How to Read the PVSyst Interface | Clarifying 8 Points That Confuse Beginners

Table of Contents

• View the PVSyst screens in sequence from project creation to results review

• On the main screen, check the analysis level and the work menu

• In the project screen, organize the project information and site conditions

• In the meteorological data screen, confirm the location and the data types

• In the system screen, view the combination of panels and PCS

• In the layout screen, check the orientation, tilt, and placement conditions

• In the shading settings screen, check surrounding obstacles and the shading calculation conditions

• In the losses settings screen, reflect site conditions as numerical values

• In the results screen, read the annual energy production and the loss breakdown

• Procedure to verify PVSyst screens for practical use

View the PVSyst screens in the workflow from project creation through result confirmation

When trying to understand the PVSyst interface, what matters is not memorizing individual buttons or input fields, but first grasping the overall workflow. PVSyst is software for entering the design conditions of a photovoltaic system, calculating energy production based on meteorological data and equipment specifications, and evaluating those results. Therefore, the interface is basically organized in the order of creating a project, setting conditions, running the simulation, and reviewing the results.

The reason beginners often get confused is that so many settings are displayed on the screen. When you first see it, you may feel you cannot proceed unless you enter everything accurately. However, in practice, rather than trying to perfect detailed loss values or shading conditions from the start, the common approach is to first create a rough estimate based on basic conditions and then refine its accuracy by incorporating site and design conditions.

PVSyst's screens are to be used according to the maturity of the design. In initial studies, the focus is on checking the installation site, system capacity, panel surface tilt, orientation, and the general equipment configuration. In detailed design, you examine string configuration, PCS capacity, temperature losses, wiring losses, shading effects, downtime, soiling, and degradation over time. In the stage approaching completion, verify that the numerical values in the result report are consistent with the design conditions and that no unexpected losses or warnings are present.

When viewing the screens, it is easier to understand if you first check the overall project information, then proceed in the order of meteorological data, equipment configuration, layout, shading, losses, and results. Although each screen may appear to be independent, they are actually all connected. If the meteorological data changes, the power generation changes; if the panel tilt or azimuth changes, the way solar irradiance is received changes. If the PCS capacity changes, the amount of output curtailment changes, and if the shading or soiling conditions change, the breakdown of losses changes.

To get used to the screens, it’s important to be aware of "what this screen determines," "which part of the results this input affects," and "whether the item can be modified later." PVSyst has many input fields, so beginners tend to focus on the details, but by first grasping the overall flow you can greatly reduce hesitation during operation.

On the main screen, confirm the analysis level and task menu.

The main screen you first see when you launch PVSyst is the gateway to your work. From here you decide what type of analysis to perform, whether to open an existing project, create a new project, or which settings area to enter. For beginners, choosing which menu to select on this main screen is the first point of confusion.

On the main screen, it's easier to understand if you first separate whether the task you want to perform is "create a new project", "edit an existing project", or "review results". If you are beginning to evaluate a new power plant, create a new project and proceed to set the location and meteorological conditions. If you need to modify a project that has already been created, open the existing project and change the relevant conditions. If you want to check results from a past run, open the simulation results or report screen.

What to note on the main screen is that you can handle multiple design proposals within the same project. For example, you might compare proposals that change the tilt angle on the same site, proposals that change panel capacity, proposals that change PCS capacity, or proposals that change shading conditions. In this case, you need to be aware of the relationship between the project and the design proposals on the screen. It is easier to understand if you think of the project as representing the entire case, and the design proposal as representing a pattern of conditions within it.

What often confuses beginners is that multiple options are displayed before entering the settings screen. It can appear that any choice will lead to a similar screen, but in practice the screen you should use changes depending on whether you want to check annual power generation, finalize the equipment configuration, or examine the effects of shading. If your primary aim is a power generation simulation, start by focusing on screens intended for a standard grid-connected generation system rather than those for detailed research or specialized analyses.

