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.

It does so iex establishing accuracy classes for monitoring systems. Figure 1 frost and dew deposition: To achieve this, dew, frost, soiling and instrument deposition as such should be prevented, and customers have to do good product maintenance. The standard for PV system performance monitoring has been revised. It is too costly to obtain a Class A status: 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.

The standard contains detailed specifications at monitoring system component level. Class B medium accuracy. For pyranometers, the following costs are associated with Class A: In conformity declarations, providers must state the accuracy class of the measurement. Heating and ventilation of solar radiation sensors keeps the glass temperature above dewpoint and free from dew and frost deposition.

Delft – The Netherlands T: Class A high accuracy.

You should at least do all of the below:. It shows requirements for solar radiation measurements and which pyranometers comply.

Quick facts on the IEC standard for PV stakeholders – Kipp & Zonen

It also defines cleaning and calibration intervals for pyranometers. Why heating and ventilation? This memo offers comments on consequences of the new standard concerning the selection of pyranometers. The standard also defines requirements for measurement of module- and air temperature, wind speed and direction, ifc ratio, and AC and DC current and voltage. It addresses sensors, installation, and accuracy for monitoring equipment in addition to measured parameter data acquisition and quality checks, calculated parameters, and performance 6124.

Quick facts on the IEC 61724-1 standard for PV stakeholders

This significantly increases the reliability of the measured data. The first edition of IEC The following tables offer an overview of the main elements of the IEC 16724 classification system, its requirements for solar radiation measurement and which pyranometers comply in which accuracy class.

It is no use having only one or a few instruments Class A. The solution with true air ventilation, not air circulation. The new scope not only defines the measuring system components and procedures as in the versionbut also aims to keep measurement errors within specified limits. The version of the standard recognises that the solar irradiance measurement is one of the weakest links in the measurement chain. Emerainville – France T: 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.

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. The new standard includes: Photovoltaic system performance monitoring — Guidelines for measurement, data exchange and analysis —dates from When facing the sky on a clear night, glass temperature tends to go below dewpoint, so that water condenses on the dome.

It now 61274 been updated.

Both standards define Class A, B and C but with a different meaning. Class C basic accuracy.

The new version of the standard is fundamentally different from the version. Introduction The first edition of IEC