The Future of Solar PV Design: A New Norm for PVsyst Utilization Opened by iPhone×LRTK

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

PVsyst and the current state of solar PV design

PVsyst is widely used software for designing solar photovoltaic systems and simulating energy production. Users input panel capacities, layouts, meteorological data, and other parameters to analyze annual energy yield, efficiency, shading effects, and more in detail. It is an indispensable tool for optimizing system design from large-scale megasolar plants to small and medium-sized solar power stations.

However, in conventional practice, the accuracy of on-site terrain data and obstacle information used in PVsyst design has sometimes been a challenge. Typically, elevation data on maps, aerial photographs, or information obtained from simple field surveys are used to evaluate site slopes and shading from surrounding forests and buildings. If this information is coarse or contains large errors, simulation results and actual power generation may diverge. Especially when installing panels on sloped land, if the design does not conform to the terrain, optimization of solar incidence angles and prevention of shadowing between adjacent panels may be insufficient, potentially reducing generation efficiency.

Challenges in traditional design methods and terrain data acquisition

In the traditional design process for solar power plants, obtaining detailed terrain information required on-site surveying by licensed surveyors or specialist contractors. Using total stations or GNSS surveying equipment to measure land elevation differences and boundaries, then creating contour maps and cross-sectional terrain diagrams to reflect in the design was the typical workflow. However, this approach had several challenges.

• Cost and time burden: Professional surveying requires expensive equipment and skilled personnel, which can be burdensome for small projects or those with limited budgets. Also, it can take time from performing the survey to delivering the data, creating a bottleneck in the design schedule.

• Limits in data accuracy and density: Traditional surveys infer terrain from scattered survey points, so if point spacing is wide, fine undulations or local depressions and embankments may be overlooked. Small irregularities that affect the arrangement of PV panel rows can influence generation efficiency and cannot be ignored. However, there are practical limits to obtaining high-density points with human resources alone.

• Low update frequency: If design changes or earthworks occur at a development site, re-surveying is required. With conventional methods it is difficult to casually update the current state many times, making it hard to immediately reflect the latest conditions in the design.

Because of these challenges, solar PV designers have sometimes had to rely on simplified terrain models or publicly available elevation data, leaving uncertainty in design accuracy and post-construction power generation estimates.

The revolution in high-precision terrain data acquisition with iPhone×LRTK

The combination of recently introduced LRTK (smartphone-mountable RTK positioning device) and the iPhone is bringing a new standard for terrain information acquisition to solar PV design sites. RTK (real-time kinematic) is a technology that corrects GNSS (global navigation satellite system) positioning errors in real time, and traditionally required antennas and base stations or other specialized equipment. LRTK integrates these into a compact unit, and by simply attaching it to a smartphone it can achieve centimeter-level positioning accuracy (half-inch accuracy). When paired with a smartphone such as an iPhone and used with a dedicated app, high-precision position coordinates can be obtained in real time.

Another notable aspect is the integration with the LiDAR sensor that recent iPhones incorporate. Modern iPhones include LiDAR capable of rapidly 3D-scanning the surrounding environment, enabling acquisition of point cloud data (data that represents 3D shapes as a collection of numerous points). By combining high-accuracy position information from the LRTK device with the detailed shape scans from LiDAR, it becomes possible to obtain high-precision 3D terrain data where each point has latitude, longitude, and elevation information.

For example, a technician walking a planned PV site with an iPhone fitted with an LRTK device can collect point cloud data that includes subtle ground undulations. Irregularities on the order of several centimeters to several tens of centimeters (a few inches to a few dozen inches) that were often overlooked in the past can be recorded in detail using this method. The LRTK app can also provide AR (augmented reality) navigation, allowing even less-experienced surveyors to intuitively scan the necessary area. After data acquisition, point cloud data can be uploaded from the phone to cloud services and visualized and edited on a PC.

This smartphone-complete high-precision surveying approach is revolutionary because it is quick and easy while offering accuracy comparable to conventional surveying equipment. One person can complete surveying in a short time, and there are reports of large sites being scanned in about 5–10 minutes. Because all acquired point clouds are tagged with world coordinates (absolute coordinates), they can be overlaid directly onto design drawings and other spatial data for immediate use.

Data obtainable with LRTK and technical characteristics

Below is a summary of the main data and technical characteristics obtainable through smartphone surveying using LRTK.

• High-precision positioning coordinates: LRTK devices have built-in high-performance GNSS antennas and receivers that use Michibiki (QZSS) CLAS and network-type RTK correction information to improve positioning accuracy in real time. As a result, location information that had errors of several meters with conventional smartphone GPS improves to errors of a few centimeters or less. When considering the placement of solar panels, this level of accuracy provides precise coordinates including elevation differences anywhere within a parcel, supplying highly reliable input values for PVsyst simulations described later.