On the main screen, you don't need to try to use every feature right away. In practical work for power generation calculations, the common workflow is project creation, meteorological data settings, system settings, layout settings, shading settings, loss settings, running the simulation, and checking the results. If you can use this sequence of screens, you'll have a solid understanding of the basic use of PVSyst.

When you open a screen, it's a good habit to check which level you are currently in. If you can distinguish whether you're on the overall project screen, a design-proposal screen, or an individual-condition screen, you will be less likely to mistake where input values are saved or the scope to which results are applied. Especially when comparing multiple proposals, editing without confirming which proposal is open can lead to unintended changes to the conditions.

On the project screen, organize project information and site conditions

The Project screen is the interface in PVSyst for managing a project's basic information. Here you confirm the power plant's location, latitude and longitude, elevation, time zone, association with meteorological data, project name, design scenario name, and other details. Because energy production simulations are heavily influenced by the installation site's conditions, the Project screen is not merely a place to enter a name but an important screen for defining the assumptions for the calculations.

Beginners should first verify that the project's location is set correctly. Solar power generation is affected by local solar irradiance, temperature, solar elevation, and seasonal variations. Even with the same installed capacity, the annual output will change depending on the installation site. Therefore, if the latitude/longitude or site information is incorrect, subsequent calculation results will also deviate from reality.

On the project screen, it's important not to judge based only on addresses or place names but to also check numerical parameters such as latitude, longitude, and elevation. Especially in mountainous areas, developed sites, or large power plant sites, elevation and the appearance of the surrounding terrain can change depending on where the representative point is placed. In initial assessments it is common to use a representative point at the center of the site, but in detailed studies it may be better to verify locations with the actual array layout area in mind.

Project names and design proposal names are also important in practice. If you simply manage them with names like "New Project" or "Plan 1", it's easy to become confused later when comparing conditions. When handling multiple proposals on the screen, it is easier to manage them if you give names that indicate differences such as tilt angle, capacity, PCS ratio, shaded/unshaded, and loss conditions. When you're not yet familiar with how to read PVSyst screens, it's often hard to tell which proposal is the latest, so simply deciding on a naming convention can reduce mistakes.

In the project screen, be aware that location settings and meteorological data are separate concepts. Entering the installation site alone does not necessarily mean appropriate meteorological data has been assigned. Location information indicates the project's position, while meteorological data refers to the time-series or monthly data used in calculations, such as solar radiation and temperature. Verifying that these two are consistent for nearby points is the first step toward an accurate simulation.

Also, the project screen affects all subsequent screens. If the location changes, the sun’s path, solar irradiation conditions, temperature conditions, and the appearance of shadow effects will also change. Therefore, before entering the system settings or loss settings, it is important to first finalize the project’s basic conditions on the project screen. If you change the location conditions later, you will need to re-evaluate the results you have already reviewed.

On the weather data screen, confirm the location and data type

The meteorological data screen is a crucial screen for PVSyst’s energy production calculations. Here you select or create the meteorological conditions that affect energy production at the site—such as solar irradiance, air temperature, and wind speed. Beginners tend to focus on equipment capacity and panel settings, but in reality the choice of meteorological data can greatly change the results for annual energy production.

On the meteorological data screen, the first thing to check is whether the data location matches the project’s installation site. Even when using data from a nearby representative point, solar radiation and temperature trends can vary depending on distance, elevation, topography, whether the site is coastal or inland, and whether it is mountainous or on a plain. Rather than simply choosing the nearest point, it is important to consider whether the data are representative of the power plant’s environment.

The next thing to check is the type of meteorological data. Using monthly average data makes input and comparison simple, but it can be difficult to reflect hourly variations and temporary shading effects in detail. Conversely, using hourly data is better suited to more detailed simulations, but it is important to check the data quality and the period covered. In practice, readily available representative data are used in the early stages, and for detailed analysis they are switched to data whose accuracy and justification have been verified.

