A Must-See at the Solar Expo: Dramatically Streamline Pre-construction Surveys with Point Cloud Scans × Cloud Reporting

Introduction

As attention to renewable energy grows, large-scale solar power projects are progressing across the country. In line with this, improving on-site efficiency is an urgent issue. In particular, the site “pre-construction survey” conducted before installing solar panels (surveying and verifying current site conditions) is a crucial step that directly affects the overall project schedule and construction accuracy. Solar power plants are often built in mountainous areas or on extensive former farmland, and conventional surveying methods do not easily capture the terrain accurately down to every corner of the site. However, if terrain can be digitized in detail, it becomes much easier to plan optimal panel layouts and earthwork, and to consider shading and drainage issues in advance. Against this backdrop, a survey method combining point cloud scanning × cloud reporting is drawing attention at the Solar Expo, which showcases the latest technologies. This article explains in detail—using concrete examples—how this approach brings efficiency gains compared to traditional survey methods. If you are looking to digitally transform (DX) your solar power sites, please use this as a reference.

Conventional Pre-construction Surveys and Challenges

Traditionally, pre-construction surveys for solar power plants have relied mainly on manpower and paper drawings. Professional surveyors go into forests or fields on site, measure elevation at points with transits or GPS units, and from those measurements create contour maps and cross-sectional terrain diagrams. This method requires time and effort to measure wide areas, and depending on the spacing between survey points there is a risk of missing subtle slopes or terrain changes. Survey results are typically compiled into paper drawings and reports and distributed to project stakeholders, but this paper-based reporting makes it difficult to share a realistic sense of the site, and it’s hard to convey subtle details.

Recently, new methods such as drone surveying have emerged, allowing terrain data to be acquired from the air faster than manual methods. With drone photogrammetry you can produce orthophotos (top-down imagery) and digital terrain models, enabling a certain level of detailed terrain understanding. However, the post-processing of data captured by drones requires specialized software and high-performance PCs, and analysis can take several days. The resulting 3D models and point cloud data are also large in size, so to share them with all on-site stakeholders they usually have to be converted into static plans or PDF reports, lacking real-time capabilities and two-way interaction. In this way, traditional methods create time lags from surveying to reporting and decision-making, leaving room for efficiency improvements. If initial surveys are inadequate, issues that emerge during earthworks—such as “the slope was steeper than planned” or “there isn’t enough fill”—can force design revisions and project delays. Low survey accuracy and communication failures can become causes of significant rework in later stages.

What Are Point Cloud Scanning and Cloud Reporting?

A point cloud scan is a technique for digitally measuring terrain and structures as a collection of countless points (a point cloud) using laser sensors (LiDAR) or photogrammetry. The resulting point cloud data can be considered a three-dimensional model that faithfully reproduces the site’s slopes and features. It is like creating a complete digital copy (a digital twin of the site), allowing you to grasp fine bumps and hollows that conventional survey maps cannot fully represent. For example, using a high-performance laser scanner to measure a forested area can collect millions of points, including trees and terrain undulations, producing a realistic point cloud model that captures the site in its entirety. Furthermore, point clouds can include color information per point, reproducing the site with a photographic appearance. By georeferencing to a survey coordinate system, you can accurately overlay the data onto drawings and calculate distances and areas. Although point cloud acquisition has been possible for some time, dedicated 3D laser scanners and skilled operators were previously required, making it costly and difficult to adopt for small-scale projects. However, recent technological advances have introduced lightweight LiDAR for drones and easy scanning methods using smartphone-built LiDAR sensors, enabling low-cost, high-density 3D surveying. What used to be limited to large-scale projects can now be utilized on small- and medium-scale sites as well.

On the other hand, cloud reporting refers to uploading acquired digital site data to the cloud and sharing, viewing, and editing it via the internet among stakeholders. If point cloud data and terrain models are uploaded to a cloud platform, each person can interactively view the data from a PC or tablet web browser without needing to install specialized software. They can freely rotate and zoom the 3D model, measure lengths, areas, and volumes, and overlay CAD design drawings for review—intuitively—even by people off-site. In other words, it enables virtual site inspection on the cloud.

