Overview
IEC 62670-2:2015 is an international standard published by the International Electrotechnical Commission (IEC) that focuses on photovoltaic concentrators (CPV) and their performance testing, specifically in the context of energy measurement. This part of the IEC 62670 series defines minimum requirements and standardized testing methodologies for determining the energy output and performance ratio of CPV modules, arrays, assemblies, and full-scale power plants using an on-sun, measurement-based method.
The standard ensures a consistent approach to evaluating CPV system performance under realistic outdoor conditions by specifying mandatory measurements, data acquisition, processing methods, and key reporting parameters. IEC 62670-2:2015 complements earlier and forthcoming parts of the series to improve reliability, comparability, and transparency in CPV performance assessment.
Key Topics
- Scope and Application: Standardizes energy measurement techniques for CPV systems with a minimum geometric concentration ratio greater than 3×, requiring tracking systems.
- Measurement Methodology: Emphasizes on-sun testing leveraging direct normal irradiance (DNI), ambient conditions, and electrical power readings to calculate energy output.
- Mandatory Measurements:
- Direct normal irradiance
- Global plane of array irradiance
- Ambient air temperature
- Wind speed
- Electrical power or energy output
- Cold source temperature (for actively cooled CPV systems)
- Data Acquisition and Processing:
- Use of data acquisition systems (DAS) with specified sampling intervals.
- Integration of power measurements to calculate energy.
- Filtering and data validation practices to ensure accuracy.
- Performance Ratios: Defines calculation methods for both AC and DC performance ratios to assess system efficiency relative to theoretical energy production.
- Reporting: Establishes minimum reporting information to facilitate reproducibility and standard compliance verification.
- Annexes:
- Recommended data filtering techniques to remove erroneous data.
- Best practices for power plant energy measurement and reporting.
- Optionally derived parameters such as Energy Production Rate (EPR) and Capacity Factor (CF).
Applications
IEC 62670-2:2015 is essential for stakeholders involved in the design, installation, operation, and evaluation of CPV systems, including:
- CPV Module and Array Manufacturers: To provide standardized performance data and validate product efficiency claims.
- Power Plant Operators and Developers: For accurate on-site performance verification, operational optimization, and performance warranty assessment.
- Testing and Certification Laboratories: To conduct accredited energy measurements in compliance with international requirements.
- Researchers and System Designers: To benchmark and improve CPV technologies using reliable field data.
- Investors and Regulators: To assess the viability and expected yield of CPV projects based on standardized measurement data.
By employing this standard, the solar energy sector can ensure consistent energy output assessments, enabling better project comparisons, enhanced system reliability, and improved confidence in CPV energy performance metrics.
Related Standards
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IEC 62670-1: Photovoltaic Concentrators (CPV) – Performance Testing – Part 1: Standard Conditions
Defines the reference conditions for rating CPV modules and assemblies, forming a foundation for performance comparison.
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IEC 62670-3 (Under Development): CPV Power Assessment Methods
Focuses on power testing indoors and outdoors under standard conditions, complementing energy measurement techniques.
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ISO/IEC 17025: General Requirements for the Competence of Testing and Calibration Laboratories
Provides guidelines for maintaining quality and technical validity during testing procedures.
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ISO 8601: Data Formats for Dates and Times
Ensures consistency in data recording and timestamping during energy measurements.
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ISO 9060: Solar Energy Instrument Specifications
Covers classification and calibration of solar radiation measuring instruments that are mandatory for energy output calculations in CPV testing.
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JCGM 100: Guide to the Expression of Uncertainty in Measurement
Supports accurate uncertainty estimation in energy output and performance ratio calculations.
Conclusion
IEC 62670-2:2015 is an authoritative standard providing detailed procedures and requirements to measure the energy output and assess the performance ratio of photovoltaic concentrators. It is a critical resource for ensuring accuracy, consistency, and reliability in CPV energy measurements, facilitating industry-wide acceptance and optimization of this advanced solar technology. For professionals in solar energy, adhering to this standard is fundamental to achieving transparent performance verification and fostering the growth of CPV power generation worldwide.