10 Most Common PV System Anomalies Detected by Drones (Part B)

10 Most Common PV System Anomalies Detected by Drones (Part B)

 

Solar companies involved in the design, build, management, and/or maintenance of PV systems are increasingly moving to UAS (drones) to replace field work that take large amounts of time and money. Field walks, IV curve tests, voltage checks, and handheld thermal scans of modules are just a few examples of tasks being replaced with drones by O&M teams around the world. Drones set up with both thermal (IR) and high-resolution (RGB) imaging cameras allow for common mislabeled anomalies (ie. soiling) to be properly identified and not mistaken for module hot spots.

 

In this “Part B” post we are going to cover additional PV system anomalies that can be identified during an aerial solar site inspection performed by a drone. If you missed out on reading “Part A” of  10 Most Common PV System Anomalies Detected by Drones click here.

 

Before we get started, it’s important to make sure you’re familiar with the general workings of PV systems. This is a must when it comes to inspecting solar sites effectively with a drone. Here’s a quick breakdown:

Solar sites → A solar site can have hundreds of rows→ Single or multiple strings are within a row→ Strings are made up of modules→ Modules are made up of several photovoltaic cells (Polycrystalline, amorphous, TPV, multi-junction)

 

1. Combiner off-nominal (warm) or offline

Site level issues such as off-nominal or offline combiners pose a serious threat to the efficiency of a PV system. An anomaly of this scale requires immediate maintenance and is always considered an issue of the highest priority. Combiner anomalies are often mistaken for string level issues. However, their identifying quality is when entire rows clustered together present as warm abnormal geometry in your thermal imagery. To determine it is a combiner issue always reference the as-built. Below is an example of a off-nominal or offline combiner.

 

2. Inverter off-nominal (warm) or offline

Inverter anomalies are also a high priority issue that can drastically affect the power production of a solar site. Similar to combiner level issues, inverters present themselves in thermal imagery as multiple rows in a unique geometry that appear warm or offline. Always reference the as-built drawing and site wiring to confirm that it is an inverter issue. Examples of inverter anomalies include:

 

 

3. Discrepancies from as-built – missing modules, incorrect build

Another common anomaly often identified with a drone inspection is discrepancy from the as-built documents, shown through missing modules, or incorrect builds. These differences are often missed from ground level, but easy to identify within an aerial inspection dataset. Before you perform your PV system inspection make sure you have documents such as site information, layout, and as-built diagrams for reference. When entire modules/parts of PV strings are missing, overall DC power production is dramatically affected.

 

4. Weather damage – hail damage, flooding, windstorm, tornado

With little to no protection PV systems are regularly exposed to the elements and extreme weather conditions. Tornadoes, lightning, high-speed winds, hail, and flooding can all cause tremendous damage to solar sites. Large hail can cause cause shattering, while strong winds can uproot and displace modules from their original position. Although it may not be easily identifiable with system monitoring, weather damage can greatly impact PV health/performance and requires immediate attention.

 

5. Delamination and Other Types of Potential Module Anomalies

Delamination and other suspected module defects are commonly found on both new and old sites. Delamination and other module defects can be spotted in either thermal (radiometric) or RGB imagery, depending on the anomaly, and can appear in several forms. They most commonly look similar to:

 

 

 

Are you interested in learning more about UAS, drone inspections of solar assets, and having your data converted into PV analytics and system reports? If so, please contact us here and our team will be in touch.

Opportunities for Drone Inspections in Solar: PV System Commissioning

Opportunities for Drone Inspections in Solar: PV System Commissioning

The renewable energy sector has seen a tremendous amount of growth over the last few years, and PV (solar) has shifted to the forefront of new clean energy development. In fact according to SEIA, Solar has ranked first or second in new electric capacity additions in each of the last 5 years.”  As of 2017, nearly 56 GW of total solar capacity has now been installed in the US. Solar sites are being built at a never before seen pace and scale on rooftops, deserts, northern climates that see snow and below 0ºF temperatures, and other varying locations around the world where solar is a new energy source. 

