New Technology Drawing Energy Industry Attention: Using iPhone Survey Data in PVsyst Analysis with LRTK

Technological Innovation in the Renewable Energy Sector and the Emergence of Smartphone Surveying

In the renewable energy field, particularly in solar power projects, there is constant demand for improving efficiency and accuracy in the design and construction processes. In Japan, efforts to expand the adoption of renewable energy are progressing toward achieving carbon neutrality by 2050, and plans for building solar power plants are increasing year by year. Along with this, introducing new technologies to carry out projects quickly and reliably is becoming ever more important. Recently, a new technological trend—surveying using smartphones (iPhone)—has attracted attention. Traditionally, surveying required specialized surveying instruments and teams of several people, but now, by combining a smartphone with a small device, high-precision positioning by a single person is possible. This innovative surveying method is having wide-ranging impacts from design to construction in renewable energy projects.

As part of the digitalization of surveying, aerial photogrammetry using drones and laser measurement have also become widespread in recent years. However, drones are not always freely deployable at every site due to aviation law permit requirements, weather and time constraints, and no-fly zones. In that respect, smartphone surveying, which can be used easily on the ground, is powerful in environments where drones are difficult to operate, such as urban areas, forests, and confined sites. Because people can directly measure small differences in ground elevation and narrow spaces, it is possible to obtain on-site data that covers details thoroughly.

What is particularly attracting attention in the energy industry is the fusion of smartphones with RTK (real-time kinematic) technology. RTK is a method that uses GNSS (global navigation satellite systems) to achieve centimeter-level positioning accuracy (half-inch accuracy), and it once required expensive equipment. However, in recent years, compact RTK-capable devices called LRTK have appeared, allowing easy connection to smartphones like the iPhone. This has enabled on-site “simple surveying” with a smartphone, greatly reducing the workload compared to traditional methods.

What is PVsyst: The Standard Tool for Solar Power Simulation

An indispensable destination for utilizing such survey data is PVsyst. PVsyst is simulation software widely used worldwide for designing solar power systems and forecasting generation. By inputting panel layouts, meteorological data (annual irradiation and temperature), and system configuration (module and inverter specifications), PVsyst can analyze annual energy production and loss factors in detail. PVsyst is particularly strong in shadow analysis (analysis of generation losses due to shading), and it can reflect the impact of nearby buildings, trees, and terrain shadows in simulations.

To perform highly accurate simulations with PVsyst, the quality of input data is extremely important. For example, if layout between modules, terrain information for sloped sites, and the positions and heights of surrounding obstructions are not accurate, the generation forecast will contain errors. Therefore, accurately acquiring and reflecting on-site survey data is the key to reliable solar power simulation. In recent years, the use of 3D surveying (precision measurement via drone aerial photography or terrestrial laser scanning) has also been expanding to improve simulation accuracy. For that reason, the ability to efficiently obtain site data with a smartphone is highly significant.

Benefits of Acquiring Survey Data with iPhone + LRTK

The latest iPhones are equipped with a LiDAR scanner (an optical distance-measuring sensor) that can 3D-scan the surrounding environment and obtain point cloud data. This in itself is revolutionary, but by combining it with an LRTK device, it becomes possible to attach accurate position coordinates (absolute coordinates) to the acquired data. Conventional smartphone GPS had errors of several meters (several ft), but by using RTK you can determine positions with surveying-equipment-level accuracy within a few centimeters (a few in).

Surveying with an iPhone + LRTK offers the following benefits:

• Labor savings: Surveying can be performed with just one smartphone and a small device, eliminating the need for bulky equipment or multiple personnel. Measurements can be started quickly on-site when needed, shortening investigation lead time.

• High accuracy: The centimeter-level accuracy (half-inch accuracy) provided by RTK is sufficient for designs requiring the precision of solar panel layout. Vertical measurements are also highly accurate, so subtle slopes and elevation differences are reflected in the data.

• Real-time: Acquired survey data is plotted on the smartphone screen on-site, allowing immediate verification for omissions or errors. Cloud integration enables instant sharing with the office so designers can use the data right away.

• Earthwork quantity calculation: Cut-and-fill volumes can be automatically calculated from the acquired terrain data. This allows immediate understanding of how much land shaping (grading) is needed, aiding consideration of construction costs and design plans.

• Multifunctionality: Using an LRTK-compatible app enables single-point positioning, continuous positioning (walking while continuously measuring), automatic geotagging of photos, and even 3D scanning using the iPhone’s LiDAR in one workflow. All acquired point clouds and photo data are saved with location information, making it easy to recreate on-site conditions in 3D later in design software.

Concrete Ways to Use Survey Data for PVsyst Analysis

So how can the high-precision survey data obtained in this way actually be used in PVsyst’s design and analysis processes? Let’s look at the main application points in detail.

Layout optimization by importing terrain data

Understanding site terrain (elevation differences, slopes, undulations) is indispensable for layout design of solar power plants. If you create a terrain model of the site from data surveyed with iPhone + LRTK, you can import it into PVsyst as terrain data. Specifically, by compiling survey point latitude, longitude, and elevation data into a CSV file and importing it via PVsyst’s import function, you can reproduce the site’s 3D shape. Based on this terrain model, for sloped sites you can set appropriate row spacing, prioritize placement in areas with higher irradiation, and otherwise optimize layout. Also, adjusting racking heights to match undulations can keep panels at a uniform height above the ground and provide decision support to reduce unnecessary grading (land flattening).

