Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Retrospective: Preliminary Design and Permitting of the Hull Offshore Wind Project J. F. Manwell, Prof. and Director Wind Energy Center (a.k.a Renewable Energy Research Laboratory) University of Massachusetts Amherst May 12, 2011

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Wind Energy in Hull Pemberton/ Windmill Point (Hull Wind I) Landfill (Hull Wind II) Harding Ledge (Proposed Hull Offshore Wind)

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts The Proposed Hull Offshore Wind Project Up to four wind turbines  3-5 MW (295’ - 417’ rotor diameter) (Hull Wind 2: 1.8 MW, 262’ rotor) Installed in vicinity of Harding Ledge MW total generating capacity Energy production (on average) could approach 100% of Hull’s electricity consumption

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Offshore Wind Turbine and Support Structures Some offshore wind turbine support structure options Types suitable for Hull depend on seabed properties

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Project History 2003: First conceived; modeled on Middelgrunden and Samsø (Denmark) –Based on one or more GE 3.6 MW turbines –First filing w/ Army Corps of Engineers –Studies supported by MA Renewable Energy Trust –Wind/desalination study (Bureau of Reclamation) 2008: Certificate from MA EOEEA 2009: Financial study by LaCapra

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Preliminary Siting Constraints In Hull’s waters Suitable for commercial turbines –20-40 ft deep Outside shipping lanes We initially chose these distances: > 1 mile from shore < 2 miles from proposed connection point

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Siting Criteria Minimize impacts –Marine environment –Human activities Fishing, boating, etc… Ship and airplane traffic Transmission line –Allow a feasible landfall –Minimize length Maximize wind speeds Minimize cost of energy

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Wind Resource Assessment Used for: –Energy production estimates –Design of wind turbines and support structures Data from: –Monitoring on Little Brewster island and WBZ towers –Historical data from Boston Harbor and offshore buoys Mathematical projections

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Wind Data Collection Conventional anemometry and LIDAR

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Wind Data Collection Location and data collection: Approx. 2 miles Little Brewster Island Aerial view of Little Brewster Harding Ledge Anemometer LIDAR placed here

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Wave/Current Data Monitoring using a Sontek “acoustic Doppler profiler” (ADP) in vicinity of Harding Ledge Correlations with offshore buoys NDBC Data Buoy Sontek ADP

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts ADP Being Deployed

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Sample Wave Data Storm in mid-April, 2007: Web cam screen shot Typical waves during storm

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Geophysical Studies Bathymetric data Acoustic sub bottom profiles Vibracore soil sampling Sub bottom boring and sampling Magnetic maps Seafloor imaging

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Area of Geophysical Study Off Nantasket Beach: Harding Ledge

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Geophysical Data Collection Obtained with various instruments towed by or located on one or two boats 

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Bathymetric (Water Depth) Data Obtained with echosounder –SyQwest, Inc. HydroBox echosounder Using 8-degree 200-kHz transducer

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Bathymetry

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Acoustic Sub-Bottom Profiling Sound is produced by “boomer”, towed behind boat Sound penetrates soil to various depths; some of it is returned Return signal provides information about soil Used to identify discontinuities in soil characteristics below ocean floor Preliminary to soil borings

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Sub-Bottom Profiling (Deep) Used Applied Acoustics Engineering CAT200 Boomer seismic system Boomer emits sound at a peak frequency of 1125 Hz and a maximum power of dB

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Vibracore Vibracore: method of retrieving undisturbed core samples sub- bottom sediment Samples from relatively close to the sea bed Used here to study electrical cable path

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Sub Bottom Soil Borings Obtain sub bottom soil samples to enable design of support structures Borings go through sediment into rock Typical depth ~50 ft Drilling rig on jack-up barge off Nantasket Beach

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Sample Soil Borings

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Typical Soil Cross Section

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Permitting Environmental Notification Form (ENF) filed Mass. permitting authority has issued certificate specifying certain actions required before final permit can be issued:

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Permitting/Certificate Topics Project Description/Alternatives analysis Permitting/Consistency Green house gas reduction Land alteration/Cumulative impacts Fisheries/Marine resources/Wetlands/Water quality Rare species/Avian/Bat impacts Noise/Visual impacts Historical/Archaeological Construction/Maintenance/Decommissioning Environmental monitoring

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Alternatives Analysis Stay within town boundaries Limited space for land based turbines 1 nautical mile limit for viewshed concerns

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Green House Gas Reduction Study Considered CO 2, NO X and SO2 Method used hour by hour simulation of the energy that would have been produced by the proposed offshore wind farm, resulting in decreased use of conventional power plant Turbines would result in GHG reductions greater than considering only average pollutants per kWh

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Visual Impact: Photo Simulation (view from Clarion Hotel)

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Magnetic Data Acquisition Magnetic data with using high resolution marine magnetometer system – Marine Magnetics, Inc. MiniExplorer For detecting metallic wrecks, ordnance, etc.

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Magnetometer Results Some metal identified but nothing significant

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Side Scan Sonar Sonar emits sound waves Used for identifying underwater surface features, shipwrecks, etc. Device towed behind boat 

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Side Scan Sonar Results No significant artifacts found 

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Archaeological Studies Conclusion: –No evidence of Native American artifacts –No evidence of significant shipwrecks

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Electrical/Cable Route Options Electrical study  –15 MW OK for grid as is Submarine cables transmit power to shore Layout needed for: –Cost estimates –Environmental impact assessments –Interconnection planning Some possible cable routes

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Support Structure/Foundation Study Undertaken by Grontmij Carl Bro (Denmark) Focused on gravity structures Suitable for hard soils Could be fabricated locally

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Typical Fabrication/Installation Fabrication could be done at Quincy shipyard

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Fisheries/Avian Some fisheries studies have been carried out, specifically regarding lobster More studies would be required Avian studies remain to be done

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Economics Capital cost estimates still uncertain, most recently estimated at approx. $60 million Capacity factors expected to be 30-35% Wholesale cost (direct value) of electricity has ranged significantly over last 10 years Cost to produce electricity from offshore wind turbines at present exceeds direct value Multi-purpose project would be needed to make economics work

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Summary Many studies have been undertaken No fatal flaws Site still appears attractive for an offshore wind energy project  –Energy production, research and education More studies needed for permit Detailed cost estimates not yet done Feasible project plan remains to be developed

Mechanical and Industrial EngineeringWind Energy Center University of Massachusetts Electrical System Study showed local network could accept additional 14 MW of turbines