10 Basic Operations for Users Who Don't Understand the PVSyst Settings Screen

Table of Contents

• Why users often get confused by PVSyst's settings screens

• Basic Operation 1: Organize project information and storage locations first

• Basic Operation 2: Check the relationship between site conditions and weather data

• Basic Operation 3: Match azimuth and tilt angles to on-site conditions

• Basic Operation 4: Don't judge panel parameters by model name alone

• Basic Operation 5: Review the concept of PCS capacity and the oversizing ratio

• Basic Operation 6: Check the voltage range with the string configuration

• Basic Operation 7: Decide what to reproduce in the shading settings screen

• Basic Operation 8: Understand the meaning of default loss settings and adjust them

• Basic Operation 9: Decide the order in which to review the simulation result screens

• Basic Operation 10: Review input conditions before generating the report

• Tips for establishing PVSyst use in practical work

• Improving the accuracy of on-site information leads to better simulation quality

Why Users Often Get Confused by the PVSyst Settings Screen

Many practitioners researching how to use PVSyst first stumble over the large number of configuration screens. If you only want to calculate a solar power system's energy production, it may seem that entering the panel capacity and installation location will produce results immediately. However, in the actual interface multiple settings are linked—project information, site conditions, meteorological data, installation angle, equipment parameters, string configuration, shading, losses, simulation, reports, and so on. As a result, it becomes unclear where to start entering data, which values have a major impact on the results, and which items can be left at their default settings.

In real-world practice, simply running a simulation once is not sufficient. For internal reviews, client explanations, design changes, capacity comparisons, panel layout revisions, recalculations of expected power generation, and so on, the same project is examined repeatedly while being revised. If the initial settings remain vague, you will not be able to explain later why the results differ, and it becomes difficult to trace which change in conditions caused the change in power output.

When trying to understand PVSyst's configuration screens, the important thing is not to try to memorize all of the functions from the start. First, grasp the basic operations that are directly linked to power generation calculations, and understand what each screen is for. If you understand the role of each screen, you'll be less likely to get confused even when there are many configuration items. This article explains, for those who don't understand PVSyst's configuration screens, the 10 basic operations you should learn first in practical work.

Basic Operation 1: First Organize Project Information and Storage Location

When you start using PVSyst, the first thing to be mindful of is organizing project information and save locations. In power generation simulations, it is common to compare multiple design proposals even for the same power plant. Proposals with different panel capacities, different tilt angles, different PCS capacities, or modified shading conditions will accumulate, so if you don’t decide on a convention for file names and project names at the outset, you’ll later have trouble knowing which one is the most recent.

On the project information settings screen, it's useful to organize the project name, site name, design plan name, creation date, person in charge, and notes. If you simply save it with names like "solar project" or "test," you won't be able to determine what it contains when you look back after a few days. In practice, using a name that includes the location name, capacity, the type of plan being considered, and the last updated date makes it easier to share with other team members.

The storage location is also important. PVSyst data are managed with relationships among projects, meteorological data, equipment data, simulation results, and so on. If you proceed without understanding where the data are stored, problems can occur: necessary data may not be found when opened on another machine, past calculation results may not be reproducible, and missing files may arise when sharing within the company.

As a basic procedure, we recommend first establishing folder-management rules on a per-project basis and keeping working files separate from files prepared for submission. Rather than overwriting a file each time you modify a simulation, save significant changes as alternative versions so they can be compared later. Understanding the settings screen requires considering not only the input fields themselves but also the management approach — for example, which conditions to retain in which files.

Basic Operation 2: Confirm the relationship between site conditions and meteorological data

What is extremely important on PVSyst’s configuration screen is the setup of site conditions and meteorological data. In solar power simulations, the irradiance, ambient temperature, latitude, longitude, and elevation of the installation site have a large impact on the amount of electricity generated. Even if the panel and PCS settings are correct, if the site conditions and weather data are misaligned with the actual location, the reliability of the simulation results will decrease.

A common mistake beginners make is assuming that simply entering the installation location is sufficient. In reality, you need to verify how the site information is linked to the meteorological data. Even when using data from nearby points, weather conditions can vary greatly in mountainous areas, along the coast, in urban areas, or in snowy regions. If the candidate power plant site and the meteorological data point are far apart, it is important to be aware of how much that discrepancy may affect the results.

In the settings screen, verify that the latitude and longitude are correct, that the elevation is not grossly inaccurate, and that there are no anomalies in the time zone or regional settings. These may seem like minor items, but because they affect calculations of solar altitude and solar radiation, they should be checked at an early stage. Especially for overseas or remote projects, it is effective to confirm the coordinates rather than relying solely on place-name searches.

