PVSyst Japanese Translation Basic Settings: How to Utilize LRTK Survey Data

Introduction

An indispensable tool for designing and estimating the energy yield of photovoltaic systems is PVSyst. PVSyst is a world-standard PV simulation software that can calculate energy generation with high accuracy by inputting meteorological data, panel layouts, and more. However, because much of the interface and documentation are in English, it can be a high barrier for beginners in Japan. This article serves as a basic settings guide for the PVSyst Japanese translation, explaining in an easy-to-understand manner from initial setup to panel configuration, tilt and azimuth settings, and shading configuration. It also discusses the importance of on-site survey data—which is a key to improving simulation accuracy—and the limitations of manual settings, and introduces how to utilize the high-precision surveying solution LRTK. This makes the content useful for those seeking information about the PVSyst Japanese translation.

PVSyst Basic Settings Guide (with Japanese translation)

The basic configuration items for running a PV system simulation in PVSyst are explained here in Japanese. If you are using PVSyst for the first time, set up your project by following the steps below.

Initial setup: project and meteorological data input

First, start PVSyst and create a new project. Specify the “Project Name（プロジェクト名）” and set the folder to save the project. Then choose the system type (grid-connected or off-grid). Next, define the site location (installation site). Specifically, you can specify the plant location by latitude and longitude or select from city names included in PVSyst. The appropriate meteorological data for the location is also set here. For example, you can obtain the region’s annual irradiance and temperature data from datasets such as Meteonorm, SolarGIS, or NEDO. Since irradiance values differ between meteorological datasets, it is advisable to compare multiple sources and choose the one that best reflects reality. By setting appropriate meteorological data, PVSyst can accurately reflect the annual solar conditions at that site in the simulation.

Panel configuration and system specifications

Next, configure the photovoltaic system. Select the PV modules (panels) and inverters from PVSyst’s internal database and add them to the system. Major specifications such as the module’s rated output and conversion efficiency, and the inverter’s rated capacity and European efficiency, are automatically populated. Then define how the modules will be connected. Specifically, set the “number of modules in series (number of modules connected in series)” and the “number of parallel strings (number of strings)” to determine the total number of panels in the array. This calculates the system’s DC capacity and allows you to check the DC/AC ratio (oversizing ratio) in relation to the number of inverters. You can also configure system loss parameters such as wiring losses and transformer losses if needed, but beginners may leave the default values. Up to this point, the panels, inverters, and overall system size have been defined in PVSyst.

Tilt angle and azimuth angle settings

Setting the tilt angle (Tilt angle) and azimuth angle (Azimuth angle) is an important step to specify which direction the panel surface faces and at what angle it is tilted. The tilt angle indicates how many degrees the panel is raised from the horizontal plane; in Japanese it is expressed as “傾斜角” or “傾斜度”. For example, a tilt angle of 0° is horizontal and 90° is vertical. Generally, an angle near the installation latitude maximizes annual yield, but the optimal angle varies depending on installation conditions. The azimuth angle indicates the compass direction the panel faces. Azimuth is usually defined with true south as 0° (or 180°) and expressed as ± toward east-west (in PVSyst the default is true south = 0° with positive angles to the west). For example, for a due-south installation, Azimuth = 0°; due east is -90°; due west is +90°. In many cases in Japan, panels are oriented due south or slightly west of south. Correctly setting the tilt and azimuth angles ensures that the irradiance conditions for the panel layout are reflected in the simulation. If you use a tracking system, PVSyst allows 1-axis or 2-axis tracking settings, but for beginners it is recommended to start with a fixed rack.

Shading settings (horizon and near objects)

Configuring shading is also an important PVSyst function that affects PV generation. Shading factors can be broadly divided into two types: shading caused by distant terrain and shading caused by nearby objects.

Shading from the horizon (Horizon) refers to distant terrain features such as mountains or ridges on the horizon that block sunlight. In PVSyst you can set the horizon profile as the elevation angle of the horizon for each azimuth. For example, if a mountain range surrounds the site to the southwest, entering the horizon elevation angle for that azimuth reflects the times during morning and evening when the sun is in the mountain’s shadow. Horizon data can be obtained by taking all-sky photos with a fisheye lens camera on site or by calculating it from survey data, but since it is difficult for beginners to prepare immediately, you can initially assume a flat horizon (0°) if the surrounding terrain is flat.

Shading from near objects (Near Shadings) refers to shadows cast by structures, trees, utility poles, other panel rows, and other obstacles within or just around the plant area. PVSyst’s 3D Scene function enables modeling such nearby objects three-dimensionally for detailed shading analysis. Specifically, on the “Shading Scene Construction” screen you can place the panel array as a 3D model and add surrounding buildings and trees as objects by specifying their height and position. For example, if there is a tree 10 m (32.8 ft) high on the southeast side, placing it as a 3D object will allow PVSyst to calculate the impact of that tree’s shadow on the panels throughout the year. PVSyst calculates the shading at each time step from this scene information and reflects the monthly losses due to shading in the result report. Beginners can skip this step if there are no shading factors at first, but in real projects shading settings are directly linked to simulation accuracy.

