IEC 60904-3:2019

Overview

IEC 60904-3:2019 - "Photovoltaic devices - Part 3: Measurement principles for terrestrial photovoltaic (PV) solar devices with reference spectral irradiance data" - defines the fundamental measurement principles used to determine the electrical output of PV cells, modules, sub‑assemblies and systems. The standard provides a common reference terrestrial solar spectral irradiance distribution (AM1.5 global and AM1.5 direct) and a clarified angular irradiance definition to ensure repeatable, comparable performance ratings for PV devices measured under natural or simulated sunlight.

Key topics and technical requirements

• Reference spectral data (AM1.5): The document supplies global and direct reference solar spectral irradiance distributions used to characterize PV performance and to classify solar simulators. These datasets were generated using the SMARTS spectral model (version 2.9.2) and are supplied as tabulated data (Excel file attached to the publication).
• Measurement principles: Procedures for measuring PV current‑voltage (I‑V) characteristics under known temperature and irradiance conditions, with correction to Standard Test Conditions (STC) as per IEC 60891.
• Irradiance measurement methods: Use of PV reference devices (with known spectral responsivity) or thermopile-type detectors (pyranometers) to measure incident irradiance; temperature measurement methods are referenced to IEC 60904‑1 and IEC 60904‑5.
• Spectral mismatch and responsivity: Requirement to know the spectral distribution of incident light and the device spectral responsivity (IEC 60904‑8) to compute spectral mismatch corrections (IEC 60904‑7).
• Angular distribution: Clarified angular irradiance specification so the reference radiation is defined for normal incidence; more realistic climate/geometry cases are referenced to IEC 61853‑4.
• Edition changes (2019): Spectral data were recalculated to correct rounding errors from the previous edition and the angular distribution was clarified.

Practical applications and who uses this standard

IEC 60904-3 is essential for:

• PV module and cell manufacturers establishing rated power (W) under STC.
• Test laboratories and certification bodies performing accredited power and performance tests.
• Solar simulator manufacturers and test facilities seeking to meet spectral classification requirements (linked to IEC 60904‑9).
• Researchers and system designers performing spectral mismatch corrections or modeling real-world energy yield.
• Quality assurance and R&D teams comparing different PV technologies or materials under a common reference spectrum.

Keywords: IEC 60904-3, photovoltaic, PV measurement, solar spectral irradiance, AM1.5, solar simulator, spectral mismatch, I‑V measurement, STC.

Related standards (selected)

• IEC 60904‑1 - I‑V measurement procedures
• IEC 60904‑2 - PV reference device requirements
• IEC 60904‑7 - Spectral mismatch correction computation
• IEC 60904‑8 - Measurement of spectral responsivity
• IEC 60904‑9 - Solar simulator performance requirements
• IEC 61853‑4 - Reference climatic profiles for PV module testing