Jump to content

Brian Ohrbeck Hansen

WAsP team
  • Posts

    25
  • Joined

  • Last visited

Brian Ohrbeck Hansen's Achievements

  1. Hi Pedro, Please have a look in the WAsP Map Editor's help file regarding "Digital Map Databases" and "Database-Map-Importer". Best regards, Brian
  2. Dear ysga, Horizontal axis wind turbines do of course also "accept" wind from all directions (because they are able to yaw/turn). That aside, the starting point of the WASP analysis is a high-quality wind data set. Wind data should preferably be available as time-series of wind speed and wind direction. The time-series data to be used in a wind climate analysis, should come with some additional information:
- name of data file(s)
- data period
- data format
- observation interval
- averaging period
- calm thresholds (for speed and direction, resp.)
- data discretisation (resolution)
- flag for missing data?
- direction relative to geographic or magnetic north

 In WAsP, the wind analysis can be performed with the Climate Analyst tool (freeware). It includes a comprehensive help file. You can download the WAsP suite installer here: http://www.wasp.dk/Download/WAsP12-Suite-Installer Because the power output of a wind turbine is proportional to some power (> 1) of the wind speed, the precision requirements of wind speed statistics for energy assessments are higher than for most other purposes. Let’s summarise and detail the demands to the data behind the observed wind climate. The quality concept is sub-divided here into accuracy, reliability and representativeness. The first two points – accuracy and reliability – reflect that the sensors should be accurate and remain accurate over the duration of the measurement campaigns. This requires an O&M program if the measurement campaign is longer than 1-2 years. A very important part of performing measurements is the quality assurance (QA) of the data.
 
The representativeness of the data describes how well they can be expected to represent the wind climate at the predicted site. A high recovery rate of course has implications for the necessary instrumental, calibration and service quality. The data used in WAsP should always be seen in the context of the long-term wind climate at the site.