The above outlines the basic setting flow explained in the PVSyst Japanese translation. By correctly setting the project location and meteorological conditions, the panel and equipment configuration, tilt and azimuth, and shading conditions, PVSyst will predict detailed annual energy production and losses for the design. Remember that the more accurate the input settings, the higher the reliability of the simulation results.

Importance of on-site survey data and the limits of manual settings

In PVSyst simulations, the accuracy of the input data determines the accuracy of the results. However, obtaining all required data accurately in practice is not easy. Here we consider the importance of on-site survey data and the limitations of traditional manual setting methods.

Input data determines simulation accuracy: As mentioned above, PVSyst allows input not only of panel layout and tilt/azimuth but also the effects of surrounding terrain, buildings, and trees. The more precise the input values, the closer the results approach reality. However, collecting such detailed data itself is often difficult. For example, to create a horizon profile considering distant mountain shadows, you would need to measure the horizon elevation at each azimuth with a compass and an inclinometer, or take and analyze all-sky images with a special camera. To understand fine undulations within and around the site, detailed topographic surveys by a surveyor or 3D mapping by drone aerial photography are required. These conventional methods take time and effort and require expensive equipment and specialized skills.

Limits of manual settings: If survey equipment is not available, designers sometimes rely on “manual settings,” estimating approximate heights from topographic maps or satellite images, or visually inspecting the site and guessing the heights of likely major shading objects. However, this approach inevitably leaves inaccuracies. Information obtained from satellite imagery or public maps has limitations in resolution and currency; for example, a building constructed a few years ago or trees that have grown may not appear in older aerial photos. Moreover, shading effects vary with date and time, so a site observation on a particular day cannot cover shading effects throughout the year. When settings are made based on incomplete data or guesses, the principle “garbage in, garbage out” applies: even if PVSyst performs precise calculations, the results will contain errors. Consequently, simulation results may deviate from actual generation due to inaccurate inputs, and even an optimized design may fail to realize expected performance.

For these reasons, obtaining high-precision on-site survey data is the key to improving simulation accuracy. If site topography can be captured to an accuracy of a few cm (a few in) and the positions and heights of surrounding obstructions can be measured accurately and reflected in PVSyst, you can estimate shading effects and irradiance losses precisely. However, “high-precision surveying” may sound like something that requires contracting a specialized survey company or using very expensive laser scanners. In recent years, solutions that make these tasks easy have emerged. One such solution is LRTK.

Using high-precision survey data with LRTK

LRTK is a cutting-edge technology for efficiently obtaining detailed on-site data. Here we explain what LRTK is, how it works, its features, and how the acquired data can be used in PVSyst design.

What is LRTK? Centimeter positioning realized with a smartphone

LRTK is the name of an ultra-compact RTK-GNSS receiver device and system that attaches to a smartphone (currently mainly iPhone/iPad). RTK stands for “Real-Time Kinematic,” a technique that enables high-precision positioning by correcting satellite positioning (such as GPS) errors in real time. Ordinary GPS has errors on the order of several meters (several ft), but with RTK you can achieve positioning with errors of a few centimeters (a few in). The LRTK device is designed so that anyone can easily use RTK positioning simply by attaching the device to a smartphone and launching a dedicated app.

The LRTK physical device is pocket-sized and lightweight, with the antenna and battery integrated. Therefore, you don’t need cumbersome wiring or large equipment; you can survey the site just by walking around with your smartphone. Usage is simple: bring the smartphone to the point you want to measure and tap a button in the app to record the moment’s latitude, longitude, and elevation with centimeter-level accuracy (half-inch accuracy). You can also attach timestamps and notes to recorded points, so naming points like “Point A southwest corner” or “Point B hilltop” makes it easier to organize data later.

Strength in offline environments: LRTK supports correction signals provided by Japan’s quasi-zenith satellite system (for example, CLAS), so a major advantage is that high-precision positioning can be maintained even in mountainous areas where mobile signals do not reach. Since PV plants are often installed in mountainous or remote areas where conventional RTK positioning struggles due to lack of mobile communication, LRTK can receive augmentation signals directly from satellites and continue positioning. This enables surveying regardless of communications infrastructure, allowing centimeter-precision surveying with just an iPhone in any location.

