How to Configure Panels in PVSyst｜A 6-Step Guide from Model Selection

Table of Contents

• Why panel settings are important in PVSyst

• Information to organize before configuring panels

• Step 1: Check the specifications of candidate photovoltaic modules

• Step 2: Select the model from PVSyst's module database

• Step 3: If the corresponding model is not available, use a close specification or register a new one

• Step 4: Match the number of panels, series count, and parallel count to the system conditions

• Step 5: Check temperature characteristics and loss conditions

• Step 6: Review configuration errors based on simulation results

• Common mistakes and countermeasures in panel configuration

• Handling on-site information to improve accuracy in practice

• Summary

Why panel settings are important in PVSyst

In PVSyst, configuring the panels is a crucial step when simulating the power output of a photovoltaic installation. Many factors affect generation — weather data, azimuth, tilt angle, shading, losses, wiring conditions — but at the center is the photovoltaic module configuration. Which panel model to use, how many panels to install, and how to arrange them in series and parallel will change the system’s overall capacity, voltage, current, temperature-related output variations, and the projected annual energy production.

Many practitioners researching how to use PVSyst are not only interested in learning the screen operations but also want to know how to enter design conditions so that the results are valid. For example, even if you set values based only on a panel’s nominal power, if the temperature coefficient, open-circuit voltage, short-circuit current, or maximum power point voltage differ from the actual module type, the simulation results will also be off. In particular, as the size of a power plant increases, small differences in inputs can have a large impact on annual energy yield and loss assessments.

Also in PVSyst, not only the performance of individual panels but also their combination with the power conditioner is important. Even if the number of panels is appropriate, too many in series can lead to overvoltage at low temperatures. Conversely, too few in series can make it difficult to enter the operating voltage range, causing reduced efficiency and lost generation opportunities. In other words, panel configuration is not merely a model selection but a fundamental task to verify the feasibility of the entire power generation installation.

This article explains how to set up panels in PVSyst in 6 steps, from selecting the model to verifying the system configuration. To make the practical workflow easy for beginners to understand, we outline the items to check during data entry, how to approach cases when a model cannot be found, and verification methods to prevent configuration mistakes.

Information to prepare before configuring panel settings

Before setting up panels in PVSyst, it is important to first organize the design conditions. If you open the interface and start looking for input values, there are many similar items and it is easy to become unsure which numbers to use. In actual practice, because you work while referring to multiple documents—design drawings, equipment specifications, layout plans, grid interconnection requirements, and on-site survey results—whether you prepare beforehand directly affects work efficiency.

The first piece of information to confirm is the model of the photovoltaic module you plan to use. If the model has been decided, check the datasheet for rated output, dimensions, open-circuit voltage, short-circuit current, voltage at maximum power (Vmp), current at maximum power (Imp), temperature coefficients, and so on. If the model has not yet been decided, organize the candidate power ranges, module dimensions, available installation area, and the expected generation capacity. In PVSyst you can also select a similar model from the database, but for the final assessment it is important to input conditions that are close to the module that will actually be adopted.

Next, confirm the number of panels to be installed and the layout conditions. On rooftops, ground-mounted, sloped terrain, racking installations, etc., the number of panels and the row spacing will vary depending on site conditions. You need to determine the actual number that can be installed by taking into account panel dimensions, aisle widths, maintenance space, clearance distances, and shading effects. Rather than deciding system capacity solely from PVSyst panel settings, it is important to align it with the layout plan.

Additionally, organize the combination requirements with the power conditioner. Check the input voltage range, maximum input voltage, maximum input current, number of circuits, capacity ratio, etc., and verify whether the number of panels in series and in parallel is feasible. In PVSyst, warnings about the combination of panels and the power conditioner may appear in the system settings. To correctly judge these warnings, you need to understand the equipment specifications in advance.