I recommend our WAsP course: http://www.wasp.dk/courses-and-certification Best regards, Brian
  3. Hi Rachel, The capacity factor of a wind farm is the annual energy production (AEP) divided by the theoretical maximum AEP. Capacity factor = AEP / (rated power * 8760 hours per year) See also: http://drømstørre.dk/wp-content/wind/miller/windpower%20web/en/tour/wres/annu.htm#capfac Best regards, Brian
  4. Hi Carriv9, WAsP is for the vertical and horizontal extrapolation of wind climate statistics. Based on an observed wind climate statistics, WAsP calculates a generalized wind climate and, in turn, WAsP calculates a predicted wind climate statistics and AEP (annual energy production). It is our recommendation that your selection of wind data should cover a sufficient time period. At least one year, but preferably several (whole) years. Cheers,
  5. Hi vob, Can you please send this message to "waspsupport@dtu.dk" and include your WAsP workspace? Thanks, Brian
  6. Hi Gyeongil, Regarding your question 2, we decided to increase the generalized wind climate default height range because we had on more occasions been contacted by WAsP users who needed to make calculations beyond the old height range. So this does not mean that we have made changes or improvements targeted at "tall profiles" yet. Best regards, Brian
  7. WAsP 11.4 Release D WAsP version 11.4.0016 has been released. It restores display ability in Google Earth.
  8. Please update your WAsP Engineering and re-create recent projects There is a problem with the water roughness calculations in WAsP Engineering 3.1 which means that fetch calculations will not be properly invoked. We recommend that you install the latest release of WAsP Engineering (3.1 release ‘E’) and recreate any projects which have been created with WEng 3.1. What is the scope of the problem? This only applies to projects created with WEng 3.1 from vector maps (using the built-in gridding converter), or projects created from grid maps which were created using the updated GridMaker utility program which was released with WEng 3.1. If you have projects created from your own grid maps, or which were generated using WEng 3.0 or earlier, then these are not affected. What is the effect of the bug? The roughness grid map will not represent water correctly. This means that the fetch calculation and water roughness are not engaged. In offshore and coastal sites, this will affect the wind speed predictions. How can I see whether my project is affected? In your existing WEng (Version 3.1 release ‘A’, ‘B’, ‘C’ or ‘D’), you should open the fetch map and check that the distances to coasts are correctly displayed. If not, it’s a sign that the project should be recreated or fixed. What should I do? After installing the new WEng release (Version 3.1 release ‘E’), re-open the project. You should see a dialog alerting you to the problem, and offering to fix the maps. The roughness map is quickly corrected. Open the grid and check that water areas are correctly illustrated in blue. If this looks OK, then check the fetch map. I use WindPRO, am I affected? You may be, but there is no need to recreate any projects. Just repeating the calculations (after installing this update) will be enough to correct the results. Questions? If you have any questions about this bug and its resolution, please contact WAsP support for clarification or guidance.
  9. The Windfarm Assessment Tool (WAT) is a post-processor of results from WAsP and WAsP Engineering, supporting the site assessments of various IEC standards. The new release contains several new features. The Windfarm Assessment Tool (WAT) is for wind energy engineers: • Include effects of wind sector management, technical losses and uncertainty in windfarm production estimates • Check site suitability of a given wind turbine class • Make terrain assessments in preparations for power-performance measurements The main feature of WAT is still the IEC 61400-1 site assessment based on combined results of WAsP and WAsP Engineering. It is possible to model ambient turbulence predictions by combination of observations at reference masts and predictions of conditions at turbine sites by WAsP Engineering. Users reported problems importing turbulence statistics in the prescribed format, but it is now possible to calculate these statistics within WAT by analysis of observed time series. The WAT model for annual energy production (AEP) includes technical losses for sector management, turbine availability, losses in internal transmission lines and grid curtailment. AEP uncertainty is modelled by user-defined uncertainties on wind speeds, wind farm production or combinations of these. Technical losses and uncertainties are modelled in a non-linear way and the effects depend on each other. Power curves for individual turbines are optionally adapted to the local air density. Users who are interested in AEP estimates but not in site assessments, may import a WAsP workspace and avoid detailed calculations by WAsP Engineering. The terrain and obstacles assessments for power performance measurements are enhanced and now support the IEC 61400-12-2 standard for measurements by nacelle anemometers. WAT can now run in a simplified mode for assessments related to power performance measurements only, and for this you no longer have to generate input by WAsP Engineering. The only information needed is terrain elevation plus turbine and obstacle geometry, which you edit from within WAT. The user interface has been simplified and options are hidden when irrelevant. WAT is now distributed with sample data and has links to video tutorials on YouTube. Access to WAT 4 results is included with a WAsP 11 licence. You will be able to install and try WAT without a WAsP licence, but results will be hidden. New features in WAT version 4 are: • A simplified user interface • AEP uncertainty estimates • AEP corrections for turbine availability and transmission power loss • Import of WAsP projects for AEP calculations • Power curve correction for local air density • Turbulence statistics by observed time series • Improved export and import of turbulence statistics • Improved indication of neighbouring turbines in the sector management dialogue • Transparent display of IEC 61400-12-1 performance measurement zones • Improved accuracy when reading IEC 61400-12-1 measurement sectors from a WAT project file • Support for IEC 61400-12-2 terrain and obstacle assessments • IEC 61400-12-x assessment with no WAsP or WEng input • Editor for obstacle geometry • Corrected IEC 61400-1 terrain complexity plot • Corrected IEC 61400-12-1 terrain assessment • Corrected interpolation of WAsP/WEng site conditions You can download the new WAT 4 version at our website.
