The Future of Solar Power Plant Design: A New Norm for Using PVsyst with iPhone × LRTK

The design of solar power plants has been undergoing significant change in recent years due to advances in technology. In particular, the combination of the iPhone and LRTK (high-precision GNSS positioning device) has made acquiring high-precision terrain information that was previously difficult much more accessible. By using the detailed terrain data and point cloud data obtained in design simulation software such as PVsyst, improvements in system design accuracy and power generation efficiency can be expected. This article explains the advantages of using terrain information obtained with iPhone × LRTK in PVsyst, a concrete implementation flow, and the future prospects of this new approach, with comparisons to conventional solar power design methods.

PVsyst and the Current State of Solar Power Design

PVsyst is software widely used for designing solar power systems and simulating their energy production. Users input panel capacity, layout, meteorological data, and other parameters to analyze annual energy production, efficiency, the impact of shading, and more in detail. It has become an indispensable tool for optimizing system design across projects ranging from large utility-scale (mega-solar) sites to small and medium-sized solar plants.

However, in traditional workflows, the accuracy of on-site terrain data and obstruction information used in PVsyst design could be a limiting factor. Typically, evaluations of site slope and shadowing from surrounding forests or buildings are based on elevation data from maps, aerial photographs, or information obtained through simple on-site surveys. If these data are coarse or contain large errors, there is a risk that simulation results will diverge from actual power production. This is especially true for installations on sloped land: without terrain-adapted design, optimization of the solar incidence angle and prevention of shading between adjacent panels may be insufficient, which can lead to reduced generation efficiency.

Challenges of Conventional Design Methods and Terrain Data Acquisition

In conventional solar power plant design processes, obtaining detailed terrain information required on-site surveying by licensed surveyors or specialist contractors. The typical workflow uses total stations or GNSS surveying instruments to measure land elevations and boundaries, then produces contour maps and cross-sections to inform the design. However, this approach had several challenges:

• Cost and time burden: Professional surveying requires expensive equipment and skilled personnel, which can be a heavy burden for small projects or those with limited budgets. Additionally, there can be a significant delay from performing the survey to receiving the data, creating a bottleneck in the design schedule.

• Limits of data accuracy and density: Traditional surveys infer terrain from discrete survey points, so when point spacing is wide, fine undulations or local depressions and embankments can be overlooked. Small irregularities that affect the layout of panel rows are not negligible because they can influence generation efficiency. However, obtaining high-density survey points manually has practical limits.

• Poor updateability: If design changes or site earthworks occur at a development site, re-surveying is required. With conventional methods, it is difficult to frequently update the current conditions, making it hard to immediately reflect the latest situation in the design.

Because of these challenges, solar designers sometimes had no choice but to rely on simplified terrain models or publicly available elevation data, leaving uncertainties in design accuracy and post-installation generation forecasts.

A Revolution in High-Precision Terrain Data Acquisition with iPhone × LRTK

The recently introduced combination of LRTK (smartphone-mounted RTK positioning device) and iPhone is establishing a new standard for terrain data acquisition on solar design sites. RTK (Real-Time Kinematic) is a technique for correcting GNSS (Global Navigation Satellite System) positioning errors in real time, which traditionally required antennas, base stations, and other specialized equipment. LRTK integrates these elements into a compact unit that, when mounted on a smartphone, can achieve centimeter-level positioning accuracy. By linking with smartphones like the iPhone and using dedicated apps, high-precision coordinates can be obtained in real time.

Equally noteworthy is the integration with the LiDAR sensor—recent iPhones include built-in LiDAR that can rapidly scan the surrounding environment in 3D. Leveraging this enables the capture of point cloud data (datasets of numerous points representing 3D shapes) of terrain and structures. Combining the high-precision positional information from the LRTK device with LiDAR’s detailed shape scanning allows creation of high-precision 3D terrain data in which each point has latitude, longitude, and elevation information.

