Feasibility of Offshore Wind Power in the South Atlantic Bight Bill Bulpitt, Susan Stewart, Mary Hallisey Hunt Georgia Tech Strategic Energy Institute Southeastern Energy Society November 20, 2006

Background NSF Funded InfinitEnergy: A Coastal Georgia Partnership for Innovation –Search for alternative energy options to stimulate economic opportunities for Coastal Georgia region. Strategic energy technology assessments Determine potential for implementation Initial assessments of offshore wind potential in coastal Georgia merited further study Approached local utility to perform a detailed conceptual design study for an offshore wind farm

South Atlantic Bight Wind Resource Bight definition: –Long gradual bend or recess in coastline forming large open bay. –Describes coastal ocean between South Carolina and Florida. 140 km wide continental shelf Off of Georgia’s coast alone: –< 20m deep: ~8,000 sq.km –< 30m deep: ~12,800 sq.km

South Atlantic Bight Wind Resource (continued) Rare offshore wind data available: –50 m high anemometer –Online since June 1999 (nearly 7 years) –27 m deep water, 60 km offshore –6-minute data averages

Grays Reef Buoy R2 Tower Savannah Light Tower

R2 Tower Annual Average Wind Speeds

Average Annual Wind Speed Comparisons at 50 m

R2 Tower Monthly Average Wind Power Density (W/m 2 )

Wind Farm Conceptual Design Study Working with Southern Company on a detailed feasibility study of an offshore wind farm in Coastal Georgia. Teams incorporating both entities working on project tasks. Interaction with State, DOE,MMS, turbine vendors, and environmental organizations throughout study

Update on Project Tasks Wind Turbine Technology Review Turbine Foundation and Platform Options Selection of Offshore Sites/Interconnection Points Submarine Cabling Requirements South Atlantic Bight Benefits & Concerns –Environmental and other issues

Wind Turbine Technology 3 major offshore wind turbine vendors –Others have not “weatherized” products for this environment. –Visited vendors’ projects in Europe Discussions with vendor sales reps

Arklow

Project Statistics Turbines3.6MW x 7 Dept of piles35-45m Weight of piles280tonne (5m diameter) Weight of turbines290tonne Blades50.5m, 15tonne each Nacelle/Hub height73.5M Rotational speed8.5 – 15 rpm Distance offshore 10km Onshore cable5km Voltage 38kV distribution connected Rotor diameter 104m > soccer pitch area 25MW serves 16,000 households (Irish) Sandbank 24 miles long & 2.5 wide, depths m Largest commercially operating turbines installed to date Largest consented offshore site todate Source: McAdam

Scroby Sands

Country: United Kingdom Location: East Anglian Coast, 3km east of Great Yarmouth Total Capacity: 60 MW Number of Turbines: 30 Distance to Shore: 2.5 km Depth: 4-8 m Capital Costs: about 110 million Euro Status: Built Construction Date: 2003 Manufacturer: Vestas Total Capacity: 2 MW Turbine-type: V m diameter/ 60m hubheight Mean Windspeed: 7.5 m/s Windfarm Developer: E.ON UK

Horns Rev

Country: Denmark Location: West Coast Total Capacity: 160 MW Number of Turbines: 80 Distance to Shore: km Depth: 6-12 m Capital Costs: 270 million Euro Status: Operational Construction Date: 2002 Manufacturer: Vestas Total Capacity: 2 MW Turbine-type: V m diameter / 70m hubheight Mean Windspeed: 9.7 m/s Annual Energy output: 600 GWh Windfarm Developer: Elsam

Wind Turbine Technology (continued) Sellers Market –Demand for turbines high in Europe & Asia due to Kyoto Protocol and other promotional programs. –May be hard to obtain equipment for use in U.S. before –Cost information difficult to acquire from vendors They require a review in great detail of wind farm potential PTC “on again – off again” history not helpful.

Wind Turbine Technology (continued) Selection of a unit depends on best economics (power output for the cost) for the given wind resource. –Power output calculated from vendor power curves using R2 data extrapolated to 80 m.

Annual Capacity Factor Using Three Different Wind Turbines

Turbine Foundation and Platform Options From site visits, monopile support preferable –Steel tube 4-5 m diameter driven m into ocean floor –Water depth < 20 m Most expertise resides in Europe, as does the necessary equipment R2 Tower wave characteristics: –Significant wave height = 1.16 m –Maximum wave height = 6.3 m

Selection of Offshore Sites Interconnection Points Geographical consistency of wind resource Substation/landfall considerations: –Grid interconnection access points Proximity to coast Operating voltage Expansion availability Accessibility to beach for access –Shipping lanes –Cabling distance to shore –Cable landfall environmental impact

Economics

Submarine Cabling Requirements Trench for cable: –Prepared with water jet Sand settles over top after cable is laid –Depth of trench important to prevent damage from anchors and trawlers Georgia specific: –Submerged barrier islands –Sand filled channels (former rivers) –Shifting sands

South Atlantic Bight Benefits & Concerns Many benefits and concerns are more specific to South Atlantic Bight Region: –Environmental Issues Migratory pathways and habitats for –Avian species –Right whales ( critical habitat – only known calving ground) –Sea turtles

South Atlantic Bight Benefits & Concerns (continued) –(cont.) Environmental Issues Warm weather –Lightning strikes –Hurricanes »Technology developments »Statistical studies

South Atlantic Bight Benefits & Concerns (continued) –(cont.) Environmental Issues Fisheries –May create an area closed to fishing –Could help increase fish populations Hard bottom substrates –Could be extended via wind farm foundations and scour protection »Creating larger habitat for existing species.

South Atlantic Bight Benefits & Concerns (continued) –Other Issues Coexistence with military installations Hydrography and coastal effects –Submerged barrier islands Community acceptance SocioEconomics Viewshed –Unpopulated stretches of coastline

Bringing ‘Offshore’ Wind Energy into the Mainstream Need a pathway for development –Will vary by region due to different: Wind Resources Geography Environmental Issues Permitting Issues Coastal population density