Six Ways to Use Drone Surveying for Asset Management of Solar Power Plants

In asset management of solar power plants, it is necessary to continuously monitor many elements not only the power-generating equipment itself but also the site, mounting racks, access paths, drainage, slopes, fences, and surrounding trees. The larger the site area becomes, the more difficult it is to inspect the entire facility to a consistent standard by ground patrols alone, and omissions in records and variability in judgments are more likely to occur.

Drone surveying is one method to broadly document the current condition of a solar power plant from the air and link it with positional information to make it easier to manage. Rather than mere aerial photography, continuously photographing the same area and organizing the data as orthophotos, point clouds, and elevation data makes it easier to compare changes in asset condition. Here, we explain six practical measures to leverage drone surveying for asset management of solar power plants.

Table of Contents

• Why Drone Surveying Is Useful for Asset Management of Solar Power Plants

• Measure 1 Standardize the criteria for assessing current conditions and link them to the asset register

• Tip 2: Manage equipment and the site on the same map

• Method 3 Use periodic surveys to monitor changes and inform repair decisions

• Tip 4 Save photo records together with location information

• Measure 5: Include peripheral assets such as drainage, slopes, and weeds in the scope of management

• Tip 6 Define data update rules to prepare for long-term operation

• Precautions when using drone surveying for asset management

• Summary

Why Drone Surveying Is Useful for Asset Management of Solar Power Plants

Asset management of a solar power plant is not sufficient if it only involves keeping an inventory of generation equipment. On site, the layout of panels and mounting structures, site boundaries, access roads, drainage routes, slopes, retention ponds, fences, gates, and surrounding vegetation are all interrelated. For example, poor drainage can lead to muddy accessways and damage to slopes, and the condition of weeds and nearby trees can affect inspection routes and shading.

If you try to manage this kind of information solely through on-site inspections, it tends to rely heavily on the responsible staff’s experience and memory. Even if photos are taken, it can be difficult to determine where they were taken. Even if drawings exist, if conditions have changed since completion they can become difficult to use for current asset management. Because a solar power plant is an outdoor asset and is continually affected by rain, wind, sediment, vegetation, nearby construction, and the like, the idea of regularly updating the current status is important.

Using drone surveying, you can record data that provides an aerial overview of the entire power plant. It becomes easy to check, like a single map, the arrangement of panel rows that are difficult to see from the ground, the continuity of walkways, the condition of the site edges, and the connections of slopes and drainage. Also, by periodically acquiring data under the same flight conditions and coverage, it becomes easier to compare differences with the previous survey.

The value in asset management is not simply obtaining clear images. It lies in making it easier to determine which assets are located where, where changes are occurring, and which actions should be prioritized. By linking drone survey results with asset registers, inspection records, repair histories, and patrol routes, information sharing is facilitated not only for field personnel but also for management departments, contractors, maintenance companies, and power plant owners.

Measure 1 Standardize the criteria for assessing current conditions and link them to the asset register

The first measure when using drone surveying for asset management of solar power plants is to align the standards for understanding current conditions. Images and survey data captured by drones have limited usefulness if simply stored as-is. To link them to the asset ledger, you must decide in advance which area, at what level of granularity, and which items they will correspond to.

In an asset register, panels, mounting structures, junction boxes, access roads, fences, gates, drainage facilities, slopes/embankments, and detention ponds may be managed. When these are managed only with drawings and lists, it can be difficult to understand their spatial relationships on site. By using orthomosaic images and terrain data obtained from drone surveying as a background and aligning the locations and extents of the facilities, it becomes easier to reconcile the information in the register with actual site conditions.

It is particularly important to standardize how names are assigned. On site, the same equipment may be managed under different names by different personnel. For example, if divisions such as panel rows, blocks, areas, aisles, and slopes remain ambiguous, inspection and repair records become difficult to trace later. Using drone survey results as a reference map and organizing section names and equipment numbers can reduce inconsistencies in the records.

Also, as-built drawings and design drawings do not necessarily match the current conditions. Adjustments during construction, additional work, repairs, changes to drainage routes, and changes in how access roads are used can result in differences between the information on the drawings and the actual site. In asset management, it is important to distinguish between assets as designed and the assets that actually exist on site and to verify them. By using current-condition data from drone surveying, it becomes easier to confirm where the equipment registered in the asset register actually is and what the surrounding conditions are.

