Solcast TMY data and NREL SAM (System Advisor Model)

The US National Renewable Energy Laboratory maintains one of the most widely used PV modelling and planning software options - SAM, the System Advisor Model.

SAM is a free piece of software model, focused on enabling financial decision making for several renewable energy applications, including PV power modelling.

It is suitable for all scales of PV systems, from small residential rooftop to large utility-scale sites.

Solcast TMY data

Solcast is a leading provider of Typical Meteorological Year (TMY) data, which is a standard file type for PV modelling.

TMY files represent the climatological averages of solar irradiance and related weather data, which are built using historical satellite and re-analysis data.

Solcast TMY files have industry-leading uncertainty levels, and are used by solar developers around the world for the purposes of PV system planning and financing.

Accessing Solcast TMY data

Solcast offers TMY data via monthly subscriptions, with no lock-in contracts, including a 'Free' tier where new users can test the TMY files for free.

An increasing number of PV software options now offer direct integration with Solcast's TMY API, which delivers P50 scenarios directly into PV simulations.

In addition to PVSyst, you can now access Solcast TMY data directly into SAM through the use of a new software script published to GitHub.

Pulling Solcast TMY data into NREL SAM

Your first step for accessing Solcast TMY data into NREL SAM, is of course to register for your free Solcast API Toolkit account!

Next, you'll need to download the LK sample script from GitHub located here.

Using the NREL SAM script to pull in Solcast TMY data

Step 1

After you have made a local copy of the LK script from GitHub, you'll want to open the script from within SAM:

Step 2: Locate your API key

Next, carefully read the instructions provide from within the LK script.

You'll need to locate your unique Solcast API key, which can be located within the API Toolkit at this link.

Step 3: Add the API key

Add this API key into the script at:

key=''

You should then prepare a list of a latitude and longitude locations, decimal degree format, for the sites of interest that you want to retrieve data from.

For testing, choose one of these locations and add it to the script

Step 4: Run the LK script from within SAM

The script will make a request to the Solcast API and download the CSV to your SAM "Downloaded Weather Files" folder.

Note: this will consume a 'request' from your chosen TMY P50 subscription. For more information about how many requests / month you will have, review our pricing page here.

The TMY file should then be visible in the SAM's Solar Resource Library.

Step 5: Find, Inspect and Use your TMY data

Once you've successfully added the Solcast TMY file to your Solar Resource Library, you can locate and inspect the data.

First, open your SAM project and select the Solcast data file from your resource library.

Next, you can preview the TMY file weather data information using the "View Data" option to inspect the data in the file.

This will allow you to check out the various weather parameters with the file, including the solar radiation parameters. Our example below is for GHI data.

Time to start planning your next solar project!

If you've not yet created a Solcast API Toolkit account, getting started is completely free.

As a new user, you can access our 'Free Tier' subscription, and get 2x free TMY P50 files.

There are also some other great free tools there as well, including Monthly Averages and Time-Series data, although these do not currently integrate with SAM, you may find them useful.

Create your API Toolkit account here!