Dear Stephen,
For documentation of both SAM's detailed photovoltaic model and PVWatts, please see the Performance Model documentation page:
sam.nrel.gov/performance
The latest version of SAM (2016.3.14 r4) has a code generator that generates code in each of the languages supported by the SAM SDK, including Python. That might be a useful way for you to avoid errors caused by incorrectly assigning values to inputs. To use the code generator, start SAM and create a case for a system like the one you would like to model in the SDK. Then, on the Case menu (click the carrot symbol next to the case's name on the Case tab at the top of the SAM window), click
Generate code, and choose a language.
In
pvsamv1, you can use
instead of
to use an array of weather data in place of a weather file. However, it is not possible to run
pvsamv1 for a single time step as it is with
pvwattsv5_1ts, so you have to provide
pvsamv1 with a full year's worth of weather data.
In PVWatts V5, when you choose
1 Axis Tracking (
= 2) or
1 Axis Backtracking (
= 3) for the Array type, the model automatically calculates self-shading losses. In
pvsamv1, it is possible to use one-axis tracking with no self shading, but not in PVWatts.
Best regards,
Paul.