On the meteorological data screen, attention also needs to be paid to the types of solar irradiance. In photovoltaic power generation there are multiple concepts, such as horizontal plane irradiance, direct irradiance, diffuse irradiance, and tilted plane irradiance. PVSyst calculates the irradiance incident on the panel surface based on the input meteorological data. Therefore, understanding which type of data is included and whether any conversion or gap‑filling has been performed makes it easier to interpret the results.

What beginners often overlook is that after selecting meteorological data they fail to check the trends in the graphs and monthly values. Instead of looking only at annual power generation, it is important to confirm whether the month-by-month changes in solar irradiance and temperature follow natural patterns. For example, check that the summer and winter trends are not extremely unnatural, that temperatures do not deviate greatly from the local climate, and that solar irradiance is not excessively high or low.

The weather data screen is important when explaining results later. If you are asked for the basis of the energy yield and cannot explain which location's data you used, the credibility of the simulation results will suffer. To use PVSyst's screens effectively, you should not treat meteorological data as mere selectable items, but verify them as the assumptions for the energy yield calculation.

On the system screen, you can view the combination of panels and PCS

The System screen is one of the PVSyst screens that practitioners check most frequently. Here you configure the type of solar panels, the number of panels, the string configuration, the PCS capacity, input circuits, the voltage range, and the relationship between DC capacity and AC capacity. This screen is used to determine whether the power generation installation is viable, and it affects not only the annual energy production but also the validity of the design.

What beginners should first look at is the relationship between the DC-side capacity and the AC-side capacity. In photovoltaic power generation, the panel capacity and the PCS capacity are not necessarily exactly the same. Some designs make the panel capacity larger than the PCS capacity, and in such cases output limitation (clipping) can occur during periods of high irradiance. The system screen in PVSyst lets you check the effects of such capacity ratios and output limitations.

Another important point is the electrical compatibility between the panels and the PCS. Confirm that the number of modules in series per string, the number in parallel, the input voltage, the maximum current, and any voltage increases or decreases due to temperature changes fall within the equipment's allowable range. If warnings or cautions appear on the screen, do not dismiss them as mere indicators; you must check which condition is out of range.

On the system screen, it is important not only to select the panel model and PCS specifications but also to be mindful of the actual wiring configuration. For example, even with the same number of panels, the voltage and current change depending on how they are arranged in series and parallel. In designs with little margin in the voltage range, the open-circuit voltage at low temperatures or the operating voltage at high temperatures can become problematic. In PVSyst’s interface, you adjust the configuration while checking these ranges.

What beginners often get confused about is the order in which to enter numbers into the input fields. Trying to input a perfect, detailed string configuration from the start can feel difficult. It's easier to understand if you work in this order: first decide an approximate system capacity, set the number of panels, choose the PCS capacity, and then refine the string configuration. Even if you want to quickly check an estimate of generation, it's safer not to use results that show electrical warnings as they are.

Also, the System screen is related to the Layout screen. Even if you set the electrical configuration on the screen, that number of panels may not be placeable on the actual site. Conversely, even if placement is possible on the Layout, the electrical string configuration may not be feasible. Therefore, when using PVSyst it is important to go back and forth between the System and Layout screens to reconcile capacity and placement.

On the layout screen, view orientation, slope, and placement conditions

In the layout screen, you check the orientation, tilt, and placement of the solar panels. In PVSyst’s energy production calculations, the irradiance on the panel surface is important, and that irradiance is strongly influenced by azimuth and tilt. Therefore, the layout screen should be understood not merely as a view for seeing the layout, but as the screen that determines the generation characteristics.

The first thing a beginner should check is the orientation (azimuth) setting. Which way the panels face affects morning and afternoon generation patterns, the annual amount of solar radiation received, and seasonal power output. When entering the azimuth angle, misunderstanding the reference direction or the sign convention can result in the panels being set to a direction different from the intended one. It's important to verify not only the on-screen display but also the numeric value to confirm which direction the panels are pointing.