 

With the massive growth of solar projects in development and being completed around the world, there are several opportunities for solar companies and asset owners to replace traditional, labor-intensive tasks with drones. Drones can provide value across the cradle-to-grave lifespan of a solar asset, from initial planning/design to ongoing annual maintenance. Using drones within the commissioning of a new PV system is a quick and effective method to assess the quality and operational health of a new plant. In this post, we will cover the commissioning process of a solar project, the benefits of using drones during this stage, and how drones specifically are helping teams reduce time in the field and labor costs associated with PV system commissioning.

 

What is commissioning?

Commissioning is the process which ensures that the PV asset owner’s goals and needs have been met and maintained. This can encompass anything from construction deadlines to safety requirements. These elements are assessed through inspections which cover all aspects of the site from installation to closeout. According to SolarPro the following are to be included in the commissioning process:

  • Verify that the installation is complete.
  • Verify that the installation is safe.
  • Verify that the installation is aesthetically acceptable.
  • Verify that all components of the installation are robust and permanent.
  • Document as-built conditions.
  • Verify system performance.
  • Verify proper system operation.
  • Establish performance benchmarks.
  • Complete any required acceptance documentation.
  • Train the system owner on basic system operation.

 

Benefits of Using Drone Inspections for Solar Commissioning

Because the commissioning process for PV systems is comprised of several technical inspections the use of drones has allowed field technicians, asset owners, and commissioning teams to cut time, costs, and manpower involved in PV site commissioning.

Using drones to replace the field walks, visual inspections and handheld thermal inspections saves large amounts of time and enables teams to spend labor hours on other high-skilled tasks. Drone inspections also deliver a more granular level of data to the end user and a more complete picture of the site in both thermal and high-resolution imagery. Top-down and elevated imagery captured with a drone allows for all anomalies to be identified clearly and in a consistent manner.

 

Commissioning for Warranty

The commissioning process also plays a key part in issuing warranty claims. Many contractors, vendors, and service providers are involved in the development and construction of a solar site and many times warranties are provided to support the work done.

Engineering firms, EPCs, and drone inspection service providers are all beginning to use drones at this stage of a project. Every party involved in this stage of a project can leverage drone data and solar software like Raptor Solar to quickly and easily confirm work has been done as planned.

 

Documentation of Site Commissioning with Raptor Maps

One of the most important factors of commissioning is proper documentation. When performing inspections in a site portfolio manner it is important to have understandable and cohesive reporting and documentation for all aspects of the commissioning process. 

Using analytic and reporting software like Raptor Solar allows companies to turn their drone imagery/video into comprehensive analytics and baseline reports on the overall DC health and condition of a site. A report that provides data and supported imagery on every module of a site will enable asset owners and managers to establish a baseline dataset of the site and compare future inspections against this baseline and track the development of the site over time.

 

Conclusion

With the solar industry growing at an unprecedented rate, new ways to implement drones for asset monitoring and inspection are being uncovered. The benefits of using drones for commissioning inspections are endless as they are providing more detailed inspections for warranty claims, installation checks, and verifying power performance.

Are you using or looking to use drones for solar commissioning? If so, please contact us here and our team will be in touch.

 

 

Are you interested in learning more about UAS, drone inspections of solar assets, and having your drone data converted into analytics and PV system health reports? If so, we highly recommend reviewing our recent webinar with FLIR, Inspecting Solar Farms with Thermal Imaging Drones, here.

When To Perform Your Drone PV System Inspection: 3 Key Factors to Keep in Mind

When To Perform Your Drone PV System Inspection: 3 Key Factors to Keep in Mind

Collecting aerial solar inspection data using your drone can be tricky. With numerous factors impacting the outcome of your data, it is essential to plan drone flights. People often ask Raptor Maps what’s the best way to collect clear and report-worthy data?

The answer is to know the WHO, WHAT, WHEN, and WHERE of your project. WHO are you collecting data for/ WHO is collecting your data? WHAT are you looking for (types and/or level of detail of anomalies on site)? WHEN are you collecting your data? WHERE is the inspection occurring (geographic location of the site)? The WHY of aerial drone solar inspections is simple: using drone inspections in the solar industry optimizes your workflow, increases productivity, reduces labor costs, and improves safety.

