ASTM G-173-03 Reference Spectra - This website provides tabular spectra for the AM0, AM1.5 global, and AM1.5 direct standards.
NREL Redbook – This website has a wealth of real solar resource data collected at hundreds of U.S. sites
US Department of Energy Photovoltaics Program – This is the top-level page for the US Department of Energy’s solar program, with links to summary descriptions of all of their funded programs, upcoming program opportunities, and other resources.
NOAA Solar Position Calculator – This is a handy on-line calculator to calculate the sun’s position at any time, anywhere on earth, with links to other solar position calculation resources.
US Solar Radiation Maps – This site has a variety of maps showing the available solar resource in graphical format.
SMARTS model – The “Simple Model of the Atmospheric Radiative Transfer of Sunshine” is is a comprehensive atmospheric spectral
PVWATTS version 2 - Researchers at the National Renewable Energy Laboratory developed PVWatts to permit non-experts to quickly obtain performance estimates for grid-connected PV systems. Version 2 can be run for locations within the 48 Contiguous States, Alaska and Hawaii.
PVWATTS version 1 - Version 1 can be used for locations accessible through links on a US map, or through a text list for U.S. sites; or for sites outside the US, through text lists by region.
Solar Advisor Model (SAM) - The Solar Advisor Model evaluates several types of financing (from residential to utility-scale) and a variety of technology-specific cost models. The technologies currently represented in SAM include concentrating solar power (CSP) parabolic trough and dish-Stirling systems and photovoltaic (PV) flat plate and concentrating technologies.
PVUSA System Rating Method – This paper describes a methodology developed by Sandia and widely accepted for performance rating of PV systems.
Typical Meteorological Year (TMY) Data – This site defines a standard data sat that can be used in system models to simulate hour-by-hour performance of PV systems.
Disclaimer: These links are provided for easy reference to useful information. Spectrolab takes no responsibility for the accuracy of the information on the referenced pages.