If you try to manage everything in detail all at once, operations will become burdensome. It is more practical to start by organizing the overall site divisions of the power plant, the main equipment, and the locations that are likely to affect maintenance. The level of detail required depends on the purpose of asset management—whether it is to improve patrol/inspection efficiency, to create repair plans, or to prepare handover documentation. Before using drone surveying, decide which decisions the data will be used for, as this leads to asset management that is easier to use.

Tip 2 Manage equipment and site on the same map

In solar power plants, generation equipment and site conditions cannot be considered separately. While panels and racking are the generation equipment, the supporting ground, access paths, drainage, slopes, and fences are also important elements in asset management. If you record only the condition of the equipment without understanding its relationship to the surrounding environment, you may misidentify causes and countermeasures.

One approach in drone surveying is to manage equipment and the site on the same map. Using aerially acquired current data, you can comprehensively verify the layout of panel rows, the positions of access paths, the extents of slopes, drainage routes, fence lines, and the spread of vegetation. This makes it easier to identify risks that are difficult to detect when viewing equipment in isolation.

For example, if a pathway becomes muddy, looking at on-site photos alone can make it seem like a localized problem. However, by checking surrounding slopes and drainage routes with drone survey data, you may find that the terrain tends to collect rainwater from upstream. In another example, confirming from above where vegetation is growing near fences makes it easier to assess the management priority of site edges that are easily overlooked during patrols.

In asset management, not only the presence of equipment but also its ease of use and maintainability are important. Whether aisles that inspection vehicles can pass through are secured, whether there are access routes that allow easy access in an emergency, and whether the work ranges for mowing and repair tasks are clearly defined all affect the long-term operation of a power plant. If you visualize the entire site with drone surveying, you can confirm equipment management and the management of maintenance access routes in the same documentation.

When managing everything on the same map, it's also important not to cram in too much information. Overlaying all information on a single sheet can actually make it harder to read. Separate the information shown by purpose—such as power generation equipment, access routes, drainage, slopes, vegetation, and repair history—to make it more practical for operational use. Create a base map for asset management and enable switching to inspection, repair, or reporting views as needed; this also helps align understanding among stakeholders.

Measure 3: Use periodic surveys to monitor changes and inform repair decisions

In asset management for solar power plants, it is important not to stop after a single survey but to track changes. Outdoor facilities change condition over time. Erosion caused by rainfall, small slope failures, ruts in access roads, the spread of weeds, clogging of drainage channels, and changes around fences can all progress gradually. If changes can be detected at an early stage, it becomes easier to prioritize repairs.

By conducting drone surveys regularly, you can compare past data with current data. For example, by capturing the same area several times a year, it becomes easier to check seasonal changes in vegetation and terrain changes after the rainy season. If you conduct an ad hoc survey after heavy rain or strong winds, the data can be used as reference material to verify damage across a wide area. By combining regular surveys and ad hoc surveys, it becomes easier to distinguish normal changes from abnormal ones.

For making repair decisions, it is important not just to save images but to keep them in a format that is easy to compare. Recording the time of capture, the area captured, the weather, the surveying conditions, and the data processing methods makes it easier to determine whether differences from the previous survey are actual changes or simply appearances caused by different capture conditions. In particular, the appearance of shadows, the growth of vegetation, and the moisture level of the ground surface are easily affected by season and weather, so care is needed when making comparisons.

To make the most of periodic surveying in asset management, it is important not only to detect anomalies but also to link them to the intervention history. If repairs are carried out on a slope, recording the condition before the repair, immediately after the repair, and the subsequent condition makes it easier to verify the effectiveness of the measures. When cleaning a drainage channel, you can also compare the water flow and surrounding sediment accumulation before and after cleaning. This enables the information to be used as a basis for long-term maintenance decisions rather than one-off repairs.

Regular surveys are also useful for explaining matters to stakeholders. Rather than site personnel verbally saying "it's a little collapsed" or "the vegetation has increased," it is easier to share the situation by presenting past and current images side by side. When making decisions about budgets and work arrangements, having materials that concretely show the degree and extent of changes makes it easier to explain priorities. Drone surveys are effective not only for streamlining site inspections but also as records that support decision-making in asset management.

Tip 4: Save photo records together with location information

During inspections of solar power plants, a large number of photographs are taken. However, when only a lot of photos remain, it can be difficult to understand the location or context when reviewing them later. In large plants in particular, similar rows of panels and walkways continue for long distances, making it hard to accurately recall the exact place where a photo was taken. Photos used for asset management should be kept together with location information and equipment numbers.

Using drone surveying makes it easier to link overall aerial images with individual inspection photos. By linking and managing photo capture locations and inspection points on an orthomosaic of the entire power plant, you can intuitively see what is happening and where. Even personnel who have never been to the site can more easily understand the situation by looking at the map locations and photos.

