Presentation on theme: "Wind energy resource assessment for offshore sites in the Great Lakes Peter Taylor 1,2, Wensong Weng 1, Jim Salmon 2 1 York University, 2 Zephyr North."— Presentation transcript:
Wind energy resource assessment for offshore sites in the Great Lakes Peter Taylor 1,2, Wensong Weng 1, Jim Salmon 2 1 York University, 2 Zephyr North Canada Contact:
Canadian Wind Atlas, 80-m height average winds
Wind Rose Information ValuesRosesHistogramsTurbine formula Wind Roses at 80m Frequency distribution of wind by sector Latitude = , longitude = Warning: The first column of the wind rose files shows the wind direction computed in degrees starting from the east then rotating counterclockwise --> 0 degree = east, 90 degrees = north. Annual Annual Download the.txtfile forthe wind roseDownload the.txtfile forthe wind rose From Canadian Wind Atlas. 80m, annual wind roses Lake Erie near ClevelandLake Ontario -Wolfe Island Shoals
Cleveland OH Wolfe Island Prince Edward County
Internal Boundary Layers
Weng et al. JWEIA 98,
Long fetches, heights around 100m. PBL model, neutral or stratified With Boundary-layer approximations, and in 2D, we solve the RANS and Continuity equations, together with closure hypotheses for Reynolds stresses and fluxes. Details in Weng et al. JWEIA
Closure hypotheses, TKE and length scale equations Stable Stratification Neutral or Unstable Stratification l b = 40m – 100mζ = z/L
Equilibrium hodographs for different roughness lengths
A typical Southern Ontario onshore flow situation. Neutral stratification. Significant reductions at 80m start about 1 km inland.
Offshore flow: maybe from Toronto over Lake Ontario? Neutral stratification. Note increase at 80m requires fetch > 1 km and equilibrium takes 100 km
Non-Neutral cases City to warm lake. A little less shear in m height range Lake to cool land surface. 80m winds stay a little stronger than in neutral case.
NEWS RELEASE Windstream Energy Wins 300MW Contract to Develop Canada’s First Off- Shore Wind Facility TORONTO, Ontario, April 9, Windstream Wolfe Island Shoals Inc., a subsidiary of Windstream Energy LLC, is pleased to announce that it has been awarded a Feed-in Tariff contract by the Ontario Power Authority to develop Canada’s first offshore wind site. The 300 MW site is located west of Wolfe Island, Ontario on approximately 48,000 acres of shallow water shoals. Windstream Energy was also advised that its ten on-shore projects, totalling 745 MW, have been placed in the Economic Connection Test queue for future review. The first such test is scheduled for the August/September time frame. Ian Baines, President of Windstream Energy commented, “We are extremely excited about the opportunity afforded to us by the government of Ontario and the Ontario Power Authority. The 300MW offshore Wolfe Island site will create hundreds of jobs for the Province of Ontario and the local municipalities. Wolfe Island is one of the windiest areas of the province and has proven local support for wind development. Our project is close to the Lennox Thermal Station, and will offset the use of fossil fuels, by providing power generated by the abundant winds of Lake Ontario.”
WIS Modelling study Aim is to obtain an initial estimate of offshore winds based on data measured at an on-shore site. Use data from 50-m and 80-m masts on Wolfe Island. Model effects of roughness changes assuming a common far upstream flow.
Wind speed variations at various heights upstream of the Merry Farm tower. Distances measured from a location 12.5 km upwind of the tower with z 0 = 0.5m Wind direction: N.Wind speed evolution approaching Merry Farm tower
Wind speed variations at various heights upstream of the BLM4 site. Distances measured from a location 30.8 km upwind with z 0 = 0.5m Wind direction: N.
N wind results U g = 15m/s Methodology is to make the same set of calculations for 16 wind sectors, and then compute mapping factors between winds at the on- shore site to those offshore. Stability and thermal changes could also be taken into account, or at least their impacts could be assessed. Next step is offshore measurement.
GE and Lake Erie Energy Development Corporation Announce Great Lakes Offshore Wind Partnership at AWEA DALLAS - GE and Lake Erie Energy Development Corporation (LEEDCo) of Northern Ohio announced today a long-term partnership beginning with the development of the first fresh water offshore wind farm in the US and involving a broad range of other initiatives. Under the new partnership GE will provide direct-drive wind turbines to LEEDCo's 20 megawatt offshore wind project in the Ohio waters of Lake Erie. The partnership and project is a significant step towards accelerating the deployment of offshore wind in the Great Lakes.
A 3-D model and turbulence length is formulated as in 2-D.
Log 10 z 0 for Cleveland area, lake z 0 =2x10 -4 m, upstream z 0 = 0.05m contours are for log 10 z 0 = -3,-2,-1,0.
3-D model results, 80m wind speed for S flow near Cleveland CRIB site, Geostrophic wind speed 15 ms -1. Upstream wind speed at 80 m with z 0 = 0.05m is approx 10 m/s. Flow slows over the city then slowly accelerates over the lake. Far downwind, the 80m equilibrium speed is close to 13 ms -1 while it is only 9.5 ms -1 at the CRIB site for these South winds. Results for 210 degrees would be similar.
The Toronto Hydro platform, installed in Lake Ontario, May 2010 with ZephIR lidar. Scarborough Bluffs, Toronto
Conclusions Offshore wind farms in the Great Lakes will be in place in shallow areas within a few years. Offshore turbine installation is expensive so a good wind resource is essential, 7 3 = 343, 8 3 = 512, 9 3 = 729. A long over-water fetch is needed before 80-m height winds reach equilibrium, over-water values. For predominant winds from SW the northern half of the lakes have longer fetches over water……..