Finally, don’t forget site conditions. Temperature, ventilation, snowfall, salt damage, shading from nearby structures, terrain undulation, and variations in orientation and tilt all affect a panel’s effective output and losses. In PVSyst panel settings, you are required not only to enter the module specifications correctly but also to appropriately account for temperature losses, mismatch, and shading effects according to the site conditions.

Step 1: Confirm the specifications of candidate solar cell modules

The first step is to check the specifications of the candidate PV modules. Before selecting a model in PVSyst, reviewing the basic items listed in the datasheet will make it easier to determine whether the information in the database is correct or whether it can be used as an approximate model.

What's particularly important is not just the nominal maximum output. Check the maximum power operating voltage, maximum power operating current, open-circuit voltage, short-circuit current, power temperature coefficient, voltage temperature coefficient, and current temperature coefficient. These values affect not only the energy yield but also the feasibility of the string configuration. For example, because module voltage rises in cold conditions, you need to verify—based on the open-circuit voltage and temperature coefficient—that the maximum input voltage will not be exceeded. Conversely, because voltage falls at high temperatures, you should also check that the operating voltage does not drop below the lower limit of the operating range.

Panel dimensions are also important. While PVSyst simulations themselves focus mainly on electrical evaluation, dimensions are relevant for 3D scenes, shading assessments, and the examination of installation area. If the actual layout plan and the number of panels do not match, even if the entered generation capacity is correct, shading evaluations and considerations of row spacing can become inaccurate. Especially for ground-mounted systems, shading patterns change depending on whether panels are installed landscape or portrait, the tilt angle, row spacing, and the slope of the terrain, so it is important to accurately understand the dimensional information.

Also, when dealing with bifacial modules, consider how to evaluate the contribution from the rear side. The contribution to energy yield varies depending on reflectivity (albedo), mounting height, ground surface condition, row spacing, rear-side shading, and so on. PVSyst may allow settings for bifacial reception, but if you set input values too optimistically, the estimated energy yield can be more optimistic than reality. During the design phase, it is important to adopt conservative values that match local conditions.

One point to watch when checking specifications is that electrical characteristics can differ by model even within the same output range. For example, panels with the same nominal output may have models with higher voltage and models with higher current. Because compatibility with the power conditioner is affected by these differences, it is safer to avoid substituting based solely on the output rating. Even if you cannot find the model in PVSyst, choosing a model with similar voltage, current, and temperature coefficients will lead to a more realistic simulation.

Step 2: Select the module model from PVSyst's module database

After reviewing the specification sheet, the next step is to select the corresponding model from PVSyst's module database. PVSyst contains a large number of photovoltaic module records, and you can search by manufacturer name, model, power output, technology type, and so on. In practice, whether you can select the correct model here will determine the accuracy of the subsequent system settings.

When searching for a model number, start with the official model name listed in the specification sheet. However, the notation in the database may differ slightly. The presence or absence of hyphens, how output values are written, generation differences, or differences in trailing symbols can cause a model not to appear in search results. Therefore, if you cannot find an exact match, it is effective to search by part of the output value or part of the model number to narrow down the candidates.

Even if the corresponding model is found, cross-check the values with the specification sheet before using it as is. Confirm that the rated maximum power, open-circuit voltage, short-circuit current, maximum power operating voltage, maximum power operating current, and temperature coefficient do not differ significantly from the specification. Database entries are convenient, but differences in model generations or specification updates can cause them to disagree with your on-hand documents; especially when used for energy yield estimates or design studies, the standard practice is to use the specification sheet planned for adoption as the reference.

In the module database, you also check cell technology and module characteristic models. Differences such as monocrystalline, polycrystalline, and thin-film affect temperature characteristics and behavior under low irradiance. In current practice, monocrystalline types are often adopted, but past projects or special conditions may involve different types. When simulating in PVSyst, it is important to select a model that closely matches the actual module characteristics.

