PVSyst Japanese Translation Summary: Basic Settings Guide for Beginner Designers

Introduction

PVsyst, an indispensable tool for designing photovoltaic systems, is a power production simulation software used worldwide. However, beginners using it for the first time may find the settings difficult to understand, especially since many technical terms are displayed in English. This article carefully explains the basic terms and configuration items when using PVsyst with a Japanese interface. For those looking for "PVsyst Japanese translation," we summarize the key initial setup points that beginners should know, from project creation and meteorological data input to module and inverter selection, installation angles and shading settings, and adjustment of loss parameters. By reading this article, you will understand the basic operations of PVsyst based on Japanese-language display and be able to create designs with high simulation accuracy.

What is PVsyst

PVsyst is photovoltaic simulation software developed in Switzerland. By entering meteorological data such as insolation, the specifications of solar panels (modules) and power conditioners (inverters), and installation conditions, it can calculate annual energy production, losses, and performance ratio (PR) in detail. It is highly reliable—considered a global standard—and is widely used for everything from large utility-scale projects to small residential systems. Another feature is its ability to analyze shading effects from surrounding terrain, buildings, and trees in 3D, enabling simulations that faithfully reflect site conditions. PVsyst supports multiple languages and can be switched to Japanese (change the language to Japanese in the menu settings). However, translations are sometimes incomplete, so it is important to cross-check with the English labels as you learn. In the following sections, we will go through the meanings and uses of basic settings on the Japanese interface one by one.

PVsyst Main Screen and Japanese Terminology

When you start PVsyst, a menu appears to choose the type of project and buttons to access various databases. If you select the Japanese interface, the main menus and buttons are displayed in Japanese. Below are the basic terms beginners will first encounter, presented along with their Japanese translations.

• Project Design: The mode for creating new projects and managing existing ones. Typically, choose a "Grid Connected" system.

• Site and Meteo: The screen for entering the project site’s latitude, longitude, time zone, and selecting meteorological data.

• Orientation: The settings screen to input the panel installation azimuth and tilt angle.

• System: The screen to configure system components such as selecting PV modules and inverters, the number of strings, and wiring methods.

• Simulation: The screen to run energy production simulations with the entered conditions and to output result reports.

• Near Shadings: A function to set nearby objects (buildings, trees, other rows of panels, etc.) that cast shadows on panels in a 3D model.

• Horizon: A function to define the horizon profile to account for solar obstruction by distant terrain.

These are the main menu items and their Japanese translations. Now let’s go through the specific initial setup flow and examine each item in detail.

Creating a Project and Setting Meteorological Data

First, create a project and set the site and meteorological data. From PVsyst’s main menu, select "Project Design (プロジェクト設計)" and start a "New Project." Next, choose the common system type of grid-connected (Grid Connected).

After entering the project name and notes, proceed to the Site and Meteo screen. Here you will set the following:

• Enter geographic information: Set the site’s latitude, longitude, and time zone. For locations within Japan, you can often select nearby existing data by prefecture or city name. In the Japanese UI, choose "Country" as "Japan" and then specify the prefecture or region. If the area is not listed, you can register a new site.

• Select meteorological data: Choose the meteorological data (annual insolation and temperature data) for the site. PVsyst includes typical meteorological year data for locations worldwide, but for Japanese sites users often import their own data. For example, you can import official domestic observational data from CSV or Excel into PVsyst. The Japanese interface provides a button such as "Import meteorological data," so if you have your own data, load it from there. Choosing appropriate meteorological data is a crucial step that directly affects the accuracy of energy yield predictions.

• Altitude and ground albedo: If necessary, set the site elevation (altitude) and ground reflectance (albedo). Altitude affects air density, and albedo is used to calculate additional irradiation from snow or ground reflection. For typical grassland, an albedo of about 0.2 (20%) is a common guideline.

With the site and meteorological conditions set, proceed to input the equipment information that composes the system.

Selecting Modules (Panels)

PVsyst provides a vast database of PV modules from many manufacturers, and this is available even in the Japanese interface. In the System settings screen, first select the module you will use. In the "PV module" section, choose the manufacturer and model. In the Japanese display, the manufacturer list and model numbers are usually sorted alphabetically, and most major manufacturers distributed in Japan are registered.