  10. Hi vman, In order to be able to calculate a wind farm power curve (power output of the wind farm as a function of wind speed and wind direction at a common reference position), it is necessary to refer the wind speed and wind direction to a common reference position; the reference site. Please refer to the WAsP help file for further information about reference sites. Cheers, Brian
  11. Hi Jan, Here's a WAsP turbulence intensity example - simulating the Bolund case: In the wake of Bolund: - The speed-up factor from the WAsP CFD result file, A = U/Uref = 0,3066 - The turbulence from the WAsP CFD result file is K = sqrt(TKE)/Uref = 0,1658. Uref is the wind speed at the inlet of the computational domain. WAsP will give the turbulence intensity as 0,1658/0,3066 = 0,54 = 54 % WAsP will truncate the turbulence intensity at 100 % The speed-up factor and the turbulence from the WAsP CFD result file are both wind speed independent (WAsP CFD calculations are Reynolds number independent). Therefore, the turbulence intensity given by WAsP is wind speed independent as well. Also, the turbulence intensity calculated by WAsP CFD represents neutral atmospheric conditions. The atmosphere generally approaches neutral conditions for high wind speeds, so the calculated turbulence intensity should represents these cases. Cheers, Brian
  12. WAsP 11.1 includes a couple of quite extraordinary new features for siting of wind turbines, wind farms and met stations. WAsP CFD result files now include turbulence data and with WAsP 11.1 it is now possible to show WAsP CFD turbulence intensity and flow inclination in WAsP resource grids. In WAsP 11.1 these same properties are now also included in the ”Site effects” tab for turbine sites, reference sites and met stations. New features: •Integration of turbulence and flow inclination from WAsP CFD results files •Site effects tab now separates IBZ and CFD information (relevant reports too) •During a calculation, loading CFD layers from the results is significantly faster •Added a dialog when sending a WAsP CFD job to the computer cluster using the WAsP CFD calculation manager, informing that you are about to spend WAsP CFD calculation credits •Site effects results once copied to clipboard have three decimal format •Recalculated WAsP CFD result files for Parco Ficticio so that includes the turbulence and flow inclination results •Removed script "cross prediction excel (save ws)" and updated "cross prediction– Excel" •When CFD filenames are auto generated, concatenating in part of the job GUID, the first character is dropped off Fixes the following problems: •OWC-Window failure fixed •Prompted switch from LIB to GWC export extension is now working properly Cheers, Brian
  13. A new version of the WAsP Map Editor version 11.3 is available from http://www.wasp.dk/ It has the following new features: - SRTM Map importer implemented - Projection database reading (Asian Windows versions) error fixed - Shape file reading errors fixed - Shape-file elevation from associated dBase file now supported - DXF-map reading bug re. files with unspecified DXF-format version now fixed
  14. The WAsP Team is happy to announce that WAsP 11 is released on 29 April 2013. WAsP 11* is the latest version of the Wind Atlas Analysis and Application Program, which now includes a fundamentally new approach to Computational Fluid Dynamics (CFD) for wind resource assessment in complex terrain**. We call this new feature WAsP CFD and it combines WAsP with the CFD solver EllipSys in the elegant WAsP graphical user interface that you already know. The design philosophy of WAsP CFD has been a joint model approach; you set up the WAsP project and can subsequently opt for a CFD solution if the site complexity justifies the added computational effort. WAsP CFD will add value to wind energy projects by helping you maximize production and minimize uncertainty. WAsP CFD offers the possibility to make wind resource assessments in complex terrain which are: • Accurate: EllipSys adapted specifically for flow over terrain and WAsP CFD developed specifically for wind resource assessment • Reliable: Reproducible, high quality calculations, applying the Wind Atlas Method • Fast: Only a few hours per WAsP CFD calculation • Easy: No knowledge about CFD needed • Cheap: Low price per WAsP CFD calculation, no hardware investment necessary and no CFD training needed Other major new features in WAsP 11 are: • New Terrain Analysis hierarchy member • New Generalized Wind Climate file format replaces the Wind Atlas file format • Profile model and parameter settings are now part of the Generalized Wind Climate file • Unlimited number of points in WAsP terrain map files • Dongle-free license system What does it cost and how do I order it? WAsP 11 license • EUR 3500 for one WAsP 11 license • EUR 1750 per additional WAsP 11 license • EUR 525 per upgrade from WAsP 10 license • EUR 1000 per upgrade from earlier WAsP versions WAsP CFD Calculation Credits • EUR 200 per WAsP CFD Calculation Credit (1 area/tile of 2 km by 2 km) During the first month after release, the first 75 organizations/companies to buy WAsP 11 licenses will get 10 free WAsP CFD Calculation Credits intended for WAsP CFD calculations of a couple of complex terrain sites. As WAsP 11 is a dongle-free version, we will be able to send you the licence file by email, as soon as we have registered your payment. We hope that you will be as excited about WAsP 11 as we are! Best regards, The WAsP Team __________________ * Please note that WAsP 11 no longer refers to Tall Profiles. WAsP 11 now refers to WAsP CFD (and dongle-free licensing, etc.). Tall Profiles will hopefully be released in a later WAsP version, when we are able to conclude that it's providing a significant and consistent improvement over the standard WAsP profile model. ** Please also note that WAsP CFD is not yet for assessment of wind load parameters, e.g. turbulence and flow inclination angles. We have started the work on WAsP Engineering, which will allow you to use WAsP CFD for this purpose. In the meantime, you can continue calculating wind load parameters using WAsP Engineering in the present version.
  15. With the release of WEng 3 last December, we will no longer be supporting WAsP Engineering 2 and we therefore recommend all WEng 2 users to upgrade their licences. If we receive the upgrade order in 2012, we will offer a 10% discount.
×
×
  • Create New...