Photovoltaic power plant inspection report

*(1) Anomaly: Number of occurrences of a given anomaly type.
*(2) Modules: Number of modules affected by the given anomaly type.
*(3) Estimated Power Loss (kW): The estimated power loss is defined as the product of the number of affected modules, the plant’s peak power (STC), and the anomaly-specific performance impact factor (on a scale from 0 to 1).
*(4) Estimated Power Loss (%): The estimated power loss expressed as the ratio of the lost power to the plant’s total capacity, shown in percentage terms.
*(5) Estimated Annual Power Loss (kWh): The estimated annual energy loss in kilowatt-hours, calculated as the power loss multiplied by the number of solar hours per year.
*(6) Estimated Annual Financial Loss (CZK): The estimated annual financial loss is calculated based on the annual energy loss in kilowatt-hours multiplied by the price per kilowatt-hour. The price per kilowatt-hour is determined according to the feed-in tariff provided by the client for the purpose of this calculation.

For more information about individual anomaly types, please refer to the end of this document.

Course and Processing of Aerial Thermographic Measurement

Analyzed Anomalies

1. Cell: Local thermal anomaly at the level of a single PV cell, indicating a potential defect, typically caused by manufacturing faults, material degradation, or mechanical damage.
2. Cell Multi: Multiple thermal anomalies distributed across several adjacent cells of one module, often signaling a more extensive structural defect or degradation.
3. Circuit: Fault in the electrical circuit, manifested by outage or underperformance of multiple strings, related to connection or insulation issues.
4. Combiner: Anomaly caused by a defect at the point of combining multiple strings into one DC flow, often linked to poor connections, cable degradation, or failure of protective components.
5. Cracking: Occurrence of micro-cracks or macro-cracks in the glass or laminated structure of the module, leading to localized overheating, reduced performance, and risk of further degradation.
6. Damaged: Mechanical deformation of the module, including bending, displacement, physical damage, or extensive cracking, which may cause significant power losses and increased safety risk.
7. Delamination: Separation of the glass, encapsulant, or active layer of the module, leading to degradation of protective properties, higher susceptibility to moisture ingress, and reduced performance.
8. Diode: Activation of a bypass diode as a result of a failed cell or module, indicating the presence of a serious localized defect affecting part of the production chain.
9. Helix Damage: Permanent deformation of modules or supporting structures caused by mechanical twisting of the tracker, usually due to a malfunction in movement control.
10. Hot Spot: Small area with significantly higher temperature compared to its surroundings, indicating faulty connections, cell degradation, or partial shading, with a high risk of further defects.
11. Hot Spot Multi: Occurrence of multiple hot spots within a single module, typically in thin-film panels, indicating more extensive structural damage.
12. Internal Short Circuit: Anomaly resulting from an internal short circuit in the module, causing localized heating and significant performance reduction.
13. Inverter: Malfunction of the inverter converting DC into AC current, manifested by non-functionality of connected strings and affecting large parts of the system.
14. Junction Box: Thermal anomaly at the connection point of strings on the module, often indicating faulty joints, corrosion damage, or overheating of electrical contacts.
15. Missing Module: Physically absent module that was documented as installed according to project records, or removed without documentation update.
16. Module: Overall thermal anomaly at the level of the entire module, often indicating bypass diode failure, internal damage, or degradation of the whole unit.
17. Physical Obstruction: Presence of a foreign object (e.g., leaves, stones, snow) on the panel surface causing shading and localized performance loss.
18. Reverse Polarity: Electrical connection with incorrect polarity, leading to power loss, potential equipment damage, and fault risk.
19. Shading: Blocking of solar irradiance by vegetation, structures, or other objects, directly reducing energy production efficiency.
20. Soiling: Accumulation of dust, dirt, bird droppings, or other debris on the panel surface, causing uneven irradiance and reduced performance.
21. String: Set of PV modules connected in series, where faults in individual modules or connections affect the performance of the entire group.
22. Tracker Tilt: Incorrect tracker angle setting, reducing the system’s ability to optimize energy production during the day.
23. Underperforming String: String showing significantly lower temperature difference (and thus output) compared to neighboring strings, usually indicating partial defects.
24. Vegetation: Shading of modules by vegetation (grass, shrubs, trees), reducing direct solar irradiance and system efficiency.