Overview
IEC 62805-1:2017 sets out an internationally recognized method for the measurement and calculation of the total haze and the spectral distribution of haze in glass used in photovoltaic (PV) modules. Published by the International Electrotechnical Commission (IEC), this standard is vital for ensuring the characterization and quality control of glass-particularly transparent conductive oxide (TCO) coated glass-employed in various PV technologies. Unlike general haze measurement standards, IEC 62805-1 specifically addresses the spectral properties of haze relevant to the performance of solar cells, making it critical for the solar energy and PV manufacturing industries.
Key Topics
- Purpose and Scope: Defines procedures for measuring total haze and the spectral distribution of haze in PV glass, with a wavelength range tailored to the operational spectrum of common PV devices (typically 280 nm to 1,250 nm).
- Applicability: Covers all glass types used in PV modules, including TCO-coated glass that functions as a substrate or cover glass in thin-film solar cells.
- Essential Terminology: Introduces precise definitions for terms such as total haze, spectral distribution of haze, and types of spectrometers used for measurement.
- Measurement Methods:
- Outlines the use of single-beam and double-beam spectrometers with integrating spheres.
- Specifies apparatus setup, calibration, and performance requirements for accurate haze measurement.
- Calculation Procedures: Includes formulas for determining the spectral distribution of haze at various wavelengths and for calculating the total haze across the relevant spectral range.
- Reporting Requirements: Requires detailed reporting of methods, apparatus specifications, test conditions, measurement data, and calculation results for full traceability and compliance.
Applications
IEC 62805-1:2017 is particularly significant in sectors using photovoltaic glass as a key component, such as:
- PV Module Manufacturing: Accurate measurement of haze impacts module efficiency, as haze values influence light scattering and, therefore, solar cell energy absorption.
- Quality Assurance: Ensures consistency and reliability in the optical properties of PV glass used in commercial solar modules.
- Research and Development: Supports the design and optimization of new solar cell technologies, such as thin-film PV modules and advanced TCO coatings, which benefit from controlled haze properties for improved performance.
- Certification and Specifications: Provides a reference method for certifying PV glass suppliers and for including clear, internationally recognized specifications in procurement contracts.
Related Standards
For comprehensive understanding and implementation, IEC 62805-1 should be used alongside other key international standards, including:
- IEC 60904-3:2016 – Photovoltaic devices – Part 3: Measurement principles for terrestrial photovoltaic (PV) solar devices with reference spectral irradiance data. This defines the reference spectrum for PV device testing.
- IEC TS 61836 – Solar photovoltaic energy systems – Terms, definitions and symbols. It standardizes key terminology used in PV technology.
- ASTM D1003-13 – Standard test method for haze and luminous transmittance of transparent plastics. Although not specific to PV glass, it provides foundational methodologies for haze measurement.
IEC 62805-1:2017 offers a standardized approach to measuring and reporting haze in photovoltaic glass, enhancing module consistency, supporting quality assurance, and underpinning advances in solar technology. By following this standard, manufacturers and laboratories can ensure that PV glass meets the specific optical performance needs of modern solar cells, driving innovation and reliability in the photovoltaics industry.