Because meteorological data serve as the baseline for comparing annual power generation, using different data for each design makes comparison difficult. If you want to compare panel or PCS conditions, the basic approach is to fix the meteorological data and change only the equipment and layout conditions. Conversely, if you want to examine differences in meteorological data, you need to compare them after aligning the other design conditions.

When using PVSyst, it’s easier to understand if you think of the Site Conditions screen not merely as a place to enter an address but as the screen that sets the assumptions for the entire simulation. By carefully checking this screen, you will improve your ability to explain the calculation results in subsequent steps.

Basic Operation 3: Adjust Azimuth and Tilt Angles to Match Site Conditions

On the installation angle settings screen, you enter the panel's azimuth and tilt angles. This is one of the basic operations in PVSyst that can directly affect power generation. The azimuth indicates which direction the panel is facing, and the tilt angle indicates how much it is inclined relative to the ground. Because both relate to how solar radiation is received, entering incorrect values can significantly change the simulation results.

What often confuses beginners is the reference direction for azimuths. If you enter the angles from drawings or field documents as-is without carefully checking the on-screen labels, the orientation can end up reversed. On the settings screen, you need to check which direction is used as the reference for defining positive and negative and verify that it matches the orientation shown on the drawings.

Regarding the tilt angle, it is not always sufficient to simply input a standard angle. For roof-mounted installations it is often set to match the roof pitch, while for ground-mounted systems the angle is determined by the racking design. Furthermore, snow load, wind load, constructability, maintenance, and the effects of surrounding shading also play a role. Therefore, in practice it is important to input an angle that can actually be implemented, rather than one that only maximizes power generation.

Also, when multiple orientations or tilts exist within the same site, a single configuration may not be able to represent the whole. When installing on multiple roof surfaces of a building, or when racking conditions differ by area to match the terrain, you should consider the conditions separately for each surface. In the PVSyst settings screen, it is important to enter data while organizing and clarifying what extent will be treated as a single design condition.

Azimuth and tilt angles are items that are easy to verify when reviewing the report later. When explaining them to clients or internal stakeholders, it is reassuring to align the drawings, site conditions, design policy, and input values so you can answer why those angles were chosen.

Basic Operation 4: Do not determine panel conditions based solely on the model name

On the panel settings screen, you select or enter the specifications of the solar PV modules to be used. A common misconception here is to assume that selecting the model name completes the configuration. In reality, you must verify multiple conditions that affect the simulation, such as output, voltage, current, temperature characteristics, dimensions, number of modules, and the installation method.

When you are not yet familiar with using PVSyst, you will often use the equipment information registered in the database as-is, but in actual practice it is essential to always verify it against the specifications. Even panels in the same capacity range can differ in open-circuit voltage, maximum power-point voltage, short-circuit current, and temperature coefficients. These affect string configuration and combinations with the PCS, so you should not rely on the model name alone.

Pay particular attention to voltage changes caused by temperature conditions. The voltage of a photovoltaic (PV) module varies with temperature: it is higher at low temperatures and lower at high temperatures. Therefore, when determining the number of panels, you need to check whether the input voltage will fall within the PCS's input voltage range. Even if the panel settings screen and the string settings screen appear separate, they are actually closely related.

Also, when entering the number of panels to be installed, verify that the count on the drawings, the count in the capacity table, and the count in the simulation all match. Even a small input mistake can alter the total capacity, which will change the annual power generation. When comparing multiple proposals, be aware of whether the panel count and capacity are changing as intended or are being held fixed.

When setting panel conditions, it is important not only to enter the values from the specification sheet but also to understand how those values will be used within the simulation. Because they affect energy production, voltage ranges, temperature losses, and layout planning, these are items within PVSyst’s settings screens that should be checked carefully.

Basic Operation 5: Confirm the Concept of PCS Capacity and Overloading Ratio

In the PCS settings screen, you check the relationship between the DC-side panel capacity and the AC-side conversion capacity. In photovoltaic power generation systems, the panel capacity is sometimes designed to exceed the PCS capacity. In this case, the concept of the oversizing ratio is important. In PVSyst's settings screen, the PCS capacity, the number of inputs, conversion efficiency, operating voltage range, and output limitations all affect the simulation results.

A common pitfall for beginners is assuming that panel capacity and PCS capacity should simply be the same. In reality, the appropriate capacity balance varies depending on solar irradiance conditions, temperature conditions, equipment utilization rate, output curtailment, installation orientation, shading conditions, and so on. Increasing the oversizing ratio makes it easier to secure output during low-irradiance periods, but it can also result in the PCS limiting output during times of strong irradiance.