• Point cloud data (3D models): Scans of the surrounding environment acquired by the phone’s LiDAR and camera are recorded as point cloud data comprising tens of thousands to millions of points. As noted above, each point includes high-precision position coordinates, so this is not merely a shape model but a measured 3D terrain model. From this, fine surface irregularities, slope angles, and the positions of trees or existing structures on the site can be understood. Point cloud data can be viewed and edited on the LRTK cloud, allowing easy removal of unwanted points (such as temporary moving objects) and coordinate transformations.

• Photographs and textures: If needed, photos taken with the iPhone’s high-performance camera can be tagged with high-precision location data. These photos can be used in post-processing for photogrammetry to help create 3D models, or to provide color (texture) information to point clouds for clearer visualization. For example, recording the ground surface as grass or gravel in photographs, combined with the point cloud model, makes it intuitive to know “what exists at which point.”

All of the above data can be acquired with just a single smartphone and an LRTK device, and the data are saved and shared to the cloud immediately. This makes it easy to share the terrain model captured on-site with stakeholders in the office and use it in design meetings.

How to import smartphone-acquired point cloud data into PVsyst

Now let us look at how terrain information and point cloud data acquired with LRTK+iPhone can be concretely utilized in PVsyst design. PVsyst has a 3D simulation environment called “Near Shadings,” where terrain and nearby structures around panels can be modeled and their shading effects computed. Reflecting detailed on-site terrain here enables more accurate energy yield predictions.

• Data format conversion: Point cloud data obtained from the LRTK app or cloud can be exported in common point cloud formats (LAS or PLY) or elevation data (GeoTIFF digital elevation model, or CSV files of XYZ coordinates). PVsyst cannot read raw point cloud data directly, but it can import elevation points with coordinates (CSV format) or GeoTIFF. From the acquired point cloud, extract only the points representing the land surface and decimate them appropriately to create a CSV list of “X coordinate, Y coordinate, Z (elevation).”

• Loading terrain data into PVsyst: In PVsyst’s 3D scene screen, select “File > Import > Import ground data (CSV, TIF)” from the menu, and specify the above CSV or GeoTIFF file. If loading succeeds, PVsyst automatically generates a terrain object (ground surface mesh) from the points in the CSV. PVsyst creates a triangular irregular network (TIN) from the point distribution to reproduce undulations. If the site is very large and the point count is extremely high, PVsyst may suggest automatic data simplification, but if the original point cloud is dense, some decimation usually still yields a sufficiently detailed terrain model.

• Scene scale and alignment: The imported terrain model can be moved and rotated as needed within PVsyst. Typically, data acquired in a local coordinate system (latitude/longitude or plane coordinates) must be aligned with the project origin in PVsyst. Even with absolute-coordinate point clouds obtained by LRTK, you can set reference points in PVsyst to accurately match the survey coordinate system with the design coordinate system. For example, you can place a corner of the site at the origin (0,0,0) and reposition the entire terrain accordingly.

• Applying to panel layout: On the terrain-loaded 3D scene, place the PV panel layout. PVsyst allows arranging panel rows (tables) along slopes and has features to automatically conform layouts to imported terrain models. This ensures that each panel is placed according to actual ground elevation and is not modeled as floating or buried on slopes. You can fine-tune row spacing and tilt angles as needed and consider relative height differences due to topography to minimize shadowing.

• Shading analysis and energy yield simulation: Once the scene including terrain is completed, run time-series solar simulations. Hills around the site or high and low ground within the site will cast shadows on the panels at specific times, and PVsyst quantifies annual energy losses (shadow loss) accordingly. Using the precise terrain data acquired by LRTK enables accurate evaluation of solar occlusion caused by local topography, revealing small losses that a coarse flat model would miss. As a result, PVsyst’s yield estimates become closer to reality and forecasting accuracy at the design stage increases dramatically.

Specific effects on generation efficiency and design accuracy

Below are concrete ways that reflecting high-precision terrain data obtained by smartphone surveying in PVsyst improves generation efficiency and design accuracy.

• Maximizing yield through optimal layout planning: Detailed terrain models reveal slopes and aspects, allowing panel tilt and row layouts to be optimized to local micro-topography. For example, adjusting panel tilt to reflect local slope variations helps maintain each panel as close to perpendicular to sunlight as possible, evening out incident irradiance and improving system-wide efficiency. Appropriately spacing rows according to undulations reduces the likelihood of front rows casting shadows on rear rows during low sun angles in morning and evening, thereby reducing shading losses.

• Accurate yield forecasting and investment decisions: Simulations using precise terrain and shading models make it possible to estimate site-specific generation with high accuracy. This builds confidence in annual energy and financial forecasts that were previously estimated with uncertainty. Being able to provide evidence-based forecasts grounded in measured data is a major advantage when making investment decisions or explaining projects to financial institutions. Consequently, the risk of over- or under-sizing equipment is reduced, improving project profitability.

• Reduced design and construction risk: High-precision terrain data are useful not only in the design stage but also during construction. For example, verifying in advance that real terrain matches the design prevents surprises such as racking not reaching the ground or being excessively elevated. When earthworks are required, cut-and-fill volumes can be accurately calculated from point clouds, enabling optimized construction planning. These are secondary benefits enabled by improved design accuracy that ultimately reduce project risk and improve cost control.