After selecting from the database, it is reflected in the project's system settings. At this stage, it will be verified in conjunction with the selection of the power conditioner and the string configuration. PVSyst calculates the number of modules in series, the number in parallel, the capacity ratio, the voltage range, and other parameters based on the selected panel model. Therefore, if the module model chosen initially is incorrect, subsequent design decisions will also be off.

Step 3: If there is no matching model, handle it with a similar specification or by registering a new one

In practice, the PV module you plan to use may not be found in PVSyst's database. This can happen when it’s a new model, a model for a specific market, a model with different specifications, or simply a difference in how it’s listed. In such cases, rather than hastily choosing a different model, you should decide whether to handle it by using an approximate equivalent or by registering it as a new model.

When using models with similar specifications, select ones that are close not only in nominal maximum output but also in voltage, current, and temperature characteristics. Even if only the output value is the same, a large difference in voltage will affect the evaluation of the string configuration. For example, if the maximum power operating voltage differs, the input voltage will change even with the same number of modules in series. If the open-circuit voltage differs, it will also affect the determination of the maximum voltage at low temperatures. Differences in short-circuit current or maximum power operating current are also related to considerations of input current and the number of parallel circuits.

When registering a new device, enter the numerical values from the specification sheet carefully. PVSyst allows you to manually register a module's electrical characteristics, so you can create a model close to the actual specifications even if there is no model designation. However, because there are many input fields, you must be careful not to mix up units or conditions. Enter values while confirming whether they are values under standard test conditions, whether the temperature coefficients are expressed as percentages, and whether they are voltage coefficients or current coefficients.

When registering a new module, pay particular attention to the representative values and tolerances listed on the datasheet. Solar PV modules have output tolerances and measurement conditions, and actual products exhibit variability. In PVSyst you enter them as a standard model, but you should not treat the simulation results as overly precise numbers; instead, evaluate them together with the design conditions and loss settings.

Also, when multiple people within the company or project use PVSyst, managing newly registered module data is important. If different staff register different values, simulation results can vary even for the same project. Organize the model identifier, registration date, the specification documents referenced, and the rationale for the input values, and manage them in a reusable format so that checks in later stages proceed smoothly.

Whether you use an approximate model or register a new system, it is important that you can explain why you chose those settings. In materials used for generation forecasts, design capacity, loss assessments, and investment decisions, the appropriateness of input assumptions may be scrutinized. When using PVSyst, consider not only the on‑screen operations but also documenting the rationale for settings as part of professional-quality work.

Step 4: Match the number of panels, series connections, and parallel connections to the system requirements

Once you set the panel model, next adjust the number of panels, the number of modules in series, and the number of parallel strings to match the system conditions. This is one of the parts of PVSyst’s panel settings that is prone to mistakes in practice. Even if you enter only the number of panels to match the generation capacity, if the series and parallel counts are not appropriate, the configuration may not be electrically viable.

First, confirm the total number of installed modules. Check whether the number in the layout plan matches the number in PVSyst. For ground-mounted installations, the number of modules may differ by plot. For rooftop installations, the azimuth and tilt may vary by roof surface. In such cases, decide whether it is acceptable to aggregate everything under a single condition or whether they should be separated into subarrays. Treating panels with substantially different azimuths or tilts as a single condition can lead to a coarse assessment of energy yield and losses.

Next, set the number of panels in series. The number of panels in series indicates how many panels are connected in series. Increasing the number of panels in series raises the voltage, while decreasing it lowers the voltage. Verify that the open-circuit voltage at low temperatures does not exceed the power conditioner's maximum input voltage, and that the maximum operating voltage at high temperatures does not fall below the operating range. PVSyst may display warnings for these conditions. If a warning appears, do not simply ignore it; review the temperature conditions, the number of panels in series, and the equipment specifications.

The number of parallel strings indicates how many identical series strings are connected in parallel. Increasing the number of parallels increases the current. Configure it while paying attention to the input current limit and any constraints on the number of circuits. When using high-power, high-current modules in particular, the current requirements can become more stringent. You must check not only the number of series strings but also the compatibility between the parallel count and the input current.

