System Advisor Model (SAM)

The SAM Open Source Project repository contains the source code, tools, and instructions to build a desktop version of the National Renewable Energy Laboratory's System Advisor Model (SAM). SAM is a simulation program for electricity generation projects. It has models for different kinds of renewable energy systems and financial models for residential, commercial, and utility-scale projects. For more details about SAM's capabilities, see the SAM website at https://sam.nrel.gov/.

For a short video describing the SAM repositories, see https://youtu.be/E5z1iiZfZ3M.

The SAM release notes are in https://github.com/NREL/SAM/blob/gh-pages/doc/releasenotes.html.

The desktop version of SAM for Windows, Mac, or Linux builds from the following open source projects:

• SSC is a set of "compute modules" that simulate different kinds of power systems and financial structures. It can be run directly using the SAM Software Development Kit. This is the source code for SAM's models, and is the repository to use for researching the algorithms underlying the models.

• LK is a scripting language that is integrated into SAM. SAM's user interface uses LK to calculate values to display on input pages. The user interface includes a script editor that allows users to write their own scripts from the user interface.

• wxWidgets is a cross-platform graphical user interface platform used for SAM's user interface, and for the development tools included with SSC (SDKtool) and LK (LKscript).

• WEX is a set of extensions to wxWidgets for custom user-interface elements developed specifically for SAM, LK script, and DView.

• Google Test is a C++ test framework that enables comprehensive unit-testing of software. Contributions to the project will eventually be required to have associated unit tests written in this framework.

• jsoncpp is a C++ library that allows manipulating JSON values, including serialization and deserialization to and from strings.

• Python/Miniconda is for integration of Python scripts with the SAM user interface.

This repository, SAM, contains the code for SAM's user interface that assigns values to inputs of the SSC compute modules, runs the modules in the correct order, and displays simulation results. It also includes tools for editing LK scripts, viewing time series results, and generating shade data from a 3-dimensional representation of a photovoltaic array or solar hot water collector and nearby shading objects.

The SAM repository also includes two libraries from Sandia National Laboratories, stepwise, and LHS, which are distributed as part of the Dakota platform, licensed under LGPL.

Building SAM

For build instructions see the wiki with specific instructions for:

• Windows
• Mac
• Linux

Contributing

If you would like to report an issue with SAM or make a feature request, please let us know by adding a new issue on the issues page.

If you would like to submit code to fix an issue or add a feature, you can use GitHub to do so. Please see Contributing for instructions.

License

SAM's open source code is copyrighted by the Alliance for Sustainable Energy and licensed with BSD-3-Clause terms, found here.

The stepwise and LHS LGPL licensed libraries from Sandia National Laboratories are pre-compiled Fortran libraries that are included in the SAM repository as binaries in the Sandia folder. You can replace the binaries with different versions by compiling your own version and replacing the binary/executable viles in the Sandia folder.

Citing this package

System Advisor Model Version 2025.4.16 (2025). SAM source code. National Renewable Energy Laboratory. Golden, CO. Accessed April 18, 2025. https://github.com/NREL/SAM