• Check module specifications: The selected module’s rated power (W), conversion efficiency (%), nominal operating cell temperature (NOCT), temperature coefficients, and other specs are displayed. Check these as needed.

• If the module is not registered: If the module you want is not in the database, you can add it by entering the panel specifications yourself. In the Japanese UI, use "Edit database" or "Create new module" to input parameters like open-circuit voltage (Voc), short-circuit current (Isc), and maximum power (Pm). For beginners, it’s often best to pick an existing model with similar specs and run simulations with that.

After selecting modules, move on to the power conditioner (inverter) settings.

Selecting Inverters (Power Conditioners)

Next, select the system’s inverter. These are also available from PVsyst’s database. Specify the manufacturer and model in the "Inverter" field in the system settings screen. In the Japanese display, lists are alphabetically ordered, and using a "filter by model" function makes finding the desired unit easier.

• Inverter rated capacity: The selected inverter’s rated power, input voltage range, and maximum input current are shown. Check whether the inverter capacity is appropriate for the total panel capacity (check the oversizing ratio). For example, a total panel output up to about 1.2 times the inverter rating is commonly acceptable.

• Number of units and string connections: Enter the number of inverters to use and set the number of strings (series-connected panel groups) connected to each. PVsyst shows items such as "number of strings" and "number of panels in series." The Japanese UI uses equivalent item names, where "number in series" means how many panels are connected in series per string, and "number of strings" means the number of parallel strings.

• If the model is not registered: As with modules, you can manually add an inverter if it isn’t listed. Use a "Create new inverter" button to enter rated capacity and efficiency curve. If detailed values are unknown, a beginner can substitute a similar existing model.

Once module and inverter selection and connection settings are complete, the approximate system capacity and configuration are set. The screen will display the current total capacity and expected operating voltage range—check that no errors are displayed.

Setting Panel Tilt and Azimuth

Next, set the panel installation angles. These significantly affect energy yield; specify the direction and tilt of the panels. In PVsyst’s "Orientation" screen, enter the following:

• Tilt angle (Tilt): Specify the panel tilt angle relative to the horizontal plane. In many parts of Japan, a south-facing tilt of around 30° is close to maximizing annual yield, but optimal tilt varies with latitude and project goals. In the Japanese UI, input the angle in the "Tilt" field.

• Azimuth (Azimuth): Specify the panel facing direction in degrees. In PVsyst, for projects in the Northern Hemisphere, azimuth is defined with true south as 0°. Angles towards the west are positive (e.g., west = +90°), and angles towards the east are negative (e.g., east = -90°). Thus, for south-facing in Japan enter 0°, for southwest by 30° enter +30°, and for southeast by 30° enter -30°.

• Layout options: PVsyst has layout calculation options for multiple rows (sheds), and you can choose modes such as "Unlimited sheds." For beginners, if panels of the same tilt are arranged on flat land, Unlimited sheds is convenient. In this mode, when you set the row spacing it automatically calculates the shading from adjacent rows and displays a Shading limit angle. If rows are too close so that adjacent-row shadows cover panels in winter, the limit angle will be shown as a warning—adjust spacing accordingly.

Save the settings after deciding tilt and azimuth. South-facing panels at an appropriate tilt tend to maximize annual energy, but site constraints may require compromises. For rooftop installations, measure and input the actual roof pitch and orientation.

Considering Shading (Horizon Profile and Near Objects)

Accurate photovoltaic simulation requires appropriately accounting for shading effects. PVsyst lets you set both horizon shading from distant terrain or tall structures and near-object shading from trees and buildings.

• Setting the horizon profile: If there are obstructions on the horizon (mountain ranges, hills, etc.), input their elevation angles by direction. In the Japanese UI, define the horizon by plotting obstruction heights per azimuth. For example, if there is a 5° elevation of mountains in a certain direction between east and west, set 5° for that direction. You can obtain horizon data using commercial simple apps or on-site surveys and import it as text data. A correct horizon profile reflects the impact of mountain shadows in winter mornings and evenings in the simulation.