We also check the ratio between panel capacity and power conditioner capacity. In solar power systems, designs in which the panel capacity is larger than the power conditioner capacity are commonly considered; however, if that ratio is too high, output curtailment and clipping losses may increase. Conversely, if it is too low, it can be inefficient from the perspective of equipment utilization. In PVSyst, clipping losses and system losses can be checked from the simulation results, so always review the results after configuring the settings.

In this procedure, consistency with the design drawings and the single-line wiring diagrams is indispensable. Even if it appears to be valid in PVSyst, it may differ from the actual wiring plan and the junction box configuration. When determining input values, cross-check the electrical design conditions with the layout planning conditions and confirm that the total number of modules, the number in series, the number in parallel, and the number of circuits are consistent.

Step 5: Confirm temperature characteristics and loss conditions

Once the panel settings are complete, review the temperature characteristics and loss conditions. PV modules do not always generate their rated power just because solar irradiance is strong. In practice, module output decreases as module temperature rises. Therefore, when evaluating energy production in PVSyst, a temperature model that reflects the temperature coefficient and installation conditions is important.

The temperature coefficient of power listed in the datasheet indicates how much the maximum power changes with an increase in temperature. In general, the higher the module temperature, the lower the power output. In summer or under poorly ventilated installation conditions, this temperature-related loss can become larger. In PVSyst, temperature-related settings are configured according to the module’s mounting condition and ventilation. The rate at which module temperature rises differs when modules are mounted close to a roof, installed on ground-mounted racks with good airflow, or integrated with building materials.

Loss conditions include mismatch losses, wiring losses, soiling losses, long-term degradation, and losses due to shading, among others. They may appear to be separate items from the panel settings themselves, but in fact they are closely related to the panel model and layout conditions. For example, if panels experiencing different irradiance conditions are mixed within the same string, the effects of mismatch and shading can become significant. Likewise, when surfaces with different azimuths or tilts are grouped into the same input, discrepancies with the actual generation characteristics tend to arise.

Soiling losses vary depending on the local environment. The condition of the panel surface differs by installation site — sand and dust, areas near farmland, industrial areas, coastal areas, or soiling after snowfall, for example. When entering soiling losses in PVSyst, it is important not to enter overly optimistic values, but to set them according to the maintenance plan and local conditions.

Shading losses are also related to panel settings. Surrounding buildings, trees, utility poles, fences, rows of mounting structures, or terrain undulations can cause only specific panels to be shaded. When shading affects some panels, it can impact the output of the entire string. When using PVSyst's 3D scene and shading analysis, it is necessary to ensure consistency between panel layout and string configuration.

Temperature characteristics and loss parameters are adjustment factors used to make predicted power generation closer to reality. However, tightening all of them isn’t necessarily better. Stacking large, unfounded losses leads to excessively conservative results. Conversely, underestimating losses produces predicted generation that is higher than actual. It is important to set explainable values based on the design objectives, site conditions, maintenance plans, and past performance.

Step 6: Review configuration errors based on the simulation results

The final step is to review the simulation results to check for configuration errors. After configuring the panels in PVSyst, it is dangerous to stop after only looking at the annual energy production shown on the results screen. Even if the output figures appear plausible at first glance, errors in the input conditions can make the results unusable for design decisions.

The first thing to check is the system capacity. Verify that the capacity calculated from the selected panel model, the nominal output, and the total number of panels matches the planned installed capacity. If there is a discrepancy here, possible causes include an input error in the number of panels, selecting the wrong model, or an omission in sub-array division. Before estimating power generation, always confirm that the installed capacity is correct.

