 1.5 m significant wave height. Maximum wind speeds for crane lifting to a hub height of 80 or 90 m are 8 m/s for blades and 11 m/s for nacelles. Tables show percentage of time that conditions under these limits occur at the Chesapeake Light Tower, 24 km offshore. Modeling is underway to extrapolate to the commercial lease area, 44 km to 69 km offshore.
Attributes of Novel Foundation-Installation Design Small-diameter legs in multi-pile seafloor template reduce potential for large scour pit. Maritime operation with no crane lifts to hub height. 2004 MERLIN concept shown above has significant wave height limit of 2.5 m, nearly tripling total installation weather window off Virginia Beach to ~350 days per year. Allision-friendly: modeling studies suggest that vessel adrift would slew around surface-piercing monopole as opposed to becoming trapped within surface-piercing trusswork of jacket-type structure.
Allision Risk must be Considered for Foundations to be used in Virginia WEA
Measurements in Oceanic Environment can Verify Metocean Inputs & Turbine-Foundation Response Metocean design environment (for extreme survival and for accumulated fatigue damage) in North Sea is dominated by extra-tropical cyclones, which are large, slow-moving winter storms where wind and wave forces have similar directional alignment. As shown in lower right simulation of force time series on jacket member, aerodynamic damping of rotor greatly reduces structural response to wave loads. Increasing force
Last Published Full-Scale Offshore Measurements were on 2 MW Turbine with 66 m Diameter Rotor 66 m 62 m The Blyth project consists of two Vestas V66 2MW turbines, located ~1km offshore in 9 m mean water depth (6-11 m with tidal variation), installed in late 2000 on rock-socket monopile foundations at a hub height of 62 m.
Economically Viable Turbines for Offshore Mid-Atlantic Projects will be MUCH Larger Nordex and Siemens also have direct-drive 6 MW turbines with 150 m diameter rotor at 90 m Hub Height ALSTOM Power 6 MW with 150 m diameter rotor = 2,945 m 2 swept area per MW VCERC baseline design: Vestas 3 MW with 90 m diameter rotor A B Vestas 3 MW with 112 m diameter rotor = 3,284 m 2 swept area per MW (requires 18% larger rotor swept area for same energy production as direct-drive TG)
Large Tower-Top Motions of Operating Turbines in Hurricane Waves a Fatigue and Durability Concern CUT OUT SPEED Hurricane Irene Waves from SW grew from 9 ft to 16 ft over 12 hours, while winds blowing from E grew from 15 to 30 knots. Turbine cut-out speed of 25 m/s is 48.6 knots.
Need for Validation of Avian Remote Sensing and Observation of Flight Behaviors Around Turbine
CBTT Islands offer Nationally Unique and safe Platform for Trained Observers
Advanced Technology Demonstration Project Site Identification and Study Maps Rick Thomas
Technology Demonstration Site 1 Study Area for Radar Effects Measurement & Mitigation Site IB Site IC Site IA
Technology Demonstration Site 1 Study Area for Radar Effects Measurement & Mitigation
Technology Demonstration Site 2 Study Area for Sub-Scale Foundations and Installation Methods Area deeded to the City of Newport News by the Commonwealth of Virginia Site 2A Site 2B
Technology Demonstration Site 2 Study Area for Sub-Scale Foundations and Installation Methods
Technology Demonstration Site 3 Study Area for Full-Scale Installation and Avian Interaction Site 3 Site 3
Technology Demonstration Site 3 Study Area for Full-Scale Installation and Avian Interaction
Thank You! VCERC Offshore Wind Studies Final Report: www.vcerc.org/report.htm Any questions? Email: hagerman@vt.edu
Back-Up Slides Showing Stationary Radar LOS to 100 m and 250 m Rotor Tip Heights Timmons Group GIS display using data from www.nrdc.org/energy/readgdb.asp
Site 1 ASR Line of Site (LOS) to 100 m High Turbine Rotor Tip
Site 1 ASR Line of Site (LOS) to 250 m High Turbine Rotor Tip
Site 1 ARSR Line of Site (LOS) to 100 m High Turbine Rotor Tip
Site 1 ARSR Line of Site (LOS) to 250 m High Turbine Rotor Tip
Site 1 NEXRAD Line of Site (LOS) to 100 m High Turbine Rotor Tip
Site 1 NEXRAD Line of Site (LOS) to 250 m High Turbine Rotor Tip