For example, a technician walking across a prospective plant site with an iPhone fitted with an LRTK device can collect point cloud data that includes subtle surface undulations. Irregularities on the order of centimeters to tens of centimeters that were often missed in the past can be recorded in detail using this method. LRTK apps often provide AR (augmented reality) navigation to guide scanning, enabling even less experienced staff to intuitively capture the required coverage. After data capture, point clouds can be uploaded from the phone to cloud services and visualized or edited on a PC.

This smartphone-complete high-precision surveying approach is revolutionary because it is quick and simple while offering accuracy comparable to conventional surveying equipment. A single person can often complete surveying in a short time; in some reports, scanning large sites can be finished in 5–10 minutes. Because every point in the collected point cloud is assigned world coordinates (absolute coordinates), the data can be overlaid directly onto design drawings or other spatial data, which is a major advantage.

Data and Technical Features Obtainable with LRTK

Here is a summary of the main types of data and technical features that can be obtained with smartphone surveying using LRTK.

• High-precision positioning coordinates: LRTK devices include high-performance GNSS antennas and receivers and enhance real-time positioning accuracy using Michibiki (QZSS) CLAS and network-based RTK correction information. As a result, location information that would have had meter-level errors with conventional smartphone GPS can be improved to centimeter-level or better. When determining panel installation positions, this accuracy provides precise coordinates including elevation for any location within a parcel, supplying reliable input values for PVsyst simulations described later.

• Point cloud data (3D models): Scanning the environment with a smartphone’s LiDAR and camera records the surroundings as point cloud data comprising tens of thousands to millions of points. Each point includes the high-precision positional coordinates mentioned above, so the result is not just a shape model but a measured 3D terrain model. From this, fine surface irregularities, slope angles, and the locations of trees or existing structures within the site can be understood. Point clouds can be viewed and edited on the LRTK cloud, and it is easy to remove unnecessary points (e.g., temporary moving objects) or perform coordinate transformations.

• Photographs and textures: If needed, photos taken with the iPhone’s high-performance camera can be tagged with high-precision position data. These photos can support photogrammetry post-processing to assist 3D model generation or be used to texture point clouds for clearer visualization. For example, recording the ground surface condition—whether grass, gravel, etc.—with photos makes it intuitive to understand “what is at each location” when combined with a point cloud model.

All of the above data can be collected with just a smartphone and an LRTK device, and data are immediately saved and shared via the cloud. This allows on-site terrain models to be shared with stakeholders back at the office and used in design meetings.

How to Import Point Cloud Data Captured by a Smartphone into PVsyst

Now let’s look specifically at how terrain information and point cloud data acquired with LRTK + iPhone can be leveraged in PVsyst design. PVsyst has a 3D simulation environment called "Near Shadings," where terrain and surrounding structures around panels can be modeled to calculate solar shading effects. Reflecting detailed on-site terrain in this environment enables more accurate energy yield predictions.

1. Data format conversion: Point cloud data obtained from LRTK apps or the cloud can be exported in common point cloud formats (e.g., LAS, PLY) or as elevation data (digital elevation models in GeoTIFF or XYZ coordinate CSV files). PVsyst cannot directly read point cloud data, but it can import elevation points with coordinates (CSV format) or GeoTIFF. From the acquired point cloud, extract appropriate surface points and thin the data as needed to create a CSV list of "X coordinate, Y coordinate, Z (elevation)."

2. Importing terrain data into PVsyst: In PVsyst’s 3D scene screen, select "File > Import > Import ground data (CSV, TIF)" from the menu and specify the CSV (or GeoTIFF) file. If the import succeeds, a terrain object (ground mesh) will be automatically generated based on the points in the CSV. PVsyst creates a triangular irregular network (TIN) from the point distribution to reproduce the terrain. For very large sites with a huge number of points, automatic data simplification (thinning) may be suggested, but if the original point cloud is high-density, some thinning will still result in a sufficiently detailed terrain model.

3. Scene scaling and alignment: The imported terrain model can be positioned and rotated as desired within PVsyst. Typically, data obtained in a local coordinate system (latitude/longitude or planar coordinates) require alignment with the project origin used in PVsyst. Even when using absolute-coordinated point clouds from LRTK, you can set reference points in PVsyst to accurately match the surveyed coordinate system with the design coordinate system. For example, you can set one corner of the site as the origin (0,0,0) and reposition the entire terrain accordingly.

