A pyranometer typically consists of a flat surface that is designed to absorb the incident radiation.
Underneath is a sensor that measures the intensity of the incoming light.
Pyranometers measure the total solar radiation, also known as global radiation. Global radiation is made up of the sum of direct and indirect solar radiation.
The measured irradiation is normally expressed in units such as watts per square metre (W/m²) or Kwh/m² (kilowatt hour per square metre). These units indicate how much energy per unit area per unit time hits the surface.
In order to check the performance of a photovoltaic system, at least two parameters are always recommended – on the one hand the parameter that the system itself emits and another for testing. This is the only way to really ensure that your solar system is working efficiently. If you only rely on the power output of the solar system, you may discover any performance impairments such as dirt or defects too late.
This is where the pyranometer comes into play: The pyranometer measures the total solar radiation. This results in a characteristic curve that provides information about this global radiation.
If this characteristic curve deviates from the characteristic curve of the photovoltaic system, this is an indication of a possible defect in the system.
KNX pyranometers offer a decisive advantage at this point: you can set the corresponding limit value in the KNX system. If this is exceeded, you will receive an alarm via the system.
Online weather services obtain their data from local weather stations. However, these stations may be several kilometres away from your location. The cloud that is currently over your photovoltaic system may not even be detected by the weather station further away.
Therefore, data from online weather services should be treated with caution and is not a reliable source for checking your photovoltaic system. A pyranometer, on the other hand, provides you with the current values for your location in real time and is therefore the most reliable source of radiation data.
Are you using a pyranometer for your project? Write to us and let us know what experiences you have had with pyranometers.
We look forward to your feedback!