• Fewer site visits and rapid design revisions: Smartphone-complete surveying allows designers to obtain on-site data as often as needed. For instance, if information arises about a new building near the project during planning or additional land is acquired, you can quickly acquire up-to-date point cloud data and reflect it in PVsyst simulations. This dramatically speeds up design revisions and helps maintain optimal designs based on the latest information.

Workflow from smartphone surveying to PVsyst design

Here is a typical procedure to acquire terrain data with iPhone×LRTK and use it in PVsyst design.

• Preparation for smartphone surveying on site: Mount the LRTK device on the iPhone at the planned PV site and launch the dedicated app. Check the approximate survey area on the map and plan walking routes or capture points as needed. Turn on the LRTK, and when GNSS positioning stabilizes to centimeter-level accuracy (RTK FIX solution), you are ready.

• Conducting the terrain scan: The surveyor walks the site while pointing the iPhone’s camera and LiDAR sensor to scan the surroundings. At key points, hold the device slowly and from multiple angles to capture the ground surface and obstacles thoroughly. The LRTK app displays a real-time preview of acquired point clouds and coverage, helping avoid gaps or unnecessary overlap. For large sites, divide the area and scan multiple sections to be merged later.

• Uploading and processing data: After surveying, upload the acquired point cloud and photo data from the app to the cloud. Cloud-side post-processing (for example, point cloud generation via photogrammetry or noise removal) may be performed automatically. Use the web management interface to check 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 described above, perform coordinate adjustments or rotation in PVsyst as required to recreate the on-site terrain in the scene.

• Design simulation and verification: Set the panel layout on the terrain and run shading analysis and energy simulations. Review the results to check for unexpected shading losses or efficiency reductions due to slopes. If necessary, revise the panel layout or plan measures to mitigate obstacles on the terrain (for example, schedule selective tree removal) and iterate simulations to develop the optimal plan.

This flow enables a digitally seamless workflow from field surveying to design review. Traditionally, designers had to wait for survey maps to start design and might need re-surveys for each design change, creating siloed processes. Smartphone surveying enables end-to-end progress in one continuous workflow.

Cost and operational efficiency improvements from adoption

The new surveying and design method using iPhone×LRTK provides not only technical accuracy improvements but also substantial benefits in operational efficiency and cost reduction.

• Reduced surveying costs: As noted, expensive surveying equipment and outsourcing are unnecessary; in-house technicians can complete terrain data acquisition with a smartphone, significantly compressing surveying expenses. Without engaging licensed surveyors, site personnel can obtain adequate data simply by following the app’s guidance, reducing labor costs.

• Shortened work time: LRTK smartphone surveying reduces on-site work time and drastically shortens lead time from data acquisition to design reflection. With cloud-based data linking, data collected in the morning can be reviewed in design software the same afternoon, enabling a rapid cycle. This provides slack in the overall project timeline and allows for faster decision-making.

• Improved safety: Because heavy surveying equipment and repeated trips across uneven terrain are no longer required, on-site accident risk decreases. Surveying with just an iPhone and a small device allows nimble and safe movement even on poor footing. The ability to survey with the minimum necessary personnel (sometimes just one person) reduces workload in hot environments and in remote locations.

• Easier data management and sharing: Survey data stored in the cloud can be shared with project stakeholders instantly, facilitating smooth collaboration. Designers, construction managers, and even clients can view the same data during discussions, reducing misunderstandings and simplifying change-history management. This eliminates the need to send paper drawings or large point cloud files by email.

For adopting companies, these improvements contribute to overall project efficiency, and the value typically justifies recouping the initial investment.

Future prospects: the future unlocked by smartphone-complete surveying

The combination of smartphone-complete surveying with iPhone×LRTK and PVsyst has the potential to redefine standards for solar PV 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 a smartphone on-site may be reflected in the cloud in real time and models on the design software side updated immediately. Real-time collaboration—where a designer in the office runs simulations while field staff add missing scans—may become feasible.

• AI-driven automated design optimization: Assuming detailed point cloud data are available, AI tools that automatically propose layouts optimized for the terrain may emerge. PVsyst already offers certain automatic placement features, but in the future AI could evaluate tens of thousands of layout permutations instantly using smartphone survey data and present the most efficient plan.

• Expanded application areas: High-precision smartphone surveying will play a key role in i-Construction (ICT-enabled construction) across civil engineering and construction beyond solar PV. For solar plants, point cloud data use is expected to expand into construction quality control (verifying that the build matches the design) and lifecycle monitoring (detecting ground subsidence or structural displacement over time). The trend toward sharing and using smartphone survey data across design, construction, and maintenance phases may become established.

In such a future, simple smartphone-complete surveying with LRTK will be an indispensable foundational technology. A smartphone in everyone’s hand becomes a high-precision “surveying instrument,” and when linked with advanced design tools like PVsyst, the accuracy and efficiency of solar PV design will dramatically improve. As this new norm spreads through the industry, it will likely be applied in an increasing number of projects. With technological progress, the future of solar PV design looks increasingly bright.