Utility Scale Wind Turbine Design Issues Bruce Bailey, President AWS Truewind, LLC 255 Fuller Road Albany, NY 12203 [email protected] Talk Topics Wind Turbine Components Wind Plant Components Wind Speed vs. Power Production Project Development Steps Agreements Needed To Develop Offshore Wind Energy Wind Turbine Components Composite Blades Gearbox, Generator and Power Electronics Rotor Hub height Diameter 70-90 m 65-80 m nacelle Rotor RPM ~10-20 Tubular Tower Automatic Pitch blade Control steel tower padmount transformer Inverted T-slab foundation foundation Nacelle for 1.65-MW Turbine What’s Inside? Technology Trends Larger Rotors » 80-100 m Higher Ratings » >2 MW on land » >4 MW offshore Taller Towers » 80-100 m Variable Speed Direct Drive » No gearbox Onboard Cranes Climate Packages Wind Plant Components Electrical Substation Wind Turbine Underground electric system and fiber optic communications Service Road Crane Pad 11.5 MW Madison Wind Power Plant Typical Wind Plant Layout On-Site (Residential) Wind Systems 10 kW Wind Turbine TYPICAL SMALL SYSTEM 10 kW (23 ft. Rotor Diameter) Rural Site, 1 Acre or More Connected to Facility Wiring 24 m (80 ft) GuyedTower Produces ~ 13,000 kWh per Year Excess Power Sold to Utility (PURPA) Safety Cummulative Switch Production Meter Either Net Metering or Very Low Power Processing AC Load Buy-Back Rate Unit (Inverter) Center Cost: ~ $45,000 - $60,000 Relationship of Wind Speed to Power Production Rated Speed GE 1.5xle - 1.5 MW 1600 1400 1200 Wind Speed Power Output 1000 kW 800 600 Turbine Output(kW) Turbine 400 200 0 0.0 5.0 10.0 15.0 20.0 25.0 Wind Speed (m /s) Cut-In Speed Cut-Out Speed 1 m/s = 2.24 mph 1 mph = .447 m/s Wind Plant Output & Maintenance Typical capacity factors are 30-40% at good wind sites Wind speeds are above cut-in >85% of the time Turbines are available to generate >97% of time Scheduled maintenance occurs 1-2 times per year ~1 skilled O&M job for every 10 turbines installed Project Development Steps Site Selection Resource Definition Project Design & Engineering Permitting Financing Construction Operations » 3-5 yr period from site selection to commissioning Land Acquisition Rule of thumb - about 50 acres to the MW Usually Lease Agreement Option on the land first (about $3 to $5 per acre?) Much land is currently optioned Lease cost (~ $3000 - $5000 per turbine per year) Can include royalty payment option Agreements Needed By Developer Land acquisition Permits (local zoning & building; state) Tax Payments Turbine Purchase & Warranty Interconnection Power Purchase Financing Maintenance Planning Uncertainties Permitting » visual (NIMBY) » bird & bat studies Transmission » access & capacity constraints » interconnection study queue backlog Schedule Delays » risk of missing incentive deadlines Weather Wind Forecasting Required for scheduling and dispatching of wind plant output in a growing number of energy markets Adds costs to wind plant operations ($0.08-.20/MWh) Reduces ancillary service costs to grid system operator Reduces/eliminates risks of imbalance charges California Independent System Operator Control Room Conclusions • Wind technologies continue to mature and achieve acceptance • Costs are competitive • Optimization of component sizes • New techniques reduce uncertainty in siting and production forecasting • Large majority of public favors wind energy, but wider deployment is triggering NIMBY opposition • Transmission constraints & inconsistent government policies will limit rate of growth .