How On-site Surveys Change by Using Point Cloud Data × Cloud

Sharing detailed terrain data acquired by point cloud scanning via the cloud dramatically streamlines the workflow from site survey to reporting for solar power projects. The following introduces concrete benefits compared with traditional methods.

• Faster and more comprehensive data acquisition: Surveying large sites that took days manually can be completed in a short time using drone or LiDAR scans. For example, a single drone can capture aerial imagery across an entire site in just a few hours, producing point cloud data consisting of millions of points. Not only is surveying time drastically reduced, but data isn’t missed even in steep or hard-to-access areas. As a result, “missed measurements” and the need for re-survey are reduced, and accurate, comprehensive as-built data are obtained from the start. There is also a major safety benefit since people do not need to enter hazardous areas. In some cases, surveying time can be reduced to less than one-tenth of the traditional time, eliminating delays to the overall construction schedule caused by waiting for surveys. Using the latest smartphone-mounted scanners, workers can also walk the site just after earthworks to perform point cloud measurements and immediately check the results, enabling rapid feedback on the spot.

• Easier sharing and smoother consensus building: A 3D model uploaded to the cloud can be viewed by all project stakeholders—designers, construction managers, clients—so everyone examines the same data. Height differences and terrain quirks that were hard to convey with paper drawings or numeric data are immediately clear through three-dimensional visualization. For example, designers can simulate solar panel layouts on the point cloud and accurately decide “we’ll cut this hill” or “we’ll fill this valley.” Site agents and construction teams can grasp the situation more intuitively from a 3D model than from numerically dense reports, reducing misunderstandings. Because all stakeholders can exchange opinions while looking at the same digital site, consensus is reached much faster. Cloud platforms also allow direct marking and commenting on the model, so issues can be shared immediately and discussions proceed without communication loss.

• Remote site awareness and instant approvals: Point cloud data shared on the cloud is accessible from anywhere with an internet connection. This allows head office staff to virtually survey site terrain and issue additional instructions from the office. For example, head office staff in Tokyo can review measurement data from a proposed site in a remote mountain area the same day and give a remote “go” decision that the project can proceed as planned—this kind of remote approval becomes realistic. Processes that once required in-person site visits and meetings can be completed online, significantly reducing travel time and costs. Recently, combinations of point cloud data and 360-degree imagery have enabled head office staff to use VR headsets for a virtual site experience from afar. Being able to check details in a virtual environment without traveling has reportedly cut travel time dramatically. Additionally, because the situation can be visually understood without going to the site, a small number of staff can efficiently supervise multiple remote sites.

• Streamlined reporting and correction workflows: Data acquired on site can be shared via the cloud the same day, speeding up report creation. If needed, cross sections or height distribution maps can be auto-generated from point cloud data and presented immediately to stakeholders. Compared to paper reports, the volume of information that can be shown is greater, conveying site conditions in detail and reducing the need for additional explanations. When new discoveries or design changes arise, updating the data to the cloud keeps everyone on the latest version. Version control and explaining differences becomes easy, minimizing discrepancies and rework. For example, by overlaying terrain data with design models you can identify issues such as “the northern panels will be shaded as is” before construction and correct them in the design stage. Processes that previously took weeks from initial survey to design revision can be completed with point cloud data in just a few days, or even the same day, shortening the project lead time. Systems have also been developed to automatically generate inspection records (with photos) from point cloud data, enabling one-click creation of photo-inclusive reports. The effort required to create records continues to decrease.

