NREL: System Advisor Model (SAM)

The System Advisor Model (SAM) is a performance and economic model designed to facilitate decision making for people involved in the renewable energy industry, ranging from project managers and engineers to incentive program designers, technology developers, and researchers.

SAM is developed by the National Renewable Energy Laboratory (NREL) in collaboration with Sandia National Laboratories and in partnership with the U.S. Department of Energy (DOE) Solar Energy Technologies Program (SETP). The SETP began developing SAM in 2004 for analysis to support the implementation of the SETP Systems Driven Approach. Since then, SAM has evolved to model a range of renewable energy technologies and is used worldwide for planning and evaluating research and development programs, developing project cost and performance estimates, and for academic research.

SAM makes performance predictions for grid-connected solar, small wind, and geothermal power systems and economic estimates for distributed energy and central generation projects. The model calculates the cost of generating electricity based on information you provide about a project's location, installation and operating costs, type of financing, applicable tax credits and incentives, and system specifications. SAM also calculates the value of saved energy from a domestic solar water heating system.

SAM is based on an hourly simulation engine that interacts with performance, cost, and finance models to calculate energy output, energy costs, and cash flows. The software can also account for the effect of incentives on project cash flows. SAM's spreadsheet interface allows for exchanging data with external models developed in Microsoft Excel. The model provides options for parametric studies, sensitivity analysis, optimization, and statistical analyses to investigate impacts of variations and uncertainty in performance, cost, and financial parameters on model results.

SAM models system performance using the TRNSYS software developed at the University of Wisconsin combined with customized components. TRNSYS is a validated, time-series simulation program that can simulate the performance of photovoltaic, concentrating solar power, water heating systems, and other renewable energy systems using hourly resource data. TRNSYS is integrated into SAM so there is no need to install TRNSYS software or be familiar with its use to run SAM.