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NSRDB by NLR

The National Solar Radiation Database, NSRDB , is provided by the National Laboratory of the Rockies, NLR. It contains solar radiation and meteorological data for solar energy applications.

The database was originally focused on the United States, but now includes several regional and global datasets. In PVsyst, NSRDB data can be accessed for most locations worldwide, depending on the selected dataset and period.

Access and available data

TMY data from available NSRDB models can be accessed directly through an API when defining a site and metrological data in PVsyst. NSRDB data can also be imported as a known format.

Datasets are available in the NSRDB Viewer for free. Both historical time series and TMY are available. Historical time series are provided for specific years, with time resolutions depending on the selected dataset, typically 15, 30 or 60 minutes. TMY datasets are generally provided as hourly data. For PVsyst simulations, the most relevant variables are:

  • GHI, global horizontal irradiance
  • DNI, direct normal irradiance
  • DHI, diffuse horizontal irradiance
  • ambient temperature
  • wind speed

Some NSRDB files may also contain additional variables that can be useful for data checking or for specific uses, such as:

  • clear-sky GHI
  • relative humidity
  • albedo
  • precipitable water

NSRDB files downloaded from the Viewer are generally provided in the SAM CSV format. Older NSRDB products may exist as TMY2 or TMY3 files. These are legacy formats and should normally be used only for compatibility with older projects. For new projects, the recommended workflow is to use the current NSRDB Viewer / SAM CSV format.

Data sources

NSRDB data are derived from satellite and atmospheric data, using both physics-based and empirical modelling approaches. The current NSRDB is modelled using NLR’s Physical Solar Model, PSM . Some NSRDB datasets are based on the SUNY semi-empirical satellite model, which derives irradiance from satellite cloud information.