In photographic records, it is important to clearly define the subject being photographed. For example, decide in advance the items you want to track in asset management, such as panel soiling, subsidence around mounting racks, damage to walkways, deformation of fences, blockage of drainage channels, and cracks in slopes. When photographing, record in the order of overall view, surrounding area, and close-ups; this makes it easier to understand spatial relationships and conditions later. By combining an overall view from drone surveys with ground photographs, you can manage both the broad area and the details.

It is also easier to make use of photos if the assessment results are recorded with them. Simply saving photos of abnormal areas does not indicate whether they have been addressed, are under observation, or require urgent repair. Recording the inspection date, inspector, assessment category, response deadline, and action history increases their value as an asset management ledger. If you organize photo records based on drone survey data, the flow of patrols, repairs, and reporting becomes connected.

What you should be careful about is not to judge solely based on how the photos look. Changes that stand out in images taken from above may actually be minor. Conversely, areas that look serious on the ground may turn out to be localized issues once viewed in relation to overall drainage and terrain. Combining drone surveys with ground verification and keeping records anchored to location data makes it easier to improve the accuracy of your assessments.

Measure 5: Include surrounding assets such as drainage, slopes, and weeds in the scope of management

When it comes to asset management of solar power plants, attention tends to focus on panels and electrical equipment, but for long-term operation the management of surrounding assets is also important. Drainage channels, slopes, access roads, fences, gates, mowing areas, and nearby trees have a significant impact on a plant's maintenance costs and safety. If these are left outside the scope of equipment management, they tend to be addressed only after problems have grown large.

Drone surveying is well suited to broadly assessing the condition of surrounding assets. For drainage channels, it makes it easier to identify low areas where water tends to collect, places where sediment is likely to accumulate, and flows that cross pathways. For slopes, it provides clues for locating areas with sparse vegetation, surface disturbances, and areas that may be at risk of collapse. For weeds and trees as well, confirming from above which areas are overgrown makes it easier to develop a weed control plan.

In asset management, it is important to position surrounding assets not as things to respond to only when anomalies occur, but as assets to be managed that support the functioning of the power plant. If drainage does not function, it can affect the condition of walkways and areas around foundations. If small changes on slopes are left unaddressed, the area requiring later repairs may expand. If weeds grow, they can hinder inspection work and provide hiding places for pests. By regularly recording surrounding assets, it becomes easier to detect early signs of problems.

When managing surrounding assets with drone surveying, you need a way to set priorities. Treating every weed and minor change as equally important makes management cumbersome. It becomes easier to put into practice if you focus first on locations with greater impact, such as areas close to power generation equipment, the origins or confluence points of drainage, the top and bottom of slopes, maintenance roads with high traffic, and fences near boundaries with external areas.

Also, it is important to take seasonal variations into account. Vegetation condition changes significantly with the seasons. The appearance of the ground differs between the dry season and the rainy season. When using the data as asset management records, you need to distinguish whether you are comparing data from the same season or assessing differences across different seasons. By conducting drone surveys regularly, you can identify trends in changes at each power plant, making it easier to develop management plans.

Tip 6: Set rules for updating data to prepare for long-term operation

A commonly overlooked aspect when using drone surveying for asset management is the data update rules. Survey data may be useful at the time it is acquired, but if it is not updated it will gradually diverge from the actual conditions. Solar power plants are assets operated over long periods, and personnel changes or maintenance system changes can occur. Therefore, it is important to organize data in a way that is clear to anyone and to establish a system that allows for continuous updates.

In the update rules, first decide the timing of surveys. Clarify whether to conduct a regular overall survey annually, during periods when vegetation or drainage changes are significant, or on an ad hoc basis after heavy rain or a disaster. It is not necessary to use the same frequency for all power plants. It is practical to vary the update frequency according to site conditions, such as locations where the terrain is stable, sites with many slopes, places where weeds grow quickly, or locations that have experienced drainage problems in the past.

Next, standardize data names and storage locations. In drone surveying, multiple files are generated, such as images, point clouds, orthophotos, drawings, and report materials. If file names are inconsistent, it takes time to find the desired data later. Assigning names according to a fixed rule—such as the power plant name, survey date, coverage area, data type, and version number—will make handovers less confusing.

Furthermore, it is important not to overwrite past data. In asset management, comparisons with past data are valuable. If you keep only the latest data and delete past records, you cannot track trends in change. Retaining data for each survey time and making it possible to compare them as needed makes it easier to verify correlations with repair histories and inspection results.