4. Applying to panel layout: Place the solar panel layout onto the terrain in the 3D scene. PVsyst allows installing panel rows (tables) along slopes and includes functions to automatically conform layouts to imported terrain. This ensures that each panel is placed at the correct elevation relative to the actual ground, preventing panels from floating or being buried in sloped terrains. You can fine-tune inter-row spacing and angles as needed to account for relative height differences due to terrain undulations and minimize shading occurrence.

5. Shading analysis and energy production simulation: Once the scene with terrain is complete, run time-based solar simulations. Hills around the site or local high points and depressions will cast shadows on panels at specific times, which are calculated and quantified as annual energy losses (shading losses). Using precise terrain data obtained with LRTK enables accurate assessment of local terrain-induced solar blockage, revealing small losses that would be overlooked with a rough flat model. As a result, PVsyst’s generation forecasts become closer to reality, dramatically improving the accuracy of design-stage projections.

Concrete Effects on Generation Efficiency and Design Accuracy

Here are specific ways that reflecting high-precision terrain data acquired by smartphone surveying in PVsyst improves generation efficiency and design accuracy.

• Maximizing generation through optimal layout planning: Detailed terrain models allow you to understand local slopes and aspects, enabling fine-tuning of panel tilt and row layout according to micro-terrain. For example, adjusting panel angles to match local slope variations helps each panel maintain an orientation as close to perpendicular to sunlight as possible. This evens out incident irradiance across panels and improves overall system efficiency. Appropriately spacing rows according to terrain undulations also reduces the likelihood that front rows will cast shadows on rear rows at low sun angles in the morning and evening, thereby reducing shading losses.

• Accurate energy production forecasts and investment decisions: Simulations based on precise terrain and obstruction models make it possible to estimate site-specific energy production with high accuracy. This increases confidence in annual yield and financial projections that previously had considerable uncertainty. Being able to present evidence-based forecasts grounded in measured data is a strong advantage when making investment decisions or explaining projects to financial institutions. Consequently, the risk of over- or under-sizing equipment and related losses is reduced, improving project profitability.

• Reduced design and construction risks: High-precision terrain data are useful not only in design but also during construction. For instance, you can verify in advance that the actual terrain matches the design drawings, preventing issues such as support frames not reaching the ground or being excessively elevated after installation. When earthworks are required, cut-and-fill volumes can be accurately calculated from point cloud data to optimize construction plans. These are secondary benefits that stem from improved design accuracy and contribute to lower project risk and better cost control.

• Fewer site visits and faster design revisions: With smartphone-based surveying, designers can acquire on-site data whenever needed. If new buildings appear nearby during planning or extra land is acquired, you can rapidly obtain updated point cloud data and reflect it in PVsyst simulations. This speeds up design iterations and helps maintain optimal designs based on the latest information.

Workflow from Smartphone Surveying to PVsyst Design

Below is a typical procedure for acquiring terrain data with iPhone × LRTK and applying it in PVsyst design.

• Preparation for on-site smartphone surveying: Mount the LRTK device on the iPhone at the prospective plant site and launch the dedicated app. Confirm the planned survey area on the map and, if necessary, plan walking routes and photo points. Turn on the LRTK, and once GNSS positioning is stable and at centimeter-level accuracy (RTK FIX solution), you are ready.

• Conducting the terrain scan: While walking the site, the surveyor scans the surroundings with the iPhone’s camera and LiDAR sensor. At key points, hold the device steady and scan from multiple angles to capture ground surfaces and obstacles comprehensively. The LRTK app displays a real-time preview of the collected point cloud and coverage area so you can avoid gaps or excessive overlap. For large sites, you can divide the area and scan in multiple sessions to be merged later.

• Uploading and processing data: After surveying, upload the point cloud and photo data to the cloud from the app. The cloud may automatically perform post-processing (e.g., photogrammetry-based point cloud generation or noise filtering). Use the web management interface to review the data, adjust elevation references, and filter out unwanted points to prepare a terrain dataset for PVsyst.

