Weather Data Online

SAM allows you to use correctly formatted weather files that you download from the web. Weather files must meet the following requirements:

Be stored in a folder on your computer that you have specified in SAM as containing weather files. See Weather File Folders for details.

Be in TMY2, TMY3, EPW, SMW, or SRW file format. See Weather File Formats for details.

This section describes how to download and use weather files from the NREL National Solar Radiation Database, EnergyPlus website, and from SAM weather file collections for India prepared by NREL, and for Australia prepared for the Australian Solar Thermal Energy Association (AUSTELA).

Note. If you cannot find weather data for your location on one of those websites, you may want to purchase data from one of the following companies (all links last accessed July 2013):
 
 • Meteonorm
 • SolarAnywhere
 • SolarGIS
 • Weather Analytics
 
NREL cannot guarantee that files from sources outside of NREL will work correctly in SAM.

NSRDB Typical Meteorological Year (TMY) data

NREL's National Solar Radiation Database (NSRDB) typical meteorological year (TMY) data represents average weather data over a range of years for locations in the United States. Each TMY file contains data from different years within the range. For example, a TMY file for a given location might contain 1995 data for the month of February, 2001 data for March, 1998 data for April, etc. The NREL typical year data is based on and analysis of solar radiation and meteorological data measured or modeled at each location.  The NSRDB TMY files are appropriate for economic and performance predictions of a project over a long analysis period. For details about the methodology for developing the TMY data, see the user manuals on the NSRDB website.

There are two versions of the NSRDB TMY database, TMY2 and TMY3. The TMY2 files are available for 239 locations and represent the years 1961-1990. The TMY3 files are available for 1,020 locations and represent the years 1991-2005. The TMY3 database is an update of the TMY2 database and includes the 239 TMY2 locations. For those 239 locations, the time span in the TMY3 database is 1976-2005. The TMY3 data were developed from more recent data and better modeling techniques than the TMY2 data. However, the TMY3 data was developed using data from a shorter time period than the TMY2 data, so may be less representative of the resource over the long term. On the other hand, the TMY2 data includes effects from two major volcanic eruptions in 1981 and 1991 that reduced the solar resource during the TMY2 time period. If both TMY2 and TMY3 files are available for your project site, you may want to run SAM with both sets of data to compare results.

When you install SAM, it copies a the complete NSRDB TMY2 data set to the SAM installation folder on your computer. To use TMY2 data, you choose a location from the list on the Location and Resource page. To use an NSRDB TMY3 file, you must first download it from the web.

To download a TMY3 file from the web:

1.On the Location and Resource page, click the Best weather data for the U.S. (1200 + locations in TMY3 format) link to open the NSRDB TMY3 database page in your web browser.

2.On the NSRDB website, click the In alphabetical order by state and city link.

3.Scroll to the state and city at or nearest your location.

4.Click the identification code link for the location to download the TMY3 file.

5.Save the file in your SAM weather file folder. If you do not have a SAM weather file folder, see Manage Weather File Folders for instructions.

6.In SAM, on the weather file input page, click Refresh.

The weather file should appear in the Location list, toward the bottom of the list.

EnergyPlus Weather (EPW) files: Data for locations outside the United States

You can download weather data in EPW format for locations around the world at no cost from the EnergyPlus weather data website at the following website:

http://www.eere.energy.gov/buildings/energyplus/cfm/weather_data.cfm.

For information about the EPW weather files, see the following websites:

For a description of the file format: http://apps1.eere.energy.gov/buildings/energyplus/weatherdata_format.cfm

For a description of data sources: http://apps1.eere.energy.gov/buildings/energyplus/weatherdata_sources.cfm

To download an EPW file:

1.On the Location and Resource page, click Best weather for international locations (in EPW format) to open the EnergyPlus Weather Files website in your web browser.

2.On the EPW website, navigate to the region, country, and location you want to model.

3.Download the EPW file for the location you are modeling.

If there is not an EPW file for the location, download the ZIP file and extract the EPW file.

4.Save the file in your SAM weather file folder. If you do not have a SAM weather file folder, see Manage Weather File Folders for instructions.

5.In SAM, on the Location and Resource page, click Refresh.

The weather file should appear in the Location list, toward the bottom of the list.

For some regions, you can download an EPW file directly for a location. For example, for Bangladesh, you can download the data for Dhaka by right-clicking the blue square next to the word EPW for Dhaka. Be sure to save the file with the .epw extension.

SS_Climate-EPW-Blue-Square

For other regions, you must first download a zip file containing the EPW file and then extract the EPW file. For example, for Malaysia, you can download the data for Kuala Lumpur by right-clicking the red square next to the word ZIP for Kuala Lumpur. After downloading the zip file, you can extract the EPW file.

SS_Climate-EPW-Red-Square

NREL India Weather Files for SAM

NREL has prepared a set of files in the TMY3 format (.csv) with single-year data between 2002 and 2008 for nine locations in India. This data is not typical-year data because there are not enough years for a typical-year analysis. You should run simulations using each of the seven years for a given location to get a sense of the range of values of your performance and financial metrics of interest. See the India SAM file documentation available from the website for a description of the data.

To download the NREL India Weather Files for SAM:

1.In your web browser, go to http://www.nrel.gov/international/ra_india.html.

2.On the website, under India Weather Files Designed to be Used in System Advisor Model (SAM), download the .zip file for the location you want to model.

Each ZIP file contains a set of weather files for a location in the TMY3 format (.csv) for a range of years.

3.Extract the CSV files and save them in your SAM weather file folder. If you do not have a SAM weather file folder, see Manage Weather File Folders for instructions to create one.

4.The weather files should appear in SAM on the Location and Resource page in the Location list, toward the bottom of the list. If you do not see the files, try clicking Refresh.

 

AUSTELA Australia Solar Data Files for SAM

IT Power Australia and NREL collaborated on a project supported by the Australian Renewable Energy Agency for the Australian Solar Thermal Energy Association to develop a set of SAM sample files and weather files. See the Australian Companion Guide to SAM for Concentrating Solar Power from the website for a description of the weather files.

To download the AUSTELA Australia Solar Data Files for SAM:

1.In your web browser, go to http://www.austela.org.au/projects.

2.On the website, click the A selection of solar data files for input to SAM for selected representative Australian sites and years link to download the .zip file.

The ZIP file contains a set of weather files several locations in the TMY3 format (.csv) for a range of years, and the set of Australia weather files available on the EnergyPlus website in EPW format (.epw).

3.Extract the CSV and EPW files that you want to use and save them in your SAM weather file folder. If you do not have a SAM weather file folder, see Manage Weather File Folders for instructions to create one.

4.The weather files should appear in SAM on the Location and Resource page in the Location list, toward the bottom of the list. If you do not see the files, try clicking Refresh.