IEC 61724 PDF
The standard for PV system performance monitoring has been revised. The new version, released February , defines “accuracy classes”. Abstract — After a PV system is installed, periodic analysis is necessary to track how measured performance meets expectations. IEC outlines methods . The IEC standard for PV system performance monitoring has been revised. This is relevant for system owners, O&M managers.
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IEC what’s it all about? | PV Tech
It does so by establishing accuracy classes for monitoring systems. The class is not only determined by the hardware that is used, but also by quality checks and measurement procedures.
Once every 2 years.
It addresses sensors, installation, and accuracy for monitoring equipment in addition to measured parameter data acquisition and quality checks, calculated parameters, and performance metrics. You should at least do all of the below: In conformity declarations, providers must state the accuracy class of the measurement. It outlines equipment, methods, and terminology for performance monitoring and analysis of photovoltaic PV systems.
The new version of the standard is fundamentally different from the version. Both standards define Class A, B and C but with a different meaning. The first edition of IEC Introduction The first edition of IEC Heating and ventilation of solar radiation sensors keeps the glass temperature above dewpoint and free from dew and frost deposition.
The following tables offer an overview of the main elements of the IEC monitoring classification system, its requirements for solar radiation measurement and which pyranometers comply in which accuracy class. The version of the standard recognises that the solar irradiance measurement is one of the weakest links in the measurement chain. For pyranometers, the following costs are associated with Class A: Why heating and ventilation?
Delft – The Netherlands T: It also defines cleaning and calibration intervals for pyranometers. It specifies for each class of monitoring system the pyranometer class that must be used, including required instrument ventilation and heating, azimuth and tilt angle accuracy.
The standard also defines requirements for measurement of module- and air temperature, wind speed and direction, soiling ratio, and AC and DC current and voltage. It shows requirements for solar radiation measurements and which pyranometers comply. It is no use having only one or a few instruments Class A. When facing the sky on a clear night, glass temperature tends to go below dewpoint, so that water condenses on the dome.
It now has been updated. The standard for PV system performance monitoring has been revised. At least 6724 per week.
Photovoltaic system performance monitoring — Guidelines for measurement, data exchange and analysis —dates from It is too costly to obtain a Class A status: Class B medium accuracy. Class A means great care for the maintenance of your pyranometers A survey showed that the main reason for most companies not idc aim for a Class A status for IEC, is the cost-benefit analysis they made.
Emerainville – France T: Pyranometer domes are made of glass. Class C basic accuracy. To achieve this, dew, frost, soiling and instrument deposition as such should be prevented, and customers have to do good product maintenance.
You should at 61742 do all of the below:. Class A high accuracy.
Quick facts on the IEC standard for PV stakeholders – Kipp & Zonen
The new scope not only defines the measuring system components and uec as in the versionbut also aims to keep measurement errors within specified limits. The solution with true air ventilation, not air circulation. This memo offers comments on consequences of the new standard concerning the selection of pyranometers. The standard contains detailed specifications at monitoring system component level.
IEC 61724-1: what’s it all about?
The new standard includes: Figure 1 frost and dew deposition: The classes A, B and C are site requirements; all individual onsite measurement instruments have to be Class A, in order to obtain a Class A status of the site. There are two reasons for the extra steps prescribed by IEC to comply with an optimal Class A: This significantly increases the reliability of the measured data.
A survey showed that the main reason for most companies not to aim for a Class A status for IEC, is the cost-benefit analysis they made.