3D with Point Cloud Scanning! Secrets to Improving Efficiency at Solar Construction Sites

Background of 3D Adoption at Solar Construction Sites

With rising demand for renewable energy, the construction of solar power plants and large-scale solar farms is rapidly increasing. These sites require the installation of tens of thousands of panels across vast areas, involving large-scale earthworks and installation operations. However, relying on traditional 2D drawings and manual labor makes it time-consuming to check extensive terrain and progress, increasing the risk of gaps between design and actual conditions. Even experienced construction managers cannot easily translate design-only information on drawings into a completed site image. In addition, the construction industry faces labor shortages and an aging workforce, so moving away from analogue management to improve efficiency with limited personnel has become urgent.

Digital transformation (DX) of the site is attracting attention as a solution to these challenges. The Ministry of Land, Infrastructure, Transport and Tourism's i-Construction policy recommends the use of ICT and 3D data, reflecting the demand for site work that adopts the latest technologies. Visualizing the entire site in 3D and being able to understand alignment with design data in real time can reduce the workload of traditional surveying and reporting, and decrease rework caused by measurement errors or design mistakes. 3D conversion using point cloud scanning is expected to be a key component of this DX.

What Is a Point Cloud? Acquisition Methods and Technological Advances

A point cloud is a collection of large amounts of three-dimensional coordinate data acquired by methods such as laser ranging or photogrammetry. This creates point cloud data that can reproduce the overall shape of a site, including buildings and terrain, with high accuracy. Acquisition methods include terrestrial laser scanners (TLS), aerial photogrammetry using drones, and, more recently, easy scans using LiDAR sensors or stereo cameras built into smartphones.

Thanks to advances in technology, obtaining point clouds has become more accessible than ever. What once required expensive specialized equipment can now be achieved more easily: drones, smartphone cameras, and even 360-degree cameras can capture images that are processed in the cloud to generate 3D models. In particular, the latest smartphones, when combined with high-precision surveying GPS (RTK), allow field staff to acquire point cloud data with centimeter-level accuracy without waiting for specialized technicians. These technological advances are accelerating DX in solar construction sites.

Comparing Methods: Drones, Smartphones, LiDAR, and More

There are various methods for acquiring point cloud data, each with its own characteristics.

• Drones (UAVs): Drone aerial photography offers a bird’s-eye view and is well suited to surveying wide areas of several square kilometers or more. Photogrammetry, which processes many captured photos in the cloud to generate point clouds, is effective for understanding terrain and progress at vast mega-solar sites. However, drones depend on flight permissions and weather conditions and are weak in blind spots such as under trees or inside tunnels.

• Smartphones: Modern smartphones are equipped with LiDAR sensors and AR cameras, enabling handheld, simple 3D scanning. If a smartphone is connected to a compact RTK receiver, centimeter-level surveying can be achieved. Smartphones are easy to use and low cost to introduce, allowing site personnel to start using them immediately. However, the surveying range depends on line of sight and sensor performance, so covering a large site quickly is more effective when combined with other methods such as drones.

• Handheld LiDAR scanners: Dedicated handheld LiDAR devices can capture highly accurate, dense point clouds. They are suitable for complex structures or inside tunnels where drones struggle. However, their weight and cost can make it difficult to have multiple units available for everyday use.

• 360-degree cameras: Some 360-degree cameras also support point cloud generation and offer the advantage of capturing the surroundings at once, particularly indoors or in complex sites. However, resolution and accuracy vary by model, so it’s necessary to verify in advance whether they meet the quality required for construction management.

As shown, drones, smartphones, and LiDAR each have strengths and weaknesses. In practice, it is common to combine suitable tools based on site size, required accuracy, cost, and worker skill levels.

Verifying Consistency by Overlaying Design Data and Point Clouds

By overlaying point cloud data captured on site with 3D models or 2D drawings from design, you can verify construction progress and as-built consistency. For example, comparing the panel layout and mounting height in the design data with the scanned terrain and installation conditions makes it easy to see where positional deviations occur.