Next to consider is the tilt angle. The tilt angle affects annual energy yield, winter solar gain, summer generation characteristics, and the impacts of snow and soiling. With a low tilt it is easier to increase installation density, but you need to account for shading effects and how soiling persists. A higher tilt can be advantageous for winter solar gain, but it must be balanced against wind loads, row spacing, and the number of modules that can be installed.

In the layout screen, the spacing between panels is also important. If the spacing between rows is narrow, the duration that shadows from the front row fall on the rear row increases. Especially during winter and at sunrise and sunset when the sun’s altitude is low, inter-row shading affects power generation. In PVSyst, because layout conditions are used to drive shading and solar irradiance calculations, the settings in the layout screen also affect the shading settings and results screens.

What beginners often overlook is that the visual layout and the calculation conditions do not necessarily mean the same thing. Even if panels appear to be arranged on the screen, if the orientation, tilt, spacing, or shadow treatment used in the calculations are not set correctly, the results will not reflect the intended conditions. Rather than being reassured by the layout diagram, it is important to check the numerical settings and calculation conditions.

Also, in practice it is necessary to cross-check the on-site survey results, site development plans, ground slope, and racking layout plans. The layout in PVSyst is a model for energy yield calculations and is not a construction drawing itself. It is important to identify which aspects can be reflected in PVSyst while separately considering site elevation differences, boundaries, access/maintenance paths, clearances, slopes, drainage facilities, and so on.

On the shadow settings screen, view surrounding obstacles and shadow calculation conditions

The shading settings screen is one of the screens in PVSyst that beginners find particularly confusing. In solar power generation, shading is caused by surrounding buildings, trees, mountains, rows of mounting racks, and site equipment. Shading not only reduces power output, but its impact varies with the time of day and season, so you need to decide how much detail to enter.

On the shadow settings screen, the first thing to consider is what is causing the shadow. Whether the shadow is due to distant terrain, nearby buildings, or shadows between rows of panels will change which settings you need to check. Shadows from distant mountains or the horizon can affect conditions during times when the sun is low. Shadows from nearby obstacles can cast partial shading on specific arrays or strings. Inter-row shading is closely related to spacing and tilt angle.

A common mistake beginners make is thinking that adding shadow settings will always improve accuracy. In practice, if the shadow model does not match the site conditions, it can actually make the results harder to interpret. A realistic, staged approach is to grasp the rough effects of shadows in preliminary assessments, and in detailed studies reflect the positions and heights of obstacles based on on-site surveys and drawing information.

On the shadow settings screen, check the height, distance, azimuth, and shape of obstacles. Even when representing buildings or trees with simple shapes, the positional relationship to the power generation equipment is important. Obstacles close to the panel surface, in particular, can change how shadows fall with only slight shifts in position. Because site photos and plan views alone can lack information in the vertical direction, it is advisable to verify with on-site surveys or three-dimensional data when possible.

Shadows have both an effect as a loss of solar irradiance and an effect as electrical mismatch. If part of a panel surface is shaded, it can affect not only that area but the output of the entire circuit. In the PVSyst interface, it is important to check how shadows are calculated and to what extent electrical effects are considered. The interpretation of the results changes depending on whether you are looking only at simple irradiance losses or at impacts that account for the string configuration.

When using the shadow settings screen, you need to check it together with the loss breakdown on the results screen. After setting shadows, verify how much the annual energy production has changed, which months are most affected by shadows, and whether the losses are larger than expected. If the shadow impact is significant, consider revising the layout, adjusting row spacing, changing the orientation of the panel surface, and maintaining clearance from obstacles.

Reflect site conditions as numerical values on the loss settings screen

On the loss settings screen, you configure how much the power generation system loses compared to the ideal state. This screen in PVSyst is one where the judgment of the practitioner is strongly reflected. You enter numerical values for various conditions according to the site and design, such as temperature loss, wiring loss, soiling, mismatch, equipment loss, downtime, and degradation over time.

A difficulty for beginners is that there are many loss items and their meanings can look similar. However, loss settings are an important part of determining the plausibility of the power generation estimate. For example, when a panel’s temperature rises, its output decreases. If wiring is longer, losses due to electrical resistance increase. If the panel surface is dirty, the transmission of solar irradiance is reduced. If part of the equipment is offline, generation during that period decreases. The annual energy production result changes depending on how much you allow for these losses.