• Advanced earthwork planning and schedule control: Detailed as-built point cloud data directly improves the accuracy of earthwork (cut-and-fill) planning. From the acquired terrain model, elevation differences and slopes can be automatically calculated to quantitatively determine where and how much soil needs to be added or removed. Even in complex terrain, comparing point cloud datasets enables instantaneous calculation of cut-and-fill volumes, more reliable than manual calculations or estimations based on experience. This prevents soil shortages or excesses and allows proper planning of heavy equipment and dump trucks. Re-scanning with drones or smartphones during earthworks and comparing current conditions with the design model allows immediate confirmation of whether finished ground elevations and slopes match the design. If color-coded elevation differences are displayed on the cloud, it’s visually clear which spots are under-excavated or overfilled, enabling immediate additional grading instructions. Repeating this feedback during construction helps prevent rework and overwork, resulting in shorter schedules and cost savings. Moreover, 3D terrain can be used to run runoff simulations to assess flood risk and plan appropriate drainage placements, supporting environmental mitigation measures in advance. Detecting problems that used to emerge after construction allows safer project execution.

• Smoother coordination with municipalities and external communications: Development of solar power plants requires consultation with local governments and explanations to residents. Point cloud data and cloud sharing are powerful tools for these processes as well. For example, when clearing forested land for earthworks, sharing cloud-based comparisons between the current 3D terrain and the post-construction finishing image helps municipal officials form a concrete image. Explaining “this valley will be filled to this extent to make it flat” or “we will install an attenuation pond here” using a three-dimensional model rather than just plan views accelerates issue identification and consensus building. Large data files don’t need to be emailed or stakeholders summoned to the site; sufficient information can be provided online, reducing time spent on administrative procedures and external coordination. Explanations based on accurate 3D materials are more persuasive and can reduce the number of rounds needed for consultations and approvals. Additionally, showing a tablet with a 3D model of the final image at a community meeting allows residents to intuitively understand the plan without technical terms.

Note that challenges such as large point cloud file sizes and specialized software operation are being steadily reduced by evolving cloud services and user-friendly apps. These technological innovations are creating an environment where even non-specialists can enjoy the benefits.

Conclusion: The Future of Solar Power Development Opened by Digital Technology

By leveraging point cloud scanning and cloud reporting, information sharing and decision-making from pre-construction surveys to construction in solar power development are dramatically accelerated. Precise survey data enables accurate construction at once, contributing to improved quality. In practice, sites that adopted this approach reported that feedback time from surveying to design was reduced to a fraction of previous durations, and rework due to design changes decreased significantly. This approach—representative of on-site DX—is attracting industry attention to the extent that it’s featured as a “must-see” topic at the Solar Expo. The Ministry of Land, Infrastructure, Transport and Tourism is also promoting the use of 3D data in construction sites, making the adoption of point cloud technology very much in line with the times. Surveying and reporting processes that used to rely on manpower and experience are transforming into systems where everyone can grasp accurate as-built conditions through digital data. As a result, limited personnel can handle multiple projects in parallel, contributing to solutions for labor shortages, shorter schedules, and cost reductions. These productivity improvements are also important measures to address severe labor shortages and comply with work-style reform regulations limiting long working hours. Furthermore, scanning the entire site as a point cloud at project completion and retaining it as a digital record aids future maintenance planning and registry creation, further reducing documentation efforts. The paper-centric style of surveying and reporting is beginning to change significantly due to digitalization. Smart survey methods using 3D point clouds and the cloud are likely to become a new standard not only for solar power but for the construction industry as a whole.

If you have the chance to see demonstrations of point cloud scanning and cloud sharing at the Solar Expo venue, be sure to experience firsthand the power of this efficiency. You will sense the benefits that digital technology brings to the field.

Finally, as a technology that makes on-site surveying more accessible, a solution combining smartphones with high-precision GNSS that allows anyone to perform precise surveying—"LRTK smartphone surveying"—has also emerged. With simple operation you can acquire 3D point clouds and share them on the cloud, greatly contributing to efficiency in small-scale site checks and routine measurement tasks. Tasks that previously required a team can be completed by one person, significantly reducing on-site burden. Adopt survey methods that utilize the latest technologies and realize DX and productivity improvements at solar power sites.