Next, check the warnings and errors displayed by PVSyst. Messages may appear regarding voltage range, current limits, capacity ratios, excessive losses, insufficient settings, and so on. Calculations may still proceed even when warnings are present, but in practice you need to understand their meaning and take appropriate action. In particular, warnings about maximum voltage exceedance at low temperatures or the operating voltage being outside the permitted range should be checked carefully, as they can affect equipment safety and power generation performance.

Loss diagrams and monthly power generation are also important. In addition to annual generation, you should check which losses are large and whether the seasonal generation patterns look natural. For example, if a design that should have little shading shows large shading losses, there may be errors in the 3D layout or shading settings. If wiring losses are larger than expected, review the resistance values and cable length settings. If temperature losses are extremely large, check the mounting configuration and the inputs to the temperature model.

Also, check whether the monthly power generation corresponds with the local weather conditions and the orientation and tilt. South-facing tilted systems, east–west oriented systems, and low-tilt systems show different seasonal generation trends. If the results differ significantly from intuition, there may be an error in the azimuth, tilt angle, weather data, installation location, or panel settings.

Finally, we recommend listing the input conditions and cross-checking them against the design documentation. Organizing the panel model, number of panels, number of series, number of parallels, capacity, temperature coefficient, loss conditions, azimuth, tilt, and meteorological data will be helpful for internal verification and for explaining to customers. When using PVSyst, it is important not only to run the simulation but also to be able to explain the validity of the results.

Common mistakes and countermeasures in panel settings

In PVSyst panel settings, input mistakes can occur not only among beginners but also among experienced practitioners. One common error is selecting a model based only on its model name and skipping verification against the datasheet. Even similar model names can have different output ranges and electrical characteristics. Even if the model designation appears to match, there can be generational or specification differences, so it is essential to always confirm the main electrical characteristics.

A common mistake, coming in next, is matching only the total capacity without checking the validity of the number of series and parallel connections. Even if the generation capacity is close to the planned value, the actual design is not feasible if the input voltage or input current do not meet the equipment conditions. In PVSyst, you need to verify not only the consistency of capacity but also whether the string configuration is electrically valid.

Grouping panels with different orientation or tilt too much can also be a cause of failure. On rooftop installations, panels may be installed across multiple roof planes. Even for ground-mounted systems, orientation and tilt may not be uniform due to terrain. If these are combined into a single condition, the evaluation of power generation becomes coarse. If the conditions differ significantly, consider settings that match the actual situation, such as dividing into sub-arrays.

Another point to watch is not to underestimate the effects of shading. Even if the panel settings themselves are correct, if the surrounding environment and inter-row shading are not properly reflected, the estimated energy production may be higher than actual. Especially during periods of low solar altitude and in winter, even slight shading can affect generation. When evaluating shading in PVSyst, it is important to make the layout, racking height, row spacing, and the dimensions of surrounding obstacles as close as possible to on-site conditions.

Continuing to use the default temperature values can be problematic depending on the project. If installation configuration or ventilation conditions differ, the rate at which module temperature rises will also change. Installations close to the roof tend to trap heat, whereas ground-mounted racks may allow relatively better airflow. It is necessary to check temperature-related settings according to local site conditions.

To prevent these failures, standardizing the post-input verification procedure is effective. By checking the model, output, number of modules, number of modules in series, number of modules in parallel, capacity, voltage range, current range, loss conditions, and shading conditions in sequence, you can reduce serious mistakes. PVSyst is a highly capable simulation software, but it is the person responsible who must judge the validity of the input values. You need not only familiarity with the on-screen operations but also the ability to interpret the design conditions.

How to Handle On-site Information to Improve Accuracy in Practical Work

To improve the accuracy of panel settings in PVSyst, it is important to handle not only the module specifications but also the on-site information correctly. Even when using the same panels, the energy output of a solar power installation varies depending on the installation location, topography, and surrounding environment. Therefore, to bring the settings in PVSyst closer to reality, it is necessary to reflect the information obtained on site in the design conditions.

