Overview
IEC 62862-3-6:2026 is an international standard developed by the International Electrotechnical Commission (IEC). It addresses the durability of silvered-glass reflectors used in solar thermal electric plants, with a focus on laboratory test methods and assessment criteria. These reflectors are critical components in concentrating solar technologies, where precise and long-lasting reflectivity is essential for plant efficiency and performance.
This document specifies accelerated aging test procedures to evaluate the durability of reflectors composed of a float-glass substrate with a silver reflective layer, which is further protected by copper and various anticorrosive paint systems. The standard ensures that products meet high performance requirements necessary for demanding solar environments.
Key Topics
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Accelerated Aging Tests: The standard outlines a comprehensive set of laboratory tests simulating long-term environmental exposure. These include:
- Neutral salt spray (NSS)
- Copper-accelerated acetic acid salt spray (CASS)
- Condensation exposure (COND)
- Thermal cycling and humidity (TCH)
- Damp heat testing (DH)
- UV and humidity exposure (UVH)
- Abrasion and sand erosion
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Test Sample Requirements: Reflector samples must be at least 10 cm × 10 cm. At least one original edge from manufacturing must be retained, especially for corrosion assessment.
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Measurement and Assessment:
- Methods for visual inspection and quantification of defects (corrosion, discoloration, delamination)
- Reflectance measurement-both hemispherical and specular-before and after exposure, with criteria for allowable degradation
- Clear acceptance criteria for each accelerated aging test
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Comprehensive Reporting: Guidelines detail what information and results must be included in test reports to ensure transparency, repeatability, and comparability.
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Adaptability: Annexes provide guidance for applying these methods to reflector types of different compositions and correlate accelerated test outcomes with real-world, outdoor exposure scenarios.
Applications
IEC 62862-3-6:2026 serves manufacturers, developers, testing laboratories, and project stakeholders in solar thermal power generation. Key applications include:
- Product Qualification: Enables consistent comparison of reflector durability for procurement and supply chain assurance.
- Quality Control: Assists manufacturers in verifying that silvered-glass reflectors maintain their optical and physical performance over expected operational life in solar fields.
- Performance Assessment: Supports developers and plant operators in meeting both technical and warranty requirements, reducing the risk of premature failure.
- R&D and Innovation: Facilitates the development of new reflector materials and protective coatings by providing standardized methods for accelerated durability assessment.
- Regulatory Compliance: Ensures that reflectors meet internationally recognized criteria, streamlining project approvals and contributing to risk mitigation.
Related Standards
Implementing IEC 62862-3-6:2026 will often involve referencing related international standards, including:
- ISO 9227 – Corrosion tests in artificial atmospheres (salt spray tests)
- ISO 6270-2 – Paints and varnishes (determination of resistance to humidity)
- ISO 16474-3 – Laboratory exposure methods to UV lamps
- IEC 62108 – Concentrator photovoltaic (CPV) modules and assemblies - design qualification and type approval
- IEC TS 62862-1-1 – Solar thermal electric plants - Terminology
- IEC 60904-3 – Measurement principles for photovoltaic devices
Summary
IEC 62862-3-6:2026 provides the solar thermal industry with harmonized, reliable test methods to evaluate and assess the durability of silvered-glass reflectors. Adoption of the standard enhances performance transparency, supports quality improvements, and enables effective risk management across the solar supply chain. By adhering to these laboratory test methods, stakeholders can ensure their technologies deliver long-term, sustainable, and efficient solar thermal power generation.