One of the most important, yet overlooked is the WHEN aspect of data collection. Factors including season, weather, and the time of day the drone inspection occurs can dramatically impact thermal data. Whether a solar asset owner, O&M company, or service provider, the quality of drone solar inspection data matters.

Keep reading as we break down the following WHEN factors:

  • Time of Year
  • Weather
  • Time of Day

 

1. Best Season to Perform Aerial Solar Inspections

Inspections of solar assets are best performed in clear, sunny weather months. Although it depends on the geographical location of the solar site, drone inspections during the spring, summer, and early fall tend to produce the best data because of their tendency for high irradiance. In fact, irradiance on a clear summer day can be up to 20 times higher than on a cloudy winter day. The sun, warmer climate, and higher irradiance associated with these seasons allow for site anomalies such as hot spots and string/module failures to be more visible in thermal imagery. The long days during summer months also allow for a larger window to collect high-quality data. Extended hours of sunlight will provide you with greater opportunity to collect proper data and also allows you time to re-fly if needed.

 

2. Fly in Perfect Weather Conditions  

Flying when the sun is shining is the most important weather factor to take into account. High irradiance produces clear data and makes defects evident when performing post-processing/data analysis. According to the National Renewable Energy Laboratory, the recommended minimum irradiance to perform thermal inspections is 600 W/m2. This describes the amount of solar (radiant) power per surface unit area necessary to perform thermal inspections. Pay extra attention when flying at high latitudes in the winter during low-irradiance conditions since. Low wind conditions are also a must in order to keep your drone on the mission course, preserve its battery life, and capture images free of motion blur and glare.

 

3. Midday Flights Lead to Quality Data

High irradiance, as stated before, is a key factor for collecting quality data. With the sun at its highest, and irradiance at its strongest, midday flights tend to produce the highest quality data. However, stay away from performing inspections close to, or around noon in order to avoid glare in your data set. Plan to start data collection mid-morning so you can collect, review, and re-fly (if needed) during high irradiance hours.  

 

In conclusion, WHEN you fly your solar assets can make or break your thermal data. Look to collect data in the summer months where the sun is strong, the wind is low, and there is an ample amount of time to perform your drone solar inspection. Learn more about collecting thermal data by watching our webinar with FLIR Systems here.

 

 

Are you interested in learning more about UAS, drone inspections of solar assets, and having your data converted PV analytics and system reports? If so, please contact us here and our team will be in touch.

10 Most Common PV System Anomalies Detected by Drones (Part A)

10 Most Common PV System Anomalies Detected by Drones (Part A)

Solar companies involved in the design, build, management, and/or maintenance of PV systems are increasingly adopting UAS (drones) to replace field work that takes large amounts of time and money. Field walks, IV curve tests, voltage checks, and handheld thermal scans of modules are just a few examples of tasks being replaced with drones by Asset Management and O&M teams around the world. Drones set up with both thermal (IR) and high-resolution (RGB) imaging cameras allow for commonly mislabeled anomalies, ie. soiling, to be properly identified and not mistaken for module hot spots.

In this post, we are going to cover the range of PV system anomalies that can be identified during an aerial solar farm inspection performed by a drone. Before we get started, it’s important to make sure you’re familiar with the general workings of PV systems and how they operate. This is a must when it comes to inspecting solar farms effectively with a drone. Here’s a quick breakdown:

Solar farm → A solar farm can have hundreds of rows→ Single or multiple strings are within a row→ Strings are made up of modulesModules are made up of several photovoltaic cells (Polycrystalline, amorphous, TPV, multi-junction)

 

1. Module Level Issues  

Possibly the most common anomaly discovered during aerial drone inspections are module level anomalies. Several types of anomalies can appear within the frame of a PV module, including cell hot spots, multi-cell hot spots, and activated bypass diodes. Although not as severe as string issues, module anomalies, especially when in abundance can drastically reduce the efficiency of a PV system, and when left unattended over long periods of time, might develop into a more serious issue.

