IEC 60904-9:2007

Overview

IEC 60904-9:2007 is an international standard published by the International Electrotechnical Commission (IEC) as part of the IEC 60904 series on photovoltaic devices. This part focuses specifically on the performance requirements for solar simulators used in the indoor measurement and testing of terrestrial photovoltaic (PV) devices. The standard defines classification criteria-namely, spectral distribution match, irradiance non-uniformity, and temporal instability-that are used to evaluate and rate solar simulators as Class A, B, or C for each parameter. The document also outlines detailed methodologies for performing these assessments, ensuring consistency and reliability when measuring the performance of PV devices in controlled environments.

Key Topics

1. Solar Simulator Classification

• Three Performance Categories: Simulators are rated separately for spectral match, irradiance uniformity, and temporal stability.
  • Spectral distribution match: Compares the simulator's spectrum to the reference solar spectrum (AM 1.5 Global, per IEC 60904-3) over specified wavelength ranges (400 nm to 1100 nm).
  • Irradiance non-uniformity: Measures how evenly light is distributed over the test area, determining the degree of variation in irradiance.
  • Temporal instability: Evaluates how consistently the irradiance is maintained during measurement, considering both short-term and long-term fluctuations.

2. Classification Ratings

• Class A: Highest accuracy and most stringent requirements for each category (e.g., spectral match ratio within 0.75–1.25, non-uniformity ≤2%, temporal instability ≤0.5% short term).
• Class B and C: Gradually looser tolerances allowing for less critical applications but still ensuring defined performance standards.

3. Measurement Procedures

• Provides guidance and methodologies for assessing:
  • Spectral match (using spectroradiometers and specific wavelength intervals)
  • Non-uniformity (using detectors across designated test areas)
  • Temporal stability (monitoring irradiance variation across relevant timeframes)
• Requires periodic verification to ensure continued compliance with the class rating.

4. Simulator Documentation

• Manufacturers must provide detailed nameplate and data sheet information, including intended use, class rating, measurement methods, irradiance range, and operating environment.

Applications

• Laboratory Testing of Photovoltaic Devices: Ensures accurate and repeatable PV module or cell performance measurements under simulated solar conditions.
• Product Quality Assurance: Used by manufacturers and testing labs to qualify or certify PV products against international standards.
• Research and Development: Enables consistent benchmarking and comparison of new photovoltaic technologies.
• Endurance and Exposure Testing: Supports long-term reliability assessments of PV modules under controlled simulated sunlight.

By setting global benchmarks, IEC 60904-9:2007 helps maintain uniformity, reliability, and comparability across performance measurement of PV devices, which is essential for manufacturers, quality assurance laboratories, and regulatory bodies.

Related Standards

• IEC 60904-1: Measurement of photovoltaic current-voltage characteristics
• IEC 60904-2: Requirements for reference solar devices
• IEC 60904-3: Measurement principles for terrestrial PV devices with reference spectral irradiance data
• IEC 60904-7: Computation of spectral mismatch error introduced in PV device testing
• IEC 60904-8: Additional parts addressing further PV measurement parameters

Keywords: IEC 60904-9, solar simulator performance, photovoltaic testing, PV device measurement, spectral distribution match, irradiance non-uniformity, temporal instability, solar simulator classification, IEC 60904 series, international photovoltaic standards