Drones for Post Commissioning Inspection
Updated: Nov 27, 2019
It takes several months for complete installation of large utility scale solar PV plant. With extreme time pressure to complete diverse activities and tasks being physically intensive, damages in PV modules due to mis-handling and string disconnections due to improper workmanship or connector issues are a common sight post commissioning.
With plants ranging from 100 MW – 300 MW being common across a few geographies like India, Spain, Australia, USA and upto 1GW in Middle east, post commissioning quality check is laborious and time consuming with tens of engineers/ technicians on a marathon of inspection checks taking about 3-4 months for plant stabilization. One of the ways of resolving string isolations is through SCADA monitoring systems, but benchmarking to identify string isolations and establishing reliable communication at this stage is quite a challenge. Furthermore, manufacturing defects such as bypass diode issues, junction box overheating, solder joint issues etc. can neither be inspected manually nor be diagnosed through SCADA.
These challenges create major hurdles to project (EPC) teams to have a smooth Performance Guarantee (PG) test experience, deliver quality work to the developers and efficient handover to the O&M and asset management teams. Thus, all the stakeholders involved find it difficult to ensure maximum energy generation and quality handover.
With an objective to ensure rapid generation improvement within few days of commissioning along with helping streamline activities like grass-cutting, cleaning and module inspection, AirProbe introduced aerial thermal inspection technology in post commissioning stages of PV assets. The team worked closely with the EPC associates responsible for installation of a 300MWp PV site in North India. After comprehensive planning and realizing the potential of drones at this stage, the EPC team chose to utilize drones to detect isolated strings over clamp meters and thus leading to rapid generation ramp-up.
With our streamlined workflow requiring only 20% sidelap vs 65-80% sidelap for conventional mapping, the EPC team could capture the complete data within 5 days using a single drone. Furthermore, by using our proprietary Artificial Intelligence (AI) based data analysis algorithms, the inspection results were reported every alternate day to the site engineers which is extremely necessary at this phase due to dynamically changing ground conditions. String isolations, short circuited connections, damaged modules and bypass diode activated modules were the major findings from the inspection.
With easy identification of module level fault locations reported over the site layout, the EPC engineers could ramp up the energy generation by about 3.2% just by resolving isolated and short-circuited faults within first week after commissioning. The bypass diode activated and multi cell mismatch hotspot affected modules were reported to the manufacturer for warranty claims. Damaged modules were claimed under the insurance cover.
Moreover, precise geographical locations of high vegetation growth areas and heavily soiled modules were reported in inspection results that helped the EPC teams streamline their vegetation cutting and module cleaning activities more efficiently. It also provided a complete installation quality index of different subcontractors to the EPC and O&M teams.
With the success of this project and spreading the value of this technology to more than 4.5 GW of PV asset inspection worldwide, AirProbe aims at building a comprehensive global digital platform enabling the stakeholders of solar PV domain to inspect, analyze and manage their assets. Reach out to us to get the full copy of the case study with ROI analysis for this phase and together let’s make Solar assets across the world operationally efficient and reliable!