2. Shadowing

Shadowing of PV modules, strings, and rows is a commonly identified anomaly from a drone inspection. Shadowing can be caused by vegetation, surrounding structures, and even adjacent solar rows. Although most occurrences of shadowing do not require PV technician attention, shadowing due to vegetation can lead to larger problems if not addressed earlier.

Identifying shadowing in both the IR (thermal) and high-resolution drone inspection imagery can help Asset Management and O&M teams more effectively spend budgeted maintenance costs on vegetation management. We recently helped a solar plant manager in south-central Asia use his internal drone program and regular drone inspections to make more informed decisions on when to dispatch his vegetation management contractor.

3. Shattering & Soiling

Some issues are detectable through the RGB imagery taken during data collection. These anomalies are mostly associated with the physical attributes of the farm. Shattering (cracked glass) of panels due to module installation, maintenance, racking shifts, or severe weather is an anomaly that can be easily detected with RGB imagery.

Soiling from dust, bird droppings, and other debris can also heavily affect the efficiency of PV modules.

4. String Level Issues

String issues are the most severe (and easily detectable) anomalies when flying and analyzing your inspection data. Strings (composed of modules) can be warm, offline, have reversed polarity, or completely fail which causes large energy losses within the PV system.

 

5. Tilt Tracker Alignment and Racking Issues

If the solar farm is built on tilt trackers rows and panels can get stuck in a certain orientation reducing their efficiency. Not all solar sites are built on tilt trackers but, those that need to be thoroughly assessed for angle discrepancies caused by installation, or maintenance errors.

Are you interested in learning more about UAS, drone inspections of solar assets, and having your data converted PV analytics and system reports? If so, please contact us here and our team will be in touch.

Raptor Maps Awarded MassCEC Grant for Real-Time Identification and Classification of PV Faults

Raptor Maps Awarded MassCEC Grant for Real-Time Identification and Classification of PV Faults

Raptor Maps is excited to announce we were recently selected as a finalist for the Massachusetts Clean Energy Center’s (MassCEC) latest round of InnovateMass awardees. We will be collaborating with Enel Green Power (EGP) to develop brand new capabilities combining machine learning with state-of-the-art drones and IR cameras for the inspection of PV systems.

EGP’s North American drone team, which specializes in aerial inspections and management of their PV assets, will be working with Raptor Maps to,

optimize the software for real-time identification and classification of faults onboard the drone, helping make maintenance of solar farms cheaper and more effective.”

The Raptor Maps solar software solution, Raptor Solar™, will be incorporated into field operations to automate their drone data analysis and report generation. The goal is to advance EGP’s drone operations by integrating their hardware with Raptor Maps’ software for real-time identification and classification of solar faults using machine learning and Artificial Intelligence (AI). Raptor Solar is revolutionizing the solar industry by enabling asset owners/manager (such as Enel Green Power) and O&M teams to have the most advanced system analytics on the DC health of their solar assets.

 

About Enel Green Power, Enel Green Power is dedicated to the development and management of energy production from renewable sources worldwide. They specialize in solar, wind, hydroelectric, geothermal, and biomass energy with over 1,200 active plants in 30 countries. Enel Green Power’s goal is to innovate in the fields of research and production of electrical energy from renewable sources in order to improve the company as well as the communities in which they work. Their sustainability model is changing the way we produce energy around the world.

About Massachusetts Clean Energy Center (MassCEC), MassCEC is a state economic development agency working to accelerate the growth of clean energy, spur job creation, deliver statewide environmental benefits, and to secure long-term economic growth for the people of Massachusetts. MassCEC is dedicated to increasing the adoption of clean energy. They are active supporters to those making a difference in the sustainable energy sector and deliver financial, environmental, and economic development benefits to energy users and utility customers across the state.

 

Are you interested in learning more about UAS, drone inspections of solar assets, and having your data converted PV analytics and system reports? If so, please contact us here and our team will be in touch.