Measuring obstructions and improving shadow analysis accuracy

For PVsyst’s strong point—shadow analysis—it is necessary to input shading factors (objects that cast shadows around the panels) accurately. Using iPhone + LRTK surveying, you can accurately measure the positions and heights of buildings, trees, utility poles and wires on-site. For example, for trees near the site, you can obtain not only trunk positions and heights but also the crown (branches and foliage) spread as point cloud data via the iPhone’s LiDAR scan. Using this information, you can create 3D obstruction models in PVsyst and reproduce their spatial relationships with the solar panels. PVsyst can calculate time-dependent shading along the sun’s path, so models based on measured data allow more accurate estimation of generation losses due to shading. Because solar altitude varies by season, objects that are not problematic in summer can cast long shadows in winter. Detailed models created from measured data make it possible to evaluate these seasonal variations and consider optimal layouts throughout the year. In addition, panels affected by shading do not only receive less irradiance; electrical mismatch losses can also occur across the system. PVsyst can account for these effects in its generation calculations, so the accuracy of shading input data becomes even more important.

Furthermore, centimeter-accurate positioning enabled by LRTK faithfully reproduces relative relationships with surrounding terrain and objects. If you measure the height of adjacent buildings or the height of boundary walls on-site, even minor shading factors will not be overlooked. Accurate shadow analysis minimizes the risk that “generation drops due to shading not anticipated at planning” will occur later.

Feedback to design and iterative verification

Survey data acquired with a smartphone can be fed directly back into the design process. Shortening the cycle from surveying to design implementation makes it easier to perform multiple layout pattern evaluations. For example, you can run generation simulations in PVsyst using the imported site terrain and, based on the results, rapidly iterate changes to panel placement. Areas that were previously substituted with map data or coarse elevation data can now be validated by measured data, enabling more accurate decision-making from the design stage.

Because survey points can be linked to photos and notes, designers can clearly understand “what was at which point” on their desks. For instance, recording on survey point data that “a high-voltage line runs along the northwest corner of the site” or “there are deciduous tall trees to the south that leaf out seasonally” ensures such site considerations are reflected in the design. This close integration of field information and design contributes to overall project quality improvement.

New Dimension of Design Visualization Using AR Technology and Point Cloud Data

Another advantage of combining iPhone and LRTK is visualization through integration with AR (augmented reality) technology and point cloud data. By combining high-precision positioning with AR, you can overlay digital design plans onto the real landscape. For example, by turning a layout created in PVsyst into a 3D model and displaying it in AR through an iPhone screen on the actual site, stakeholders can intuitively grasp the post-completion image. Because LRTK’s precise positioning aligns virtual panels on-site with centimeter-level accuracy, you can verify installation space, aesthetics, and landscape considerations on the spot. Using LRTK’s coordinate guidance function, you can also navigate on-site to positions specified in the design drawings. This makes it possible to accurately mark planned panel locations and cable burial routes, preventing rework during construction.

Meanwhile, there is growing use of the on-site 3D model obtained as point cloud data during the design phase. Point clouds acquired by the iPhone’s LiDAR and LRTK include detailed shapes of not only the ground surface but also structures and vegetation. Importing this into CAD or BIM tools allows reproduction of the pre-design site as a digital twin. Simulating panel placement on the digital twin and fine-tuning it while comparing generation simulation results makes design optimization more realistic. A cycle of projecting completed design data back onto the site via AR for confirmation enables rigorous project verification by alternating between digital and real.

Improved Project Efficiency from Labor Reduction and Higher Accuracy

The labor savings and increased accuracy enabled by smartphone surveying dramatically enhance the overall efficiency of solar power projects. Reducing the time and personnel spent on surveying allows more resources to be devoted to design study and adjustment. Because plans are made from the start using high-accuracy data, design changes and rework in later stages are reduced, ultimately lowering project costs. For large-scale mega-solar projects, the larger the site area, the greater the surveying workload; however, by using smartphones and LRTK, data can be aggregated efficiently area by area while progressing the plan.

For example, when planning a mega-solar installation on a vast sloped site, smartphone surveying has made it possible to grasp elevation differences in detail and design layouts that minimize necessary grading. In some cases, previously overlooked local high spots were detected in advance, and by adjusting the layout to account for their impact, annual generation was improved by several percent. Additionally, calculating earthwork volumes before construction allowed optimization of heavy equipment and material arrangements, resulting in shortened construction periods and cost reductions. The combination of smartphone survey data and PVsyst analysis is a good example of achieving both risk reduction and performance improvement for projects.

Moreover, the high-precision data obtained also serves as material to stakeholders (investors, power utilities, etc.) in the form of increased reliability of generation simulations. Generation forecasts and shading-impact data shown by detailed simulations provide objective evidence that supports project feasibility, speeding up decision-making and facilitating financing negotiations.

The New On-Site Landscape Opened by Smartphone-Only Surveying “LRTK”

As introduced in this article, smartphone-only surveying with iPhone and LRTK brings many benefits to the design and development process of solar power plants. A workflow that can consistently be handled by a smartphone, from surveying to simulation and even AR visualization, is a prime example of DX (digital transformation) in the energy industry. This technological innovation, which reduces on-site burdens while improving accuracy, has the potential to become the standard for future renewable energy projects.

The smartphone surveying solution LRTK, which overturns conventional wisdom, has made “anyone, anytime, anywhere” high-precision on-site data acquisition possible. For solar power designers and engineers, the ease and reliability offered by LRTK will be a powerful tool. If you are about to work on planning or simulating a solar power plant, why not consider this smartphone-only surveying option? The combination of precise field data and PVsyst analysis should strongly support the pathway to project success.