SAM's solar water heating (SWH) model represents a one-tank water or glycol system with an auxiliary electric heater. The solar water heating performance model works with either the residential or commercial financial model, and assumes that the solar water heating system displaces purchases of electricity for an electric water heater. Installation and operating costs, financial assumptions, and retail electricity prices determine the value of the energy delivered by the solar water heating system.

The SWH model allows you to vary the location, hot water load profiles, mains and set temperature profiles, and characteristics of the collector, heat exchanger, and solar tanks. The model was developed at the National Renewable Energy Laboratory for SAM.

Christensen, C.; Maguire, J.; Burch, J.; DiOrio, N. (2014). Simplified Solar Water Heater Simulation Using a Multi-mode Tank Model. Solar 2014 Conference Presentation. (PDF 1.8 MB)

DiOrio, N.; Christensen, C.; Burch, J.; Dobos, A. (DRAFT 2014). Technical Manual for the SAM Solar Water Heating Model. (PDF 150 KB) NOTE: THIS DRAFT IS OUT OF DATE BUT PROVIDES USEFUL INFORMATION ABOUT THE MODEL.

When you create a new case or file, SAM populates inputs with default values to help you get started with your analysis. So, if you create a case for a residential solar water heating project, SAM populates the inputs on the Financing and System Costs pages with values that are reasonable for a typical residential solar water heating system in the United States. The default values are just a starting point: As you develop and refine your analysis, you should change the inputs to values that are appropriate for your analysis scenario.

Cassard, H.; Denholm, P.; Ong, S. (2011). Break-Even Cost for Residential Solar Water Heating in the United States: Key Drivers and Sensitivities. 54 pp.; NREL Report No. TP-6A20-48986. (PDF 3.5 MB)