Find the hotspot before it finds your yield report.
Radiometric thermal + RGB drone survey detects hotspots, PID, bypass diode failure and micro-cracks that manual walkthroughs miss then tracks every defect to resolution on a live dashboard, not just a PDF. DGCA-certified. IEC 62446-3 compliant. Zero shutdown.
5+ lakh
Drone Flights Completed
34+ GW
Solar Assets Inspected
2.3+ lakh
Hectares Surveyed
210+ Cr
Saved in Operational Costs
13,000+
Rooftop Surveys Completed
What Is It
Drone Solar Panel Inspection
Drone solar panel inspection also called aerial thermography for solar PV, or UAV photovoltaic inspection uses radiometric thermal UAVs to scan entire arrays from above, capturing the temperature anomalies that indicate module-level defects. A DGCA-licensed pilot flies a calibrated grid pattern over each panel row, recording thermal and visible-light imagery in the same pass. The processed output is a geo-tagged defect map, an IEC 62446-3 compliant report, and uniquely at Lesoko. A live dashboard your team can log into.
Manual walkthroughs catch surface damage only. I-V curve tracing finds electrical faults but needs partial shutdown and heavy field time at scale. Aerial thermography covers a utility-scale asset in a fraction of the time, surfacing the defects both older methods routinely miss while the plant keeps generating.
The Gap
What manual inspection and SCADA both miss
Manual inspection works for post-storm visual assessment. It does not catch early-stage hotspots, PID degradation, or bypass diode faults across thousands of modules and string-level underperformance rarely shows up in SCADA until the cumulative loss is already operationally significant.
Why the loss stays invisible
Unresolved bypass diode failures cause progressive yield loss that compounds for months before SCADA reporting triggers action. Field inspection at scale carries real safety exposure too rooftop access requires fall protection and permit-to-work processes most O&M teams would rather avoid running routinely.
Without module-level, geo-tagged documentation, lender audits and manufacturer warranty claims lack the evidence base they require which is exactly the gap a radiometric thermal survey closes.
Radiometric vs Non-Radiometric
Radiometric sensors record an absolute temperature value per pixel, enabling defect classification by exact temperature differential. Lesoko deploys 640×512 resolution sensors with 0.05°C thermal sensitivity, capturing heat anomalies invisible to standard cameras.
Non-radiometric thermal cameras only show relative heat patterns and cannot produce IEC 62446-3 compliant output. The distinction that decides whether a report is acceptable to a lender, insurer, or independent technical auditor.
Process
How the inspection process works
Six operational steps from pre-flight planning to report delivery. Every stage is designed around one constraint: zero production downtime.
Pre-Flight Planning
Survey date confirmed with the site representative, DGCA no-fly zone check, weather-window verification, and flight-path design against the array layout.
Thermal + Visual Capture
RGB mapping at 80% front / 70% side overlap, ~6.5 m/s. Thermal mapping at the same overlap ratios, ~1.7 m/s, altitude set by roof or array height. Both datasets geo-tagged at module level.
Site Risk Assessment
On-site toolbox talk with client personnel, blocks/trackers requiring inspection re-confirmed, obstacle survey (altitude raised 15 m above any obstruction).
Defect Analysis
Engineer-led thermal anomaly detection and IEC 62446-3 severity classification. Visible-light imagery is overlaid on thermal data to eliminate soiling-driven false positives before the register is finalised.
Flight Execution
Licensed pilot flies under IEC 62446-3 irradiance conditions (600+ W/m², or panel temperature above 30°C). Flights parallel to panel rows with a 10 m overlap between KML boundaries.
Report + Dashboard Delivery
Engineer-verified output within 24 hours: geo-tagged defect maps, maintenance prioritisation sheets, executive dashboard, and live access to the Lesoko defect-tracking platform.
Defect Detection
Defects detected by aerial thermography
Radiometric thermal sensors identify twelve distinct fault categories across Lesoko’s inspection history. Every one causes measurable production loss or safety risk, and none are visible to the naked eye until they’ve already compounded.
Hotspot
Multiple hotspots
String Reverse Polarity
Open Circuit
Shadow & Shading
Damage
Dust & Soiling
Vegetation Overgrowth
Bird Droppings
Key Benefits
Why Solar Asset Owners Choose Aerial Thermography
Reasons why O&M managers, EPC heads, and IPP procurement teams specify Lesoko for their solar PV inspection programmes.
Lender-grade documentation
Geo-tagged defect evidence and IEC 62446-3 documentation formatted for direct use in technical due diligence.
Module-level GPS tagging
Every anomaly geo-tagged with exact coordinates so maintenance teams locate defects without re-inspection.