When viewing the loss settings screen, it is important to first check whether it is acceptable to use the default values as they are. The default values serve as a starting point for the calculations, but they are not necessarily optimal for every project. In areas with a lot of sand and dust, areas with snowfall, coastal areas prone to salt exposure, rooftops that tend to reach high temperatures, and large-scale installations that require long-distance wiring, the loss conditions should be reviewed and adjusted to fit the site.

Temperature losses are influenced by how the panels are installed and by ventilation conditions. The way panel temperature rises differs between ground-mounted installations with good airflow and installations mounted close to the roof surface. On the screen, check the temperature-related coefficients and conditions and verify that they match the actual equipment. Because temperature losses affect power generation year-round, they cannot be overlooked.

Wiring losses are influenced by the wiring lengths on both the DC and AC sides, as well as current, voltage, cable conditions, and other factors. In preliminary studies, approximate values may be used, but in detailed design it is necessary to verify them against the actual layout and collector system plan. In large-scale power plants where wiring distances become long, the expected wiring losses affect the assessment of energy production.

Settings for soiling and downtime also vary depending on site conditions and operational policies. If there are conditions such as a lot of airborne dust nearby, proximity to farmland or unpaved roads, expected bird damage, low cleaning frequency, or long maintenance response times, consider whether to reflect them in the loss settings. On the PVSyst screen you simply enter numbers, but behind that is a judgment about how to view the actual situation at the site.

When using the loss settings screen, it's not correct to simply set all losses conservatively high. Entering excessively large losses will cause you to underestimate the power output more than necessary. Conversely, setting losses too low will lead to large deviations from the plan during actual operation. The important thing is to use values that have a solid basis and can be explained afterward.

On the results screen, read the annual power generation and the breakdown of losses

The results screen is where you can check how the conditions set in PVSyst are reflected in the energy production. When you run the simulation, annual energy production, monthly energy production, specific yield, performance indicators, loss breakdown, and so on are displayed. Beginners tend to look only at the annual energy production figure, but in practice it is important to read how that figure was derived.

The first thing to check is the annual energy generation. This is a basic metric that indicates how much electrical energy an installation will generate over a year. However, annual generation increases with installed capacity, so a simple comparison of absolute values alone cannot determine the quality of a design. Checking generation per unit of capacity and indicators similar to capacity utilization together makes it easier to compare design proposals.

Next to check are the monthly generation trends. In solar power generation, the amount of solar irradiance and temperature change with the seasons, so generation also varies month to month. By checking monthly trends on the results screen, you can judge whether the effects of weather data, orientation, tilt, and shading are being naturally reflected. For example, if generation is extremely low in only a specific month, it can prompt a review of shading, weather data, or loss settings.

Loss breakdown is also important. On PVSyst's results screen, you can check, step by step, the factors that reduce energy production—such as irradiation conversion, temperature, shading, wiring, equipment, mismatch, and output limitation. By looking at this loss breakdown, you can understand which factors have the greatest impact on energy production. Simply looking at the final energy production figure alone does not tell you where there is room for improvement.

What beginners should pay particular attention to is whether there are losses larger than expected. For example, if shading losses are too large, you need to review the layout and obstacle settings. If output limitations are large, you need to reconsider the relationship between panel capacity and PCS capacity. If temperature losses are large, check the installation method and ventilation condition settings. If wiring losses are large, review the wiring length and electrical design conditions.

On the results screen, also check for warnings and caution messages. Even if the calculation itself has completed, there may be inconsistencies or caveats in the input conditions. If you use a report that shows warnings as-is, you may find it difficult to explain later. It is important to review the warning contents and determine whether they indicate a design problem, an input mistake, or that the conditions should be reassessed.

