Also from NREL, SAM is a sophisticated, free software for project programmers. Best for: Detailed financial and performance modeling. Pros: Highly granular data, completely open-source.

Helioscope software is a type of computer program designed to analyze and visualize solar data, particularly for helioseismology and solar physics research. These tools help scientists study the Sun's internal structure, oscillations, and activity. While many commercial and proprietary helioscope software options exist, several free and open-source alternatives are available for researchers and enthusiasts.

HelioScope is widely considered the "sweet spot" between easy-to-use residential tools and overly complex engineering software like PVsyst.