Live defect dashboard
Track every defect from detection through resolution not a one-time PDF that goes stale the day it's opened.
Preventive, not reactive
Scheduled surveys catch defects before they compound well ahead of the SCADA alert that signals loss already accrued.
Zero production downtime
Panels stay energised throughout the survey. A technical requirement for accurate defect detection, not a constraint.
₹210+ Cr proven ROI
Operational savings enabled across Lesoko's inspection portfolio, measured against revenue lost to unresolved anomalies.
Radiometric, IEC 62446-3 output
Temperature-accurate data (not visual-only imagery) meeting the sensor and documentation standard lenders require.
24-hour engineer-verified reports
Industry standard turnaround is 3–7 days. Lesoko delivers within 24 hours of flight completion, every time.
Technical Methodology
Inspection Methodology
Inspections are scheduled during peak irradiance windows 600+ W/m² is the minimum threshold for reliable defect detection. Thermal sensors undergo radiometric calibration before each session; ambient temperature, wind speed, and humidity are logged throughout the flight.
Ground sampling distance (GSD) is calibrated per site flight altitude is adjusted to achieve sub-5 cm/pixel resolution at module level, enabling individual cell defect identification rather than row-level anomaly detection only. Flight operations are suspended when wind speed exceeds 8 m/s beyond this threshold, radiometric sensor accuracy and UAV flight stability are both compromised.
Post-flight, thermal and visible-light imagery is processed into georeferenced orthomosaics using photogrammetry software. Defect classification follows IEC 62446-3 severity tiers. Engineer-led thermal anomaly detection eliminates false positives before the defect register is finalised. Every anomaly is reviewed by a qualified engineer before entering the final report.
Site-Specific Variables That Affect Thermal Data Quality
Soiling False Positives
Soiling deposits closely resemble early-stage hotspot defects in thermal imagery. Engineers overlay visible-light imagery over thermal data to eliminate soiling-induced false positives before the defect report is issued.
Tracker Tilt & Single-Axis Systems
Single-axis tracker panels require inspection at fixed tilt angles during peak irradiance. Tracker position is coordinated with plant operations before flight scheduling on all tracker-equipped sites.
Sun Angle & Irradiance Timing
Radiometric data quality degrades when sun angle is below 30° from horizontal. Inspection flights are scheduled around peak irradiance windows typically mid-morning to early afternoon.
Inverter Mismatch Overlap
Inverter mismatch signatures can overlap with electrical fault thermal patterns. All Lesoko reports include engineer-reviewed classification before final defect register issuance to distinguish these accurately.
Who This Is For
Built for the people who answer for plant performance
Solar O&M Managers
- Responsible for asset health, maintenance scheduling and yield optimisation across operational sites
- Manual inspection leaves coverage gaps and documentation weaknesses at utility scale
- Geo-tagged defect reports and the live dashboard slot into existing maintenance workflows
- Preventive defect resolution before cumulative yield loss triggers a SCADA alert
EPC Heads (Renewable Energy)
- Module-level documentation for commissioning sign-off, lender acceptance and warranty validation
- Radiometric TIFF and orthomosaic outputs meet standard EPC handover requirements
- Reports formatted for lender technical due diligence, including IEC 62446-3 documentation
- 24-hour turnaround supports tight commissioning timelines where delays carry penalty clauses
IPPs & DISCOMs
- Consistent vendor quality and consolidated reporting across multi-state portfolios
- Standardised deliverables across all assets same report format for every site regardless of state
- Single-vendor structure reduces procurement overhead across a multi-site programme
- Portfolio scheduling coordinated to optimise mobilisation and per-MW cost
Coverage across every major solar cluster
Lesoko deploys within 48 hours for sites above 10 MW. Completed inspection projects span Tamil Nadu, Karnataka, Gujarat, Rajasthan, Maharashtra, Andhra Pradesh and Telangana including Charanka (Gujarat), Bhadla (Rajasthan), Pavagada (Karnataka), Kurnool Ultra Mega Solar Park (Andhra Pradesh) and the Kamuthi Solar Power Project (Tamil Nadu).
Same-day deployment is available in Chennai, Bengaluru and Hyderabad.
Regional note: arid vs coastal sites
Dust accumulation patterns differ sharply between arid sites (Rajasthan, Gujarat) and coastal installations (Tamil Nadu, Kerala). Arid sites see higher soiling false-positive rates; coastal and floating sites carry elevated junction box corrosion and bird-drop risk. Inspection protocols are adjusted per region.
Monsoon season restrictions
Drone operations across peninsular India are restricted June–September due to monsoon wind and rainfall. Pre-monsoon (March–May) and post-monsoon (October–November) windows deliver the most operationally useful data.