It is advisable to include the reviewers and approval workflow in the rules for updating data. After acquiring drone survey data, decide who will review the content, which information will be reflected in the asset ledger, and which anomalies will be designated for follow-up. Whether decisions are made solely by on-site personnel or shared with management departments and maintenance contractors will change the required format of the documentation. Establishing the operational workflow from the outset prevents survey data from merely being stored without further action.

In long-term operations, it is important that data remain understandable even if the people using them change. By recording imaging conditions, survey area, how coordinates and elevations are handled, processing methods, items checked, and decision criteria, the next person responsible can make comparisons under the same assumptions. Drone surveying for asset management should be designed not as a one-off convenient survey but as a system for building up a power plant’s history.

Precautions when using drone surveying for asset management

Drone surveying is useful for asset management of solar power plants, but it is not万能. There is information visible from above and information that cannot be determined without on-the-ground confirmation. For example, equipment internals, electrical abnormalities, minor loosening of fasteners, and subsurface conditions cannot be assessed by drone surveying alone. In asset management, it is important to use drone surveying as a means of gaining an overall understanding and to follow up with ground inspections or detailed investigations as needed.

Also, care is needed in how surveying accuracy is handled. The required level of accuracy varies depending on whether the purpose of asset management is to grasp the overall current situation, manage equipment locations, or compare terrain changes. Demanding finer accuracy than necessary for the purpose makes the work and processing heavier. On the other hand, when using the data for repair decisions or drawing updates, it is necessary to carefully check positional discrepancies and how elevation is handled. Aligning the purpose with the required accuracy leads to drone surveying that is practical and easy to use in the field.

Flight plans also require careful consideration. At solar power plants, define a safe flight area after checking panel surface reflections, overhead lines, surrounding trees, terrain variations, wind effects, and the nearby environment. Even within the premises, you must consider the safety of third parties, nearby facilities, and workers’ movement routes. Depending on the flight location and method, you also need to confirm applicable laws such as the Aviation Act, rules of local governments and facility managers, and any required procedures. Because surveys for asset management may be conducted regularly, standardizing the on-site inspection procedures each time makes it easier to balance safety and efficiency.

Care is also required when interpreting the data. While images captured by drones are easy to understand, impressions can be affected by shadows, reflections, the way grass is lying, and the moisture of the ground surface. Rather than judging an anomaly from images alone, it is important to make determinations by combining past data, ground-level photographs, inspection records, and observations from on-site personnel. In particular, information that affects a power plant’s asset value or decisions about repairs should be verified by multiple lines of evidence before being consolidated.

In materials shared with stakeholders, using language that isn’t overly technical is important. When explaining to administrative departments or owners, it’s more important to convey where changes have occurred and what actions are required than to focus on the detailed specifications of point clouds or survey data. Rather than handing over drone survey results as-is, organizing them into a form that can be used for asset management decisions increases their practical value.

Summary

Using drone surveying for asset management of solar power plants makes it easier to get an aerial overview of large sites and diverse equipment. Because you can comprehensively capture not only panels and mounting racks but also access paths, drainage, slopes, fences, weeds, and surrounding trees, it becomes easier to organize site conditions as asset management information. In particular, by linking current-condition data with the asset register and inspection records, you can move toward management that does not rely on the memory of individual staff.

The key point for effective use is to clarify the purpose. Depending on whether it will be used for current condition assessment, patrol/inspection efficiency, repair planning, post-disaster checks, handover documentation, or other purposes, the required data and update frequency will vary. Managing equipment and the site on the same map, tracking changes through regular surveys, and keeping photo records paired with location information will make it easier to continuously compare the power plant’s condition.

At the same time, it is important not to base all judgments solely on drone surveys but to combine them with ground inspections and detailed checks. By linking the aerial overview information with the detailed information verified on site, you can improve the accuracy and efficiency of asset management. With long-term operations in mind, it is important to decide in advance the data names, storage locations, update frequency, verifiers, and decision criteria, and to keep records that anyone can use.

Asset management of a solar power plant is not just about storing as-built documents; it is an effort to continuously monitor changes during operation and translate them into necessary responses. By effectively incorporating drone surveying, site visualization, record standardization, and information sharing among stakeholders can be advanced, making it easier to make decisions that protect asset value. If you want to improve understanding of the plant’s current condition and streamline asset management, start by clarifying the objectives, required accuracy, flight conditions, and data management rules, and by establishing an operational system that can be coordinated with ground inspections—this makes it easier to implement in practice.