Parametric and Statistical Analysis in SAM

This webinar was presented by Paul Gilman on January 22, 2015, and includes a description and demonstrations of SAM's parametric, stochastic, and P50/P90 simulation options. It also explains how to use cases in a SAM project file to compare different analysis scenarios, and demonstrates how to use SAM's built-in Create Tornado Chart macro.

Overview (8:16 minutes)

This video briefly describes each of the options for using SAM for analysis scenarios that involved multiple simulations, and defines the terms "parametric," "p50/p90," "stochastic," "project file," and "case."

Use Inputs Browser to compare values of input variables in different cases (2:13)

Use SAM's inputs browser to list values of all input variables in a case, and to compare values of input variables in different cases. It also explains SAM's start menu, where you can find commands for opening, saving, and closing project files and LK scripts.

Parametric simulations (7:25)

Use SAM's parametric simulation option to assign more than one value to input variables. It uses a PVWatts example with a parametric study on DC-to-AC ratio, and also shows how to set up an optimization for the parabolic trough model to determine the combination of solar multiple and thermal energy storage capacity that minimizes the PPA price.

P50/P90 simulations (5:54)

Run a P50/P90 analysis when you have a collection of ten or more weather files. It also shows where to find files suitable for P50/P90 analysis (for some U.S. locations), and how to troubleshoot and fix some kinds of weather file problems.

UPDATE 10/16/2017: For a video demonstrating how to download weather files for P50/P90 from the NREL NSRDB, see

Stochastic simulations (3:48)

Use the stochastic simulation option to define a range of values for input variables using parameters for a statistical distribution.

Create Tornado Graph macro (LK Script)

Use the built-in Create Tornado Chart macro to create a tornado plot.

Q&A session (32:00)

The question and answer session that followed the webinar. Questions were wide-ranging, and only one or two were about the webinar topic, so we've posted them here separately from the other recordings

Supporting materials

Presentation slides (PDF 2.4 MB)

Link to Solar Resource 101 webinar (February 2014) with more details about P50/P90 analysis

Link to single year data files suitable for P50/P90 simulations from the National Solar Radiation Database (U.S. locations only)

SAM files used for the webinar demonstrations:

Using cases to compare analysis scenarios (SAM 87 KB)

Simulation option examples: Parametrics, Stochastic, P50/P90 (SAM 956 KB)

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