In PVSyst, when the PCS capacity is insufficient or there are problems with the voltage range, warnings or inconsistencies may be shown on the settings screen. You should not ignore these messages; it is important to check why the warnings are appearing. Rather than simply getting the calculation to run, you need to adopt the perspective of verifying that the design is sound.

In PCS settings, handling conversion efficiency is also important. Conversion efficiency is not constant; it varies with load rate. Because efficiency changes at low, medium, and high output, it affects annual power generation. Even when using registered equipment data, verifying that it is consistent with the specifications increases the credibility of explanatory materials.

Also, when using multiple PCS units, pay attention to imbalances in the number of strings and the capacities connected to each PCS. Even if the total capacity matches, if the capacities connected to individual PCS units are unequal, the actual design intent and the simulation may diverge. On the PCS configuration screen, it is essential to check both the overall capacity balance and the individual configurations.

Basic Operation 6: Check the Voltage Range in a String Configuration

String configuration is one of the items in PVSyst's settings screen that practitioners tend to find difficult. A string is a unit made by connecting multiple panels in series. The voltage is determined by the number of panels connected in series, and the current and capacity configuration change with the number of parallel strings. If the string configuration is not appropriate for the PCS input conditions, the design is not valid.

The first things to check in a string configuration are the maximum voltage at low temperature and the operating voltage at high temperature. Because panel voltage rises at low temperatures, having too many panels in series can cause the PCS maximum input voltage to be exceeded. Conversely, because voltage falls at high temperatures, having too few panels in series can cause the PCS to fall below its operating range. The number of panels in series must be determined within a range that satisfies both conditions.

On the PVSyst screen you can check the number of strings, the number of modules in series, compatibility with the PCS input, and the assessment of the voltage range. If a warning appears, it may be resolved simply by changing the number of modules slightly, but because that affects the overall system capacity and the wiring plan, it is important not to change it lightly. Adjustments need to be made while cross-checking with the site layout and the electrical design.

Also, when multiple orientations or tilts are mixed, connecting strings with different conditions to the same PCS input can cause losses due to differences in power generation characteristics. On the settings screen, it is important not only to match the total capacity but also to confirm that the strings connected to the same input have consistent conditions.

The string configuration is a setting that affects not only power generation but also safety and equipment protection. When using PVSyst, it's easier to understand if you regard the string configuration screen not as a place to "match power output" but as a place to "keep the design within the equipment's operating range." Carefully checking this can reduce discrepancies between simulation results and the detailed design.

Basic Operation 7: Decide what to reproduce on the shadow settings screen

Shadow settings are an important operation in PVSyst for bringing simulated energy production closer to reality. In photovoltaic systems, shadows are caused by surrounding buildings, mountains, trees, utility poles, fences, adjacent rows of panels, and so on. Because shadows greatly affect energy production, you need to decide in the settings screen how much detail to reproduce.

A common misconception among beginners is thinking that the more finely they model shadows, the more accurate the results will be. Detailed reproduction is of course useful, but if the shapes and positions you input are inaccurate, making them more detailed will not increase the reliability of the results. What is important is to prioritize reproducing the elements that are likely to affect power generation. Nearby tall obstacles, terrain that casts shadows at the low solar elevation in winter, and shadows between rows of panels are particularly important to check.

On the shadow settings screen, it's easier to organize things if you consider distant shadows and near shadows separately. Distant shadows are elements such as mountains and terrain that affect how the sun appears. Near shadows are shadows caused by obstacles located on or near the site, such as buildings, equipment, mounting racks, surrounding structures, and adjacent panels. Both affect power generation, but the input methods and points to check differ.

Also, when configuring shadows, the accuracy of on-site survey data and layout drawings is crucial. If obstacle heights, positions, or distances are off, the timing of shadow occurrence and the extent of their impact will also be off. In particular, for ground-mounted power plants, the post-construction ground elevation, racking height, and row spacing are related to shadow effects. If settings are made based only on a desk-top schematic, calculations may be performed under conditions that differ from the actual site.

The shading settings in PVSyst are not just a screen for creating a 3D visual model. They are meant to reflect in the simulation the factors that cause a reduction in power generation. Therefore, it is important to configure them while judging how detailed the shadows should be, which obstacles can be omitted, and which conditions must always be reflected.

Basic Operation 8: Understand the meaning of the default loss settings and adjust them

On PVSyst's settings screen, you can enter various loss items. Items such as temperature losses, wiring losses, mismatch losses, soiling losses, equipment conversion losses, degradation, shading, and downtime are available to make the estimated energy production closer to reality. The important point here is that even if you use the default values as they are, you should understand what they mean.

Beginners often fall into the trap of trying to fine-tune every loss item in detail, which instead makes the rationale unclear. In practice, explainable assumptions are more important than detailed numbers