There is a wide range of international standards which should be considered when working with solar energy, PV plant operation and plant maintenance.
Image Credit: OTT HydroMet - Solar Energy
A number of these standards are applicable to the earlier phases of design, procurement and construction, while the levels and standards chosen for a specific solar project will impact the choice of products used to monitor solar irradiance and environmental conditions.
In order to elucidate this complex subject, Kipp & Zonen has summarized a number of ISO and IEC standards relevant to weather monitoring in a white paper entitled ‘Solar Energy International Standards’.
IEC 61724-1 PV System Performance Monitoring
The IEC 61724-1 PV standard is responsible for defining terminology and classifying the equipment and methods necessary to monitor and analyze the performance of solar energy plant systems - ranging from irradiance input to AC power output.
The white paper outlines the way in which IEC 61724-1 applies to the specification and maintenance of equipment designed to monitor irradiance and a range of other weather parameters.
ISO 9060 Pyranometers and Pyrheliometers
Kipp & Zonen is the leading manufacturer of pyranometers and pyrheliometers, meaning that the company works with ISO 9060 standards regularly. ISO 9060 is entitled ‘Solar energy - Specification and classification of instruments for measuring hemispherical solar and direct solar radiation’.
This standard defines and outlines the use of a pyranometer for measuring global horizontal or tilted irradiance (GHI and POA) and, when shaded, DHI. The standard also defines and outlines the use of a pyrheliometer for measuring DNI.
ISO 9060: 2018 Update
The original 1990 edition of the standard was revised and published in November 2018. The primary difference between these two editions is that the classes of pyranometer have been altered from Secondary Standard, First Class and Second Class to the new A, B and C standards.
Kipp & Zonen’s white paper provides detailed information on the update, defining the new ‘spectrally flat’ terminology and outlining and how Kipp & Zonen pyranometers are classified in relation to the update.
ISO Calibration Standards
A range of international standards are related to solar energy. These include IEC 61724-1 - which requires that pyranometers be calibrated in line with ISO 9846:1993 or ISO 9847:1992.
The white paper details both indoor and outdoor calibration options, as well as explaining how to conduct a site confidence check to evaluate pyranometer performance between calibrations.
ISO/IEC 17025 Accreditation
This standard refers to and encompasses the ‘General requirements for the competence of testing and calibration laboratories’.
The white paper explores this standard, using examples from Kipp & Zonen’s radiometric laboratory at the factory in Delft, The Netherlands. This laboratory is accredited for the sensitivity calibration of pyranometers and pyrheliometers.
This information has been sourced, reviewed and adapted from materials provided by OTT HydroMet - Solar Energy.
For more information on this source, please visit OTT HydroMet - Solar Energy.