The Raptor Maps application enables you to review infrared images associated with anomalies identified during site inspection. The IR image shows a higher temperature for the anomalous area or component compared to adjacent areas or components. This is because defects dissipate solar energy as heat rather than converting it to current.
More serious defects have higher temperature differentials. Many manufacturers consider a temperature differential greater than 20 degrees evidence of a defective module, where the hotter module is defective. Anomalies are not always stable and can vary from one day to the next, depending on the conditions at the time of inspection.
Anomalies showing smaller temperature differentials, especially less than 10 degrees, may not require immediate attention but generally continue to degrade over time.
Common causes of anomalies include:
- Damage during installation
- Shading
- Soiling
- Vegetation
- Cracking
- Manufacturing defect
- Weather events (lightning, hail, wind)
- Suboptimal grounding
- Module degradation (for example, delamination)
- Fuse or connector failure (for strings)
An RGB image can assist in determining the cause of the anomaly. For example, the RGB image confirms vegetation as the cause of this multi cell anomaly:
The value of a solar inspection is that it provides insight into the impact of anomalies on power production.
Due to solar site design, some anomalies have bigger impact than others. A solar site uses silicon solar cells to convert the energy of sunlight into electricity. The power generated is made available to the grid by means of strings, combiners, and finally inverters, which feed into the point of interconnection.
When assessing anomaly impact on power production, it’s important to consider that outages of components such as combiners and inverters result in a greater reduction in power production than individual cells.
Raptor Maps uses a power factor to take into account that, for example, a string outage will have much greater impact on overall power production than a cell outage.
For more information, refer to Calculating impact of anomalies and power factors.
Raptor Maps analysis checks for all of the following anomalies:
Ballast
A ballast consists of concrete blocks used to secure an array of solar modules to the ground or the roof.
A ballast anomaly indicates a broken ballast.
Cell
Hot spot occurring with square geometry in single cell
Cell low
Cell anomaly, where the temperature of an anomalous area is less than 10˚C higher than adjacent areas
Cell medium
Cell anomaly, where the temperature of an anomalous area is 10-20˚C higher than adjacent areas
Cell high
Cell anomaly, where the temperature of an anomalous area is 20˚C higher than adjacent areas
Cell multi
Hot spots occurring with square geometry in multiple cells
Cell multi low
Cell multi anomaly, where the temperature of an anomalous area is less than 10˚C higher than adjacent areas
Cell multi medium
Cell multi anomaly, where the temperature of an anomalous area is 10-20˚C higher than adjacent areas
Cell multi high
Cell multi anomaly, where the temperature of an anomalous area is 20˚C higher than adjacent areas
Combiner
A combiner combines many strings into a larger flow of DC (direct current).
A combiner anomaly shows fault in contiguous strings matching the inverter layout.
Cracking
Module anomaly caused by cracking on module surface
Delamination
Module anomaly due to compromised adhesion between glass, encapsulant, active layers, and/or back layers. More common with thin film modules
Diode
A bypass diode provides a current path around a faulty cell or module.
A diode anomaly indicates as activated bypass diode, typically 1/3 of module.
Diode multi
Multiple activated bypass diodes, typically affecting ⅔ of module.
Hot spot
Anomalous spot on a cell
Hot spot low
Hot spot, where the temperature of the anomalous area is less than 10˚C higher than adjacent areas
Hot spot medium
Hot spot, where the temperature of the anomalous area is 10-20˚C higher than adjacent areas
Hot spot high
Hot spot, where the temperature of the anomalous area is 20˚C higher than adjacent areas
Hot spot multi
Multiple hot spots on a thin film module
Hot spot multi low
Hot spot multi, where the temperature of the anomalous area is less than 10˚C higher than adjacent areas
Hot spot multi medium
Hot spot multi, where the temperature of the anomalous area is 10-20˚C higher than adjacent areas
Hot spot multi high
Hot spot multi, where the temperature of the anomalous area is 20˚C higher than adjacent areas
Internal short circuit
Multiple cell anomalies as a result of a short circuit
Inverter
An inverter converts the DC current of many combiners into usable AC.
An inverter anomaly shows fault in contiguous strings matching the inverter layout.
Junction box
A junction box is an enclosure on the module which connects the PV strings.
A junction box anomaly is a hot spot at the junction box location on the module.
Junction box low
Junction box anomaly, where the temperature of the anomalous area is less than 10˚C higher than adjacent areas.
Junction box medium
Junction box anomaly, where the temperature of the anomalous area is 10-20˚C higher than adjacent areas
Junction box high
Junction box anomaly, where the temperature of the anomalous area is 20˚C higher than adjacent areas
Missing
Module is present on as-built but missing from PV system
Module
Entire module is heated
Shadowing
Sunlight obstructed by vegetation, man-made structures, or adjacent rows
Soiling
Dirt, dust, or other debris on surface of module
Spare module
Module is present on as-built and marked as offline
String
A string consists of an individual set of modules connected in series.
A string anomaly shows fault in contiguous modules matching the string layout.
Tracker
Tilt tracker position affecting power production
Vegetation
Modules blocked by vegetation