Merra-2 access and data compilation

[JOSE MARIA PEREZ ARCOS]

Hello, 

We are interested in WAsP, but we are not sure about some issues. As an Asset Management Advisor Company, we are having lots of commercial opportunities in Wind assessments (our core business is PV though), and we would like to be informed before purchase about several requirements. One of them is the resource wind data to validate Meteo tower on site real wind data mesurements, like MERRA-2. Is it possible to access this data (eg 20 years) and extract averages or export data and graphics? If so, what other satellite or ground date bases are available?

Thanks in advance

Best. Jose Maria

[Morten]

WAsP applies the wind atlas method. The traditional input is 10-min time series of wind speed and direction measured by a Lidar or anemometer on a mast near the site of application. First step in the  analysis is to remove effects of local terrain around the reference meteorological station and produce mean wind climate statistics for the resulting generalized winds, i.e. winds over flat uniform terrain. At the site of application, WAsP will model terrain effects near every wind turbine site and predict local mean wind climates based on speed-up factors and the generalized mean wind climate. 

Now, reanalysis data are predicted by global circulation models with simplified terrain models capturing only large-scale flow effects. To use them in a WAsP context we need to calculate the generalized wind climate by a method we call downscaling, see https://orbit.dtu.dk/en/publications/mesoscale-and-microscale-downscaling-for-the-wind-atlas-of-south-. We have not done so with the  MERRA2 data as input, but the Global Wind Atlas made a downscaling with the WRF (mesoscale) and WAsP (microscale) flow models based on the ECWMF ERA5 2008-2017 reanalysis dataset, see https://globalwindatlas.info/about/method for a quick read. It is possible to download the GWA generalized wind climates from https://globalwindatlas.info/ and use them in WAsP for preliminary wind resource estimates when local data are unavailable. We still recommend local measurements for bankable results.