Specifically, import point cloud data into visualization software and align it to 2D/3D design data as a reference. If geographic coordinates are unified via RTK positioning, this task becomes straightforward. After alignment, features that color-code differences between plan and actual conditions can immediately highlight areas that do not meet the designed heights or show pile position deviations. Comparing and checking in 3D this way eliminates the need to reconcile survey results on paper as was traditionally done.

If the design data is created in 3D CAD (BIM/CIM), you can overlay and manipulate the design model and on-site point cloud on screen for comprehensive checks, including hidden areas. Before crane delivery of panels or mounting frame installation, overlaying the current terrain with the predicted completion model via AR helps intuitively decide whether to add or remove soil to reach required heights, preventing post-construction discrepancies.

Streamlining Earthwork Volume Calculation, Pile Inspection, and Site Formation Progress

Using point cloud data improves efficiency in managing earthworks progress and quality inspections. For earthwork volume calculation, comparing the point cloud of the existing terrain with the design terrain automatically computes cut-and-fill volumes. What used to be manual volume calculations for each work section can be automated, allowing rapid assessment of results on site. This improves planning for heavy machinery deployment and schedule adjustments, making it easier to predict surplus or shortage of soil.

For pile driving of mounting frames and foundations, comparing pile positions derived from point clouds with design data lets you confirm installation positions and height errors on the spot. For example, marking pile driving locations with a smartphone linked to RTK or scanning the installed piles with a smartphone camera afterward to compare installation status speeds up inspections. If pile misalignment or insufficient depth is detected, it can be identified during construction to reduce rework.

Furthermore, using point clouds makes it easy to monitor the overall progress of site formation. Periodic scans of the current terrain with drones or terrestrial scanners compared to design data visualize how much work has progressed and whether it is being completed as planned. Changes in 3D shapes that were hard to grasp from site photos or traditional 2D drawings can be captured comprehensively with point clouds.

Connecting Site, Office, and Design Teams via the Cloud

Upload captured point cloud data, photos, and surveying information to the cloud and share them among the site, office, and design personnel to streamline project-wide information coordination. For example, photos and point cloud data captured and recorded on a smartphone with location information are automatically saved to the cloud, enabling remote designers and supervisors in the office to check them in real time.

This greatly reduces the time spent preparing reports after returning to the office and the hassle of exchanging documents by email. The design team can always be aware of the latest site information, allowing timely design changes and additional instructions. Managing progress data and as-built records in the cloud also makes it easy to reference past data, compare records, and centralize inspection documentation. Sharing information across multiple sites and different contractors becomes simple, enabling everyone to work from the same 3D data.

Realizing Site DX with LRTK: Point Cloud Scanning, RTK Positioning, AR Display, and Cloud Integration

To achieve the DX described above, a workflow using the smartphone app “LRTK” is effective. LRTK includes features that allow surveying and point cloud scanning on site with just a smartphone. The 3D point cloud data obtained by scanning the current terrain is automatically uploaded to the cloud and can be viewed and shared instantly in a browser. If you upload design data to the same cloud, overlaying point clouds with design models to check for differences is simple.

LRTK also supports RTK positioning, enabling centimeter-level position measurement with a compact GNSS receiver connected to a smartphone. This allows pile location and height surveying to be completed with only a smartphone, removing the need to carry heavy surveying equipment. In addition, using AR features, you can overlay the design model on the smartphone or tablet screen before construction to visually confirm discrepancies with the existing conditions.

Combining these functions, LRTK dramatically improves information sharing and inspection efficiency at solar construction sites. Point clouds and survey data captured on site are stored in the cloud and instantly shared with office managers and design staff. Being able to confirm alignment between design drawings and actual installations with a single smartphone shortens verification tasks and reduces variability in construction quality. AR displays also help visually explain and build consensus with owners and inspection agencies.

Introducing LRTK enables a shift away from personnel-dependent, analogue solar construction site management toward the next-generation DX site. Leverage the benefits of 3D visualization with point cloud scanning—reduced manpower, design and as-built difference management, inspection efficiency, and smartphone compatibility—to improve construction productivity.