Also, if you use the results report for external explanations, you need to confirm the underlying assumptions. If you extract and share only the annual energy production figure, it becomes unclear which meteorological data were used, what losses were assumed, whether shading was considered, or under what conditions the system capacity was defined. The PVSyst results screens should be viewed not merely as an answer display but as explanatory material that connects design conditions and calculation results.

Verification Procedures to Master PVSyst Screens for Practical Use

To master using PVSyst's interface in practical work, it is important to understand the role of each screen and to have the same verification procedure each time. Beginners tend to open and edit screens as they occur to them, but that approach makes input omissions and inconsistencies in conditions more likely. Standardizing the verification flow for each project stabilizes work quality.

First, on the project screen verify the project name, installation location, latitude and longitude, elevation, and design plan name. If the site conditions are off here, subsequent meteorological data and solar radiation calculations will also be off. Next, on the meteorological data screen confirm the location, period, type, and monthly trends of the data to be used. Because meteorological conditions form the basis for power generation estimates, it is important not to proceed while these remain ambiguous.

After that, on the system screen, check panel capacity, PCS capacity, string configuration, voltage range, and whether any warnings are present. After confirming that the installation is viable as equipment, proceed to the layout screen and check orientation, tilt, layout spacing, and the number of panels that can be installed. Here, be mindful of whether the electrically viable configuration also fits the actual site conditions.

Next, check the conditions for obstacles and inter-row shading on the shadow settings screen. When adding shadows in detail, consistency with on-site information and survey data is important. If the shadow input is uncertain, you can compare cases with and without shadows to understand the magnitude of the impact. Then proceed to the loss settings screen and verify that values for temperature, wiring, soiling, downtime, mismatch, and other factors match the site conditions.

Finally, run the simulation and check the annual generation, monthly generation, loss breakdown, and any warning messages on the results screen. If the results differ from expectations, it is important not to immediately correct only the numbers, but to trace which screen's conditions are causing the discrepancy. If generation is too low, check the meteorological data, shading, temperature, output limits, and wiring losses in that order. If generation is too high, check whether any losses were omitted, shading was not reflected, or the equipment capacity was set incorrectly.

An important point when interpreting PVSyst screens is not to look at each screen in isolation. The project, meteorological data, system, layout, shading, losses, and results are all interconnected. Changing a single value will affect the results on other screens. By keeping those relationships in mind when reviewing the screens, your use of PVSyst shifts from mere operation to a tool for design analysis.

Also, in practice it is important not only to enter data into PVSyst but also to accurately grasp the on-site conditions. The power plant site contains many pieces of information that affect energy yield and layout—such as elevation differences, slopes, boundaries, existing structures, trees, access paths, drainage facilities, and the surrounding terrain. If these cannot be accurately identified, no matter how carefully PVSyst is configured, discrepancies with the actual site will remain.

Particularly for shadow settings and layout evaluations, on-site location and elevation information becomes important. Even if plans appear fine on drawings, the way shadows fall can actually change due to the heights of surrounding features and variations in ground surface. If you can streamline site positioning and terrain verification, it becomes easier to improve the reliability of the conditions entered into PVSyst.

Therefore, in practical work conducting power generation simulations with PVSyst, it is important to treat desktop configuration tasks and on-site measurements as an integrated process rather than separate activities. By identifying the site's coordinates, elevation, planned equipment locations, and obstacle positions and reflecting them in the design conditions, you enhance the explanatory power of the simulation results. The ability to correctly interpret PVSyst's screens is not only about understanding the input screens, but also about judging which fields should reflect the site information.

If you want to streamline the acquisition of site conditions, using LRTK (iPhone-mounted GNSS high-precision positioning device) makes it easier to apply the highly accurate location information obtained on site to design considerations. In planning photovoltaic installations, it is important to be able to quickly confirm on-site information such as site boundaries, planned racking locations, surrounding obstructions, ground elevation, access/maintenance paths, and slopes. By correctly setting the conditions on-screen in PVSyst and accurately capturing on-site location information with LRTK, it becomes easier to link power generation simulations with actual construction planning.