First and foremost, the orientation and tilt of the installation surface are important. Even if drawings treat orientation and tilt as fixed values, there can be subtle deviations on the actual site. For ground-mounted installations, check the grade of the prepared surface; for rooftop installations, check the slope of the roof surface and the influence of existing structures. If the input values for orientation or tilt are off, they will affect monthly generation and evaluations of peak hours. Especially with east–west layouts or low-tilt designs, small differences in conditions can show up in the generation curve.

Next, understanding surrounding obstacles is important. Buildings, trees, utility poles, fences, slopes, and adjacent equipment can cast shadows depending on the time of day and season. When configuring shading in PVSyst, you need to reflect the position, height, and distance of obstacles as accurately as possible. If you overlook the effects of shading, the calculated energy production may be higher than the actual output. Conversely, if you overestimate obstacles, you will estimate the energy production lower than necessary.

Topographic variation is also a major factor for ground-mounted installations. Even if a site is entered as flat, there may actually be slopes in the north-south or east-west directions. Because these affect inter-row shading, racking height, earthworks volume, and panel layout, it is desirable to reflect them in the design based on on-site surveys and topographic data. In recent years, there has been a growing trend to use high-precision positional information and point cloud data acquired on site to check for discrepancies between the design and the actual conditions.

When handling on-site information, be aware of which stage of the simulation it refers to. Approximate conditions may be acceptable in preliminary studies, but when data are used for detailed design or presentation materials, more accurate information is required. Using early-stage results directly for final decisions can lead to later design changes or revisions of estimated power generation. To make effective use of PVSyst results, it is important to increase input accuracy according to the stage of the study.

Also, it is important to keep the information collected on site in a form that can be checked later. Recording the orientation, tilt, survey points, positions of obstacles, photographic records, and the condition of the terrain can be used as the basis for inputs to PVSyst. Keeping on-site information is also effective for aligning understanding among the design team, construction personnel, and the client. The reliability of simulation results depends greatly not only on the software’s calculation accuracy but also on the accuracy of the on-site conditions entered.

Summary

Configuring panels in PVSyst is not simply a matter of selecting a model from the database. You need to verify the specifications of candidate photovoltaic modules, cross-check them against the models in the database, and if no matching model exists, address the issue by choosing a similar specification or registering a new one, and adjust the number of modules, series strings, and parallel strings to match the system conditions. Furthermore, confirm the temperature characteristics and loss conditions, and by reviewing configuration errors revealed by the simulation results, you can arrive at a power generation assessment that is usable in practice.

What is particularly important is not to judge solely by the nominal output. Items such as maximum power operating voltage, maximum power operating current, open-circuit voltage, short-circuit current, and temperature coefficients are directly tied to string configuration and compatibility with equipment. Even panels in the same power range may require different optimal numbers of series or parallel connections if their voltage and current characteristics differ. If PVSyst displays a warning on the screen, you should take it as a prompt to verify whether the design is actually viable in practice, not merely whether the calculation can be performed.

Also, improving the accuracy of panel settings requires a clear understanding of on-site conditions. Orientation, tilt, terrain, surrounding obstructions, shading, ventilation conditions, susceptibility to soiling, and so on all affect energy generation. To make practical use of PVSyst, it is important to link the specification figures with on-site information and be able to explain the rationale for the inputs.

In solar power system design and simulation, how closely you can align desk-based assumptions with actual on-site conditions determines the quality of the results. Accurately understanding site location, elevation, topography, surrounding structures, and the condition of the installation surface will make the input conditions for PVSyst more reliable. If you want to streamline simple on-site surveying, position verification, and point-cloud acquisition, using smartphone-mounted high-precision GNSS positioning devices like LRTK can help smoothly connect pre-design site assessment with post-construction verification. By combining PVSyst power-generation simulations with high-precision positioning data obtained on site, you can further enhance the planning accuracy and explanatory power of photovoltaic installations.