How to: Conduct an Aerial Solar Panel Inspection

What superpower would you choose to make your job easier? Would you favor x-ray vision, heat detection or harnessing the power of flight? Aerial drones or Unmanned Aerial Vehicles (UAV) combine These capabilities to carry out aerial solar inspections, a rigorous task for field technicians, to capture data and send insights to the maintenance team.

What is an Aerial Solar Inspection? 

Drones are here to save the day. Benefits include:

  • Aerial inspections enable you to document and diagnose panel degradation, scan inverters and data capture vegetation management. Traditional inspections are conducted and are limited to a sample of the site while drones oversee the entire solar project.
  • You can check modules output and make a warranty claim if equipment is not generating at optimal levels.
  • Drones can survey an entire solar farm to identify faults in a fraction of the time and expense.

Aerospec Technologies save their clients an average of $1,916 per MW per inspection. Clients with larger solar farms can save thousands of dollars annually. 

Is It a Bird? Is It a Plane?

Drones are equipped to capture quality asset data that humans cannot reach with traditional handheld readers. Drone inspections utilize aerial thermal imaging to locate and diagnose faults where electricity production has visibly dropped, allowing owners to act on operational inefficiencies and optimize power generation

Anomalies include cell and string defects, defective diodes, bird or snail debris, inverter problems and short circuits. The following illustrates how these appear under “infrared vision”.

Aerial Solar Inspection
Source:Drone Life NJ

Equipment You Need for an Aerial Solar Panel Inspection 

With the right equipment, inspectors can conduct aerial solar inspections more accurately and efficiently. Let’s face it, time is money, so the more effective an inspection, the more owners can see a return on investment (ROI).

We recommend the following gadgets in your aerial inspection toolbelt

  • Drone and remote – Not all drones are created equal. Make sure the drone model is suitable for aerial inspections by checking camera compatibility, long battery life and a built-in flight automation feature.
  • Infrared camera – An infrared camera can detect faults in heat patterns naked to the human eye. Resolution should be no less than 640×512 and sensor focal length between 13mm-19mm. Dual RGB and thermal images are more advantageous for capturing loss of solar power generation.
  • Computer or tablet – A tablet has portable advantages in the field, but a compatible device to access drone software and review asset data is a necessity. 
  • Solar Irradiance Meter – Measures the amount of solar power panels collected to maintain consistent adequate levels (minimum of 600 watts per square meter).
  • Cleaning and repair kit – Retain optimal footage quality and protect your camera from damage in dry, dusty or wet weather with an adequate cleaning kit.
  • Computerized Maintenance Management Software – What happens to all that footage? A CMMS like 60Hertz centralizes all maintenance data in a time series database allowing your teams to action urgent maintenance alerts and archive maintenance logs

Our offline capability means jobs can be updated on site in low to no network connection.

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60Hertz’s CMMS is the on-the-go, offline-friendly data management software for maintenance teams across the world.

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Maintenance is Changing. Are You Keeping Up?

How to Conduct an Aerial Solar PV Inspection

With the information above, now you’ll need to know how to conduct an aerial solar PV inspection.

Plot a Course

Compared to traditional hand-held devices that are limited to ground-level data collection, drones are a more economical, accurate and safe method for undertaking solar panel inspection  that offer a wider view of potential equipment failures. 

Daniel McColl establishes that “aerial inspections can be done in a matter of hours and require far less manpower to conduct. Typical aerial inspection drones can cover up to 10 MW per hour, whereas manual inspections would be lucky to cover 1 MW in 10 hours of work.” 

With that being said, inspectors must plan the most efficient flight route to elevate ROI and capture quality data. Things to consider:

  • Flight start times, speed and duration for optimal efficiency and imaging quality
  • Plan for poor weather conditions (hail, cloud, acid rain, hurricanes etc)
  • Data collection software or a CMMS to automate and action maintenance work orders
  • Battery economy and charge duration
  • Drone maintenance expenses
  • Route planning software to automate the flight path and maintain image consistency (see example below)
Aerial Solar Panel Inspection
Source: Flight planning requires several inputs to achieve complete coverage

Flight Altitude and Angles

An efficient aerial inspection is expendable if you don’t collect quality data. Plotting the most economical course is critical to capturing quality asset data. Depending on the size of the solar farm, the angle may need to be adjusted to accommodate the moving panels during the flight.

Aerial Solar PV Inspection

Take Off With the Right Baseline Data

The best time to “get off the ground” with your inspection program is at handover. According to TUV Rheinland’s study, 80% of module defects occur prior to operations. This gives you the chance to establish baseline data with which to compare to later inspections. You should also check for correct installation and that everything is operating as it should.

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How Often Should Solar Panels Be Inspected? 

Regular health checks are necessary to spot faults before they turn into more expensive problems, maintain asset lifespan and achieve optimal electricity production. 

Drone Life recommends “to stay on top of your solar plant’s maintenance, you should inspect your solar plant 1-2 times per year.” However, how often you want to carry out these health checks depends on many variables such as:

  • Weather conditions such as hail will cause more damage to panels, whereas windy environments can blow dirt and debris
  • Buildings or vegetation cause shade on panels, which needs to be monitored and maintained for optimal sunlight exposure. 
  • Curious animals can chew wiring and migrating birds may decorate your panels on their flight path, requiring more regular cleaning.

It may take some time and data analysis to fully optimize your aerial solar inspection procedure but with each fight comes data learnings that better inform your maintenance decisions.

Raptor Maps – Aerial Inspection Software

As solar technology becomes more mature and widespread, you should know that the rate of anomalies is increasing.  Raptor Maps’ most recent Global Solar Inspection Report found a notable increase in power affected by anomalies, rising to 2.63% in 2021 from 1.85% in 2020, a more than 100 MW energy production impact.

Our Raptor Solar software covers the entire solar lifecycle, offers unlimited inspection reports and provides actionable information about anomalies. We associate each anomaly and the power affected with a dollar amount so that teams can make informed decisions about restoring lost production. 

You’ll be able to boost profit by quickly identifying anomalies and quantifying their cost.

Commissioning inspections lessen the burden of a project’s risk for the asset owner and their O&M team by ensuring a high baseline and the condition of assets. In commissioning, the aerial inspection can become a standard item to check off for the EPC. This is critical because it allows teams to fix any OEM issues in the warranty window.  

We’ve seen many clients use this technology at 3-6 month intervals to closely monitor the site while in this window of time. Thereafter, during operations frequency of inspection varies from once a year to several times a year. Inspections are also often done during times of due diligence related to mergers and acquisitions.

Raptor Maps strictly follows IEC TS 62446-3:2017 standards for aerial thermography and we offer specifications that can be added to various contracts.  The specifications are free and can be downloaded on our website.

Effectively manage your aerial solar inspections with the right CMMS. Contact us today, and learn how 60Hertz can help.

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