Introduction
Analysing the results of a single operation will already provide you with tons of insight, but comparing the results with previous operations can help prioritise and validate remedial actions.
💡 Note that historical analysis is only available on sites with a Digital Twin Basic or Advanced subscription active.
When is it useful to analyse over time?
Comparing results over time is mainly useful in two cases:
It can help identify problems that don't seem important right now, but that will become a problem soon. This is very useful for warranty claims as well.
It can help validate if remedial actions of last year had the desired effect.
As the first point might not be that straightforward, we can take a closer look. We'd recommend the following flow when prioritising anomalies:
Determine major problems
You can define the exact criteria yourself, but some problems will definitely require immediate action. Think about very high delta hotspots that pose a fire hazard or a major inverter outage.Gather claimable problems
While not all problems require immediate action, you always have to pay attention to your modules' warranty. If your warranty is about to run out, it's worth checking which modules are suffering from mild problems as well. If you have sufficient evidence, you might be eligible for a free replacement.
💡Historical evidence can be very powerful for a warranty claim. Even if the problem isn't severe enough according to the claim's guidelines, evidence that shows it's deteriorating can help claim more modules.
How to analyse results over time?
There are two tools that can help you analyse results over time:
Filters can help you find recurring or new anomalies of specific types.
Charts can help you analyse trends over time.
You can combine both tools to locate the anomalies that deserve extra attention.
Locate recurring anomalies using filters
When a Digital Twin Basic or Advanced subscription is active on your site and a previous operation exists, all anomalies will have a Detection History property. This property indicates if a problem existed on the module in the previous inspection or not.
Using the thermal anomaly filters, you can focus on issues that are either recurring or new.
💡 You can combine the Detection History filter with other filters, for example to find only recurring hotspots or new substring issues.
Identify trends using charts
A anomaly type trend chart is available under the site level reports tab and in chart mode of the latest operation (note you have to click on the history analysis box to see it). It shows how many anomalies of each type were found on your site over time.
💡 In the operation's chart mode, you can use filters to see the recurrence of anomalies matching specific criteria. This can help you spot the evolution of critical issues for example.
Using swipe compare to detect changes visually
In Solar Thermography Pro operations, you can visually compare the thermal layer using swipe compare. This can help identify if recurring issues are located on the same cells.
Things to watch out for
When comparing anomalies over time, it's important to know that different parameters can influence the results of an aerial thermography. Problems might appear less severe when there's less irradiance (sunlight) or the air temperature is lower.
If you want to accurately compare singular anomalies over time, it's important to normalise your thermography results. You can find more information in the article that's linked below.
Additional Resources
Analysing thermography results - A more general overview of how to analyse results of a thermography.
Filtering out anomalies - A video that explains how to use filters to locate specific anomalies.
Weather normalisation - A video that explains how weather data can be taken into account to facilitate historical analysis.