Wind Assessment Basics

Transcription

1 Wind Assessment Basics 120 Power curve for Northwind kwh For Island Institute Fall 2013 by Mick Womersley Wind speed in M/S

2 A misspent youth?

3 Essentials of Wind Assessment Turbines are expensive and if you don t put them in a good windy spot, you can waste money: millions of dollars for a big turbine Subjective assessment is not scientifically valid. You may think you have the wind, but you don t know Wind maps are OK, but not great. (I ll show you how to get a goodenough one for free) To really know, instrumental assessment is best. You need to put up an anemometer and vane at the same height as the turbine, on the same site, or better yet, a bank of anemometers at different height intervals, with back-ups in case of failure Computer logging is best. No one can read an anemometer as often as a computer can The industry standard is to record wind speed in meters/second, averaged every ten seconds, over one or two years This is an expensive procedure, done only for the larger more expensive turbines. Smaller turbines can be simply put up on the basis of a wind map and the recommendation of a region-knowledgeable site analyst, monitored for performance (and moved/sold on if need be)

4 Maine has enough wind in some places USDOE Maine wind resource map The majority of Maine is listed as a Class 1 to 2 wind resource area Estimated average wind speed = 5.24 m/s

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8 Frankfort/Prospect, Maine community wind power planning GIS Mick Womersley, Unity College, June 2011 Base data from Maine GIS library, wind data from National Renewable Energy Lab 50 meter high resolution wind data set Discussion: This map uses basic mapping data and GIS software freely available for use. It was made in Q-GIS using basic data from the Maine GIS Library, free access online, as well as wind data from the NREL. It shows the terrain and basic planning features most pertinent to community discussion of wind power proposals in parts of the Maine towns of Frankfort and Prospect. Copies can be made by request for town or public use by calling or ing the author at Unity College. Similar maps can be produced on request for other towns in Maine. WPC 2 Penobscot River (WPC 2) Legend 50 meter AGL Wind Power Class (WPC) contours: First contour: Wind Power Class 1 (0 to 5.6 meters/second) Second: Wind Power Class 2 (5.6 to 6.4 meters/second) Third: Wind Power Class 3, (6.4 to 7 meters/second) Fourth: Wind Power Class 4, (7 to 7.5 meters/second) WPC 2 Mount Waldo WPC 2 WPC 3 WPC 4 20 foot USGS contours Wetland zoning Roads and tax parcels in black, tax parcels not available for some towns

9 Maine Wind Energy Potential Sites so far (public data, Villeneuve, Womersley and FIW) Thorndike Vinalhaven Charleston Oakland UMPI NMCC Sedgewick Mercer Strong Fayette Auburn Lewiston Farmington Old Orchard Beach Peaks Island

10 What you need: Preliminaries A windy site where you expect a turbine is feasible and have completed preliminary surveys: There seems to be good wind Ground is suitable or can be made so: trees, rocks, soils Preliminary tests are done with hand-held equipment Existing wind maps are consulted. A wind mapping program such as WAsP is used to extrapolate potential wind speeds The site owner gives permission, and will likely allow a turbine in the future An idea of potential turbine scale and any siting difficulties to be planned for: neighbors/community objecting, noise, zoning, interference Preliminary cost assessment and funding potential includes free federal and state money, rebates and offset costs

11 What you need: Logistics/training/equipment An appropriate anemometer rig, sized to match potential turbine, may have several sensors, custom or standard Computer logger and home base computers with software, etc Trained safe work crew, up to ten strong backs Safety knowledge and installation skills Lift kit and tools, etc: Personal safety gear, winch, tool kit, crew and freight vehicles, may need off-road Workmen s comp, liability, OSHA, etc Or (newly available), access to existing wind data from a nearby site and a LIDAR machine -- LIDAR and comparative data must run concurrently

12 Typical costs: Equipment: up to $18,000 for 60-meter, six-sensor, twovane rig Lift kit and special tools: up to $6,000 Three long days trained $15/20/hour: $3,000- $6,000 Crew chief, check-ups, maintenance and analysis: $3,000- $5,000 Vehicles, transport, mechanics tools etc: $1,000 Total expenses for one grid scale tower site: up to $35,000 or $40,000 (without paying any commercial profit) Currently, Unity College can do one site/year for the variable costs only ($9,000-$10,000), for a community group or non-profit, and is seeking such a site. Federal grants may be available

13 Please don t ask Why do we have to have a large ugly turbine? Why can t we have one/lots of those nice little turbines? Why not? Laws of physics: square-cube law the power law

14 Going up.

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22 Coming down. (A year later)

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28 The basic system we used, in the testing phase

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33 Data analysis The primary data set, wind speed in ten-second averages, is converted to 10 minute and 60 minute averages, filtered for errors, icing, etc, using NRG Wind Data Retriever NRG reports and charts are produced: Monthly averages, wind rose, etc, to explore the data.txt files are exported of 60 minute and frequency distribution data sets Frequency distribution is matched to the power curve of a specific wind turbine make and model, can be done in MS Excel Adjustment is made for hub height, altitude, air density, etc. Final report includes projections of annual production in WWH or MWH, also possible economic analysis if important parameters are known: Cost of money (interest rates) Turbine costs, O & M, can be several turbines Power sales earnings ( /kwh) Free money, offset costs, etc This is fairly technical work: graduate, or post-graduate training required

34 Mt View Site data: Percent Frequncy of occurance Wind speed frequency intervals in mph

35 Refurbished Northwind 100 on the Mt View site: KHW KHW KWH per wind speed frequency intervals

36 Refurbished Vestas V17 on the Mt View site: KHW KHW KWH per wind speed frequency intervals

37 Fox Islands Wind Farm (Photo Prairie Weather blog

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39 Where we come in: Wind assessment: scientifically measure the wind and assess the power production potential remove (most, not all) doubt as to the economics of a site Community wind mapping Better data for planning, including noise and planning not to have a turbine if that s the best choice Time to get to work?

40 Wish-list! NRG Systems LIDAR