Helioscope Software Free !!top!!

The is the most powerful free solar design tool on earth. Developed by the National Renewable Energy Laboratory (NREL), SAM allows you to model everything from a single residential rooftop to a 100MW utility-scale plant. It includes shading, financial models (tax credits, depreciation), and battery storage. The learning curve is steep, but if you master SAM, you don't need Helioscope.

If you need a tool that is permanently free rather than a trial, consider these options: PVWatts Calculator helioscope software free