ASTM G173-03(2020)
Standard Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37° Tilted Surface

Standard No.

ASTM G173-03(2020)

Release Date

2020

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM G173-23

Latest

ASTM G173-23

Scope

1.1 These tables contain terrestrial solar spectral irradiance distributions for use in terrestrial applications that require a standard reference spectral irradiance for hemispherical solar irradiance (consisting of both direct and diffuse components) incident on a sun-facing, 37° tilted surface or the direct normal spectral irradiance. The data contained in these tables reflect reference spectra with uniform wavelength interval (0.5 nanometer (nm) below 400 nm, 1 nm between 400 and 1700 nm, an intermediate wavelength at 1702 nm, and 5 nm intervals from 1705 to 4000 nm). The data tables represent reasonable cloudless atmospheric conditions favorable for photovoltaic (PV) energy production, as well as weathering and durability exposure applications. 1.2 The 37° slope of the sun-facing tilted surface was chosen to represent the average latitude of the 48 contiguous United States. A wide variety of orientations is possible for exposed surfaces. The availability of the SMARTS model (as an adjunct, ADJG173CD3 ) to this standard) used to generate the standard spectra allows users to evaluate differences relative to the surface specified here. 1.3 The air mass and atmospheric extinction parameters are chosen to provide (1) historical continuity with respect to previous standard spectra, (2) reasonable cloudless atmospheric conditions favorable for photovoltaic (PV) energy production or weathering and durability exposure, based upon modern broadband solar radiation data, atmospheric profiles, and improved knowledge of aerosol optical depth profiles. In nature, an extremely large range of atmospheric conditions can 1 These tables are under the jurisdiction of ASTM Committee G03 on Weathering and Durability and are the direct responsibility of Subcommittee G03.09 on Radiometry. Current edition approved June 1, 2020. Published July 2020. Originally approved in 2003. Last previous edition approved in 2012 as G173 – 03(2012). DOI: 10.1520/G0173-03R20. 2 The boldface numbers in parentheses refer to the list of references at the end of this standard. 3 Available from ASTM International Headquarters. Order Adjunct No. ADJG173CD. Original adjunct produced in 2005. Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. 1 be encountered even under cloudless skies. Considerable departure from the reference spectra may be observed depending on time of day, geographical location, and changing atmospheric conditions. The availability of the SMARTS model (as an adjunct (ADJG173CD3 )to this standard) used to generate the standard spectra allows users to evaluate spectral differences relative to the spectra specified here. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ASTM G173-03(2020) Referenced Document

• ASTM E490 Standard Solar Constant and Zero Air Mass Solar Spectral Irradiance Tables
• ASTM E772 Standard Terminology Relating to Solar Energy Conversion

ASTM G173-03(2020) history

• 2023 ASTM G173-23 Standard Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37° Tilted Surface
• 2020 ASTM G173-03(2020) Standard Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37° Tilted Surface
• 2003 ASTM G173-03(2012) Standard Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37deg; Tilted Surface
• 2003 ASTM G173-03(2008) Standard Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37176; Tilted Surface
• 2003 ASTM G173-03e1 Standard Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37176; Tilted Surface
• 2003 ASTM G173-03 Standard Tables for Reference Solar Spectral Irradiances: Direct Normal and Hemispherical on 37176; Tilted Surface