• Setting near-object shading: Objects near the site that may cast shadows on panels—buildings, trees, utility poles, or other panel rows—can be modeled using PVsyst’s 3D shading tool. In the Japanese interface’s "Near Shadings" settings you can add objects and specify their heights and positions. For example, if a 10 m tall tree stands south of the site, add an object with height 10 m and place it at the appropriate distance using the scale. Registering multiple objects allows you to simulate time-of-day shadows throughout the year. However, overly detailed 3D modeling can increase computation load, so beginners may model only major shading sources or consider using other analysis tools as discussed below.

By setting shading, you obtain a more realistic energy prediction than calculations based solely on insolation. This is particularly useful for assessing how much generation drops during mornings, evenings, or winter, aiding risk evaluation in system design.

Setting System Loss Parameters

Finally, configure the system-specific loss items unique to photovoltaic systems. PVsyst includes default loss factors but allows customization per project. In the Japanese interface you’ll see parameters labeled "loss" or similar—review these as follows:

• Soiling loss: Loss due to dirt and dust on panel surfaces. In the Japanese UI it may appear as "Soiling loss (%)" and typically you assume a few percent per year on average. Increase this if bird droppings or sand/dust are prevalent.

• Wiring losses (cable losses): Resistive losses in DC and AC cables. Set as "% DC wiring loss" and "% AC wiring loss." For standard wiring, 1–3% each is typical; losses decrease with thicker, shorter cables. PVsyst also allows separate settings for losses between inverter and transformer.

• Temperature losses: Panels lose output as their temperature rises. PVsyst automatically calculates temperature-related losses from module temperature coefficients and ventilation conditions, and you can review this under items like "Temperature effect." Since panel temperature differs between poorly ventilated rooftops and well-ventilated ground mounts, adjust NOCT and related inputs as needed.

• Mismatch loss: Losses due to variability among panels (manufacturing tolerances) and differences in degradation rates. PVsyst lets you set a mismatch loss percentage—typically 1–2% by default.

• Other losses: Conversion loss (calculated via inverter efficiency), transformer losses (for large systems), downtime due to nighttime self-consumption or maintenance, and so on can also be considered. Detailed settings like "Transformer loss" and "System stop periods" are available in PVsyst’s advanced settings. For beginners, default values are usually acceptable, but adjusting these to reflect actual conditions improves accuracy.

These loss settings determine how much the ideal generation is reduced in the simulation. The result reports break down losses so you can see which items contribute most to energy reduction.

Improving Design Accuracy by Using LRTK Terrain and Obstruction Data

So far we’ve explained PVsyst’s basic initial settings based on the Japanese interface. Finally, as a way to further improve simulation accuracy, we touch on how to incorporate detailed on-site terrain and obstruction data. Recently, beginners have increasingly used simple surveying tools to obtain 3D site data and reflect it in PVsyst. A representative solution is using LRTK.

With LRTK, you can perform easy measurements with a smartphone to obtain boundary coordinates, terrain elevation differences, and the positions and heights of surrounding structures and trees with high precision (centimeter-level). Using the acquired coordinates and point cloud data, you can enhance PVsyst settings in the following ways:

• Apply to the horizon profile: Calculate elevation angles of distant mountains or high ground from the terrain data measured with LRTK and enter these directly in the "Horizon" definition. This ensures terrain-based solar obstruction is fully reflected.

• 3D modeling of near objects: LRTK point cloud data includes details of nearby trees, poles, and buildings. From this you can determine object heights and positions and place equivalent objects in PVsyst’s near-shading settings. Alternatively, importing a 3D model created from point cloud data into PVsyst allows analysis of shading at the level of individual panels.

• Reflect terrain undulation: For large sites with elevation changes, generate a surface model from LRTK survey data and reflect it in the panel layout on PVsyst. For example, adjust racking heights to follow sloped land or compare pre- and post-development terrain to study impacts on energy production—such advanced analyses are possible when actual measurement data are available.

By leveraging simple survey data from LRTK, you can dramatically improve the input accuracy for PVsyst simulations. Terrain and shading information that previously required specialized survey equipment or complex methods can now be obtained easily by beginners with LRTK. As a result, you can minimize the gap between simulation and reality and achieve more reliable energy predictions and optimized designs. Even those new to solar design can achieve near-professional accuracy in planning by combining PVsyst basics with technologies like LRTK. Using this PVsyst Japanese-interface basic settings guide, try conducting high-accuracy simulations for your projects.