IEC 61701:2011

Overview

IEC 61701:2011 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies test sequences for salt mist corrosion testing of photovoltaic (PV) modules. This standard is critical for assessing the corrosion resistance of PV modules exposed to salt mist environments, particularly in marine or coastal locations where chloride salts like sodium chloride (NaCl) and magnesium chloride (MgCl₂) are prevalent.

Its primary objective is to evaluate the durability and reliability of different types of PV modules-including flat plate and concentrator photovoltaic (CPV) modules-under corrosive salt mist conditions. The standardized testing ensures PV modules maintain their electrical performance and integrity throughout their operational lifetime in harsh environments.

Key Topics

• Scope and Purpose
  Designed to simulate the effects of salt-laden wet atmospheres on PV modules, this standard is applicable to both permanent marine exposure and temporary corrosive atmospheres (such as deicing salts on roads). It evaluates corrosion on metallic parts and deterioration of non-metallic materials like coatings and plastics.

• Test Basis and Procedures
  IEC 61701:2011 bases its salt mist testing on IEC 60068-2-52 (salt mist, cyclic sodium chloride solution), which involves cycles of salt fog exposure followed by humidity storage under controlled temperature and relative humidity conditions. This cyclic test sequence more accurately reflects real-world corrosion mechanisms compared to previous editions relying on single exposure salt fog tests.

• PV Module Types Covered

  • Crystalline silicon PV modules
  • Thin-film PV modules
  • Concentrator photovoltaic (CPV) modules and assemblies

• Testing Components
  The standard integrates tests from IEC 61215, IEC 61646, IEC 62108, IEC 61730-2, and IEC 60068-2-52, covering aspects such as:

  • Bypass diode functionality
  • Electrical performance before and after testing
  • Visual and mechanical inspections
  • Corrosion effects on metallic and non-metallic materials

• Sample Requirements
  Three identical samples of the PV module model are used, with one serving as a control for comparison. For CPV modules, tests include primary and secondary optics when applicable. Smaller representative samples may be used if full-size modules cannot fit test chambers.

Applications

• Marine and Coastal PV Installations
  Provides essential assessment for PV modules intended for installation near seas and oceans, where continuous exposure to salt mist can cause rapid degradation.

• Roadside and Winter Salt Exposure
  Suitable for PV systems located near roadways treated with deicing salts, which create temporary corrosive conditions affecting module longevity.

• Quality Assurance and Certification
  Helps manufacturers meet rigorous type approval and design qualification requirements ensuring modules withstand environmental corrosion stresses.

• Product Development and Improvement
  Assists R&D teams in understanding corrosion resistance of different PV materials and designs to innovate more durable photovoltaic products.

• Comparison of PV Technologies
  Enables standardized evaluation across crystalline silicon, thin-film, and CPV technologies to select appropriate solutions based on environmental exposure risks.

Related Standards

• IEC 60068-2-52 – Environmental testing for salt mist, cyclic (sodium chloride solution)
• IEC 61215 – Design qualification for crystalline silicon terrestrial PV modules
• IEC 61646 – Design qualification for thin-film terrestrial PV modules
• IEC 61730-2 – PV module safety qualification and testing requirements
• IEC 62108 – Design qualification for concentrator photovoltaic modules and assemblies
• ISO/IEC 17025 – General requirements for the competence of testing and calibration laboratories

These normative references support IEC 61701 by providing detailed test methods or complementary criteria used during the salt mist corrosion testing sequences.

By adhering to IEC 61701:2011, stakeholders in the photovoltaic industry-including manufacturers, testing labs, and system designers-can ensure that PV modules meet internationally recognized standards for resistance to salt mist corrosion. This standard plays a vital role in enhancing the longevity, safety, and performance of solar power installations operating in corrosive environments worldwide.