Introduction
It's not a secret that weather is an important factor when we talk about thermography of solar modules. The most optimal weather conditions to conduct thermal inspections on solar sites are clear and sunny days with low wind speeds.
For example, when there are a lot of clouds, the irradiance received by a solar module is low. That affects the amount of current produced and going through the module. That also means that it is harder to distinguish good from bad solar cells when doing thermal inspections.
That is also the main reason why the IEC standard states that you need a minimum irradiance of 600 W/m² to perform effective thermal inspections on solar modules. Not only irradiance, but also the air temperature and the windspeed will have an effect on the thermography.
Favourable weather conditions are necessary for producing the best thermal inspection data.
The platform allows you to:
Upload weather data from different sensor sources and combine them if needed.
Validate the environmental conditions from the inspection.
Consult the Normalised Delta Temperature property to make more informed decisions.
Compare severity of hotspots, based on the normalised delta temperature.
Report the weather details per anomaly.
Which environmental factors are supported?
The following table shows the different weather properties that you can find in the property list from every thermal anomaly.
Property | Unit | Supported Sources |
Wind Speed | meter/second [m/s] | Pyranometer, Satellite |
Wind Direction | degrees [°] | Pyranometer, Satellite |
Air Temperature | degrees Celsius [°C] or degrees Fahrenheit [°F] | Pyranometer, Handheld, Satellite |
Relative Humidity | percentage [%] | Pyranometer, Satellite |
Global Titled Irradiance (GTI) | Watt/square meter [W/m²] | Pyranometer, Handheld, Satellite |
Which data sources does Sitemark accept?
You can upload weather data that comes from a pyranometer or a handheld device. Simply said, a pyranometer is a device that measures solar irradiance from a hemispherical field of view on a flat surface. There are different pyranometer and handheld brands and models out there in the market that can measure weather properties. It is important to be able to export the data, as the recorded data can be used to add weather information to the anomalies.
Weather data from satellite sources is not supported yet. It is very challenging to get accurate data, because you need to have good knowledge of the geometry, orientation and tilt of the panels to get an accurate estimate of the Global Titled Irradiance coming from satellite sources.
How can I upload the weather data?
At any point in time, even when the operation has already been completed, users can upload their own weather dataset to their operations on the platform.
Sitemark Fuse will extract the relevant weather information from the uploaded dataset based on the time stamp in the anomaly and will save those weather details in the anomaly properties.
For the guide on how to upload your data, you can check out this support article.
ℹ️ If the user purchases the optional irradiance option from Sitemark, the pilot will upload irradiance data from his handheld device when uploading the photos. Please talk to your sales manager to make sure you have the right product and service ordered.