• Importing terrain data into PVsyst: Export the terrain data from the cloud in CSV or GeoTIFF format and import it into the PVsyst project. As noted earlier, perform coordinate adjustment and rotation in PVsyst as needed to reproduce the site terrain within the scene.

• Design simulation and verification: Place panel layouts on the terrain and execute shading analysis and energy production simulations. Review the results and check for unexpected large shading losses or unacceptable efficiency drops due to slope. If necessary, revise panel layouts or plan mitigation measures for obstructions (e.g., scheduling the removal of certain trees) and iterate simulations to develop the optimal plan.

Through this workflow, surveying and design review become a digitally seamless process. In the past, design often had to wait for the completion of survey drawings, and revisions sometimes required re-surveying, creating a siloed process. Smartphone surveying enables end-to-end progress that is a major attraction of this approach.

Cost and Operational Efficiency Improvements from Adoption

The new surveying and design approach using iPhone × LRTK not only improves technical accuracy but also brings significant benefits in terms of operational efficiency and cost reduction.

• Reduced surveying costs: As noted above, there is no need for expensive surveying equipment or outsourcing; in-house technicians can complete terrain data acquisition with just a smartphone, significantly cutting surveying expenses. Because site personnel can follow app guidance to collect sufficient data, reliance on licensed surveyors is reduced, lowering labor costs.

• Shortened work time: Smartphone surveying with LRTK shortens on-site work time and dramatically reduces lead time from data acquisition to design incorporation. Cloud-based data sharing makes it possible to, for example, survey in the morning and review results in the design software in the afternoon, enabling a rapid iteration cycle and giving the project timeline more flexibility for earlier decision-making.

• Improved safety: Reducing the need to carry heavy surveying equipment across rugged terrain lowers the risk of accidents during on-site surveys. Because surveying can be done with an iPhone and a small device, staff can move quickly and safely in rough terrain. The ability to perform surveys with minimal personnel (sometimes a single person) also reduces work load in hot climates or remote locations.

• Easier data management and sharing: Survey data stored in the cloud can be shared immediately with project stakeholders, facilitating smooth collaboration during planning. Designers, construction managers, and clients can view the same data simultaneously, reducing misunderstandings and simplifying change tracking. This eliminates the need to distribute printed drawings or large point cloud files by email.

For adopting companies, these advantages translate to overall project efficiency gains and make it likely that initial investments will be recuperated.

Future Prospects: The Future Opened by Smartphone-Complete Surveying

The combination of smartphone-complete surveying with iPhone × LRTK and PVsyst has the potential to redefine the standard for solar power plant design. As devices and software continue to evolve and this approach becomes widely adopted, the following prospects are conceivable:

• Real-time integration of data collection and design: In the future, data captured by smartphones on-site could be reflected in the cloud in real time, and design software could update models immediately. Real-time collaboration—where a designer in the office runs simulations while on-site staff add missing scans—may become a reality.

• AI-driven automated design optimization: Assuming detailed point cloud data are readily available, AI tools that automatically propose terrain-optimized layouts could emerge. While PVsyst already offers certain automatic layout functions, future systems may use smartphone survey data to instantly evaluate tens of thousands of layout patterns and present the highest-efficiency plan.

• Expanded application areas: High-precision smartphone surveying will play an important role in civil engineering and construction as part of i-Construction (ICT-based construction). For solar power plants, point cloud data will increasingly be used not only in design but also for as-built verification after construction and for long-term monitoring of changes such as ground settlement or structural displacement. The practice of sharing smartphone survey data across the entire lifecycle—from design to construction and maintenance—may become standard.

In such a future, LRTK-enabled smartphone-complete surveying will be an indispensable foundational technology. A ubiquitous smartphone will function as a high-precision "surveying instrument," and when linked with advanced design tools like PVsyst, the accuracy and efficiency of solar power design will increase dramatically. This new norm is expected to spread throughout the industry and be applied across many projects. With technological progress, the future of solar power plant design looks increasingly bright.