- Gujarat
- Rajasthan
- Tamil Nadu
- Karnataka
- Maharashtra
- Andhra Pradesh
- Madhya Pradesh
- Uttar Pradesh
- Odisha
- Punjab
- Haryana
- Telangana
- Bihar
- Jharkhand
- Chhattisgarh
- West Bengal
- Kerala
- Assam
Pricing
Inspection cost and pricing structure
Drone solar panel inspection pricing is project-specific. No two sites share identical requirements. Larger sites benefit from lower per-MW cost due to deployment efficiency and multi-site portfolios within a region can reduce costs further.
Sites within the same state or region can be bundled into a single mobilisation reducing per-MW cost considerably across the portfolio. Inspection spend is typically a small fraction of the operational savings enabled by early defect detection. ₹210 Cr+ in operational savings has been enabled across Lesoko’s inspection portfolio measured by early defect resolution against estimated revenue loss from unresolved production anomalies. Inspection reports are formatted for direct use in lender technical due diligence, reducing documentation overhead for EPC and IPP procurement teams.
Pricing variables that determine inspection scope and cost
- MW Capacity: Larger sites benefit from lower per-MW cost. Economies of scale apply above 10 MW.
- Terrain & Access: Remote or hilly terrain increases logistics overhead. Restricted airspace adds lead time.
- Report Depth: Standard defect list vs full radiometric TIFF + orthomosaic + geo-tagged dataset + dashboard access.
- Travel Requirements: Remote sites in Rajasthan and Gujarat require multi-day deployment. Same-state bundling reduces per-MW cost.
- Turnaround Timeline: Standard 24-hour report delivery. Expedited same-day processing available for urgent requirements.
- Portfolio Bundling: Sites within the same state bundled into a single mobilisation significantly reduces per-MW cost at scale.
Measurable Impact.
A 600KW rooftop solar power plant was inspected after reporting a steady drop in output. Regular dust accumulation was the primary suspected cause. Lesoko's drone flew for just 1.5 hours and delivered cell-level defect mapping across all 1,430 modules — enabling the O&M team to take same-day action.
Outcomes Achieved
Defect Breakdown — % of 600KW
Solar Panel Inspections Video Coverage
Our Amazing Clients
What Solar Plant Operators Say
Deliverables
What Every Inspection Includes
Defect Layout (AutoCAD)
KML Report
Cumulative Report
Defect Report (Excel)
Inspection Map
Project Summary
Get Free Quote in 24 Hours
Phone/ Whatsapp
+91 78457 26375/ 7845726374
Email Us
sales@lesoko.in
Head Office
Get Your Inspection Quote
Frequently Asked Questions
Drone thermal inspection detects hotspots, multiple hotspots, bypass/strip diode failure, module hotspots, string reverse polarity, open circuits, PID, micro-cracks, soiling, shadow and shading, physical damage, bird droppings, vegetation encroachment and water ingress. Radiometric sensors detect temperature differences invisible to the naked eye, identifying significantly more fault types than manual visual inspection or non-radiometric cameras.
Both. Every inspection is delivered as a full PDF/Excel report plus access to Lesoko’s client dashboard, where defects are geo-tagged on an inspection map, filterable by severity and status, assignable to maintenance teams, and trackable from Defective through In Progress to Resolved across every inspection cycle.
Pricing is determined by MW capacity, terrain complexity, travel requirements, report depth and turnaround timeline. Utility-scale farms above 50 MW benefit from lower per-MW rates due to deployment efficiency, and sites within the same state can be bundled into a single mobilisation to reduce cost further. Contact Lesoko for a project-specific quote within 24 hours.
No. Aerial thermography operates while panels remain fully energised and under load. This is a technical requirement, not a constraint. Hotspots, bypass diode failures and PID signatures only produce a detectable heat differential when the module is under electrical load; a de-energised panel produces no thermal differential at all. This eliminates the revenue loss associated with shutdowns some traditional methods require.
Annual aerial thermography is the minimum recommended frequency for utility-scale assets. High-capacity farms above 100 MW benefit from bi-annual surveys, and post-storm or post-hail inspections should be triggered by the event itself regardless of the scheduled cycle. Early detection prevents compounding yield loss and strengthens lender audit documentation.
IEC 62446-3 is the international standard governing thermographic inspection of photovoltaic systems. It defines minimum irradiance thresholds (600+ W/m²), maximum wind speed and cloud cover, and required inspection-report documentation. Reports produced under IEC 62446-3 protocols are recognised by lenders, insurance underwriters and independent technical auditors. Non-compliant reports regardless of image quality may be rejected in lender audit processes.
Procurement teams evaluating vendors for lender-audit-grade inspections should require a sample report before contract sign-off to verify compliance with these documentation standards.