Efficiency and sharing: Positioning data recorded with LRTK can be uploaded to the cloud in real time. Measured points are plotted on a map on the spot, enabling immediate information sharing with remote team members. You can also calculate distances and elevation differences between any two points on site instantly, eliminating the need for tape measures or levels and manual note-taking. With one smartphone per person, multiple people can divide the work and survey large sites in a short time. Surveys that traditionally took days can be dramatically accelerated with LRTK.

Obtaining point cloud data and using it in PVSyst

LRTK’s real value is not limited to point positioning. Modern iPhones are equipped with a LiDAR scanner that can capture the surrounding environment as 3D point cloud data. LRTK’s app combines this LiDAR functionality with high-precision positioning to perform on-site 3D scanning. Simply walk around the site holding the smartphone, and the terrain and structures in view are recorded as point cloud data (a collection of many measured points). Because LRTK’s high-precision GNSS provides accurate absolute coordinates (world coordinates) to the captured point cloud from the outset, no post-scan georeferencing is required.

Traditionally, obtaining 3D point cloud data required setting up a terrestrial laser scanner on a tripod and measuring incrementally, or performing photogrammetry with a drone and creating a 3D model. Terrestrial laser scanners are expensive and require specialized operation; drone photogrammetry requires preplacing multiple known points (targets) for high precision and then correcting the dataset to those reference points. Drones also cannot capture point clouds beneath tree canopies or the backsides of buildings that are not visible from above. In contrast, iPhone scanning with LRTK allows a person to enter under obstacles or into narrow areas to measure, reducing omissions, and real-time distortion correction while walking yields a comprehensive and highly accurate 3D representation of the site.

The captured point cloud data can be uploaded to the cloud for use. On a dedicated web platform you can view it in a browser and perform necessary measurements without surveying CAD software. For example, you can compute distances, areas, and volumes between two arbitrary points with one click, or cut cross-sections to check terrain profiles. For PV plant planning, this point cloud data is extremely useful. If you generate a site topographic model from the point cloud, grading (earthwork) planning becomes more precise. By acquiring on-site topography before construction and overlaying it with planned design terrain, you can automatically calculate where and how much filling or cutting is needed (required earthwork). Earthwork calculations that once required civil engineers’ time can be greatly streamlined by leveraging LRTK data.

Improving shading analysis accuracy in PVSyst: The point cloud data acquired with LRTK also contains detailed representations of surrounding trees and structures. Analyzing these allows you to obtain high-precision information required for shading analysis in PVSyst. For example, if you scan the surrounding forest with an iPhone, you can determine each tree’s height and position within a few cm (a few in) of error. From that data you can calculate the obstruction angles relative to solar elevation (horizon profile for each azimuth or the angular heights that each tree reaches) and reflect them in PVSyst’s Near Shadings input, enabling more accurate estimation of seasonal and time-of-day generation losses. In practice, by creating a 3D terrain model from LRTK-acquired topography and point cloud data, reproducing the panel layout on it, and importing it into PVSyst, advanced analyses such as simulating when and how much each panel will be shaded over time as an animation become possible. At that point, the simulation effectively becomes a digital twin of the real site, minimizing discrepancies between simulated and actual generation after plant completion.

Improving design efficiency: LRTK contributes not only to simulation accuracy but also greatly to design process efficiency. Because high-precision survey data can be obtained in a short time, the speed of planning increases dramatically. On-site investigations that previously required ordering a survey company or obtaining drone flight permissions can now be performed by the person in charge in a short time with LRTK. There is no need to transport heavy equipment or allocate large teams; a single person can survey a wide site. Also, because LRTK data can be shared to the cloud immediately, you can discuss plans with the design team at headquarters in real time while on site, enabling faster decision-making. As a result, redundant iterations and design mistakes due to insufficient on-site verification are reduced, leading to lower costs and faster project delivery.

Conclusion: Balancing simulation accuracy and design efficiency with LRTK

PV system simulation with PVSyst delivers maximum benefit only when appropriate settings and accurate input data are provided. This article explained the basic settings for the PVSyst Japanese translation, discussed the importance of on-site data, and introduced the use of the latest surveying technology LRTK. By incorporating LRTK, you can reflect real on-site information in simulations while greatly improving design efficiency. Combine precise simulations based on high-precision on-site survey data with a smart design process to increase the success rate of PV projects.

We now live in an era where *centimeter-precision surveying with just an iPhone* is a reality, so there is no reason not to take advantage of it. Use the power of LRTK to experience reliable simulations and optimal design based on field data in your next project. Detailed feature descriptions and implementation methods for LRTK Phone are published on the official product page: https://www.lrtk.lefixea.com/lrtk-phone. If you are interested, please feel free to contact us via the inquiry form: https://www.lefixea.com/contact-lrtk. Adopt LRTK and advance your PV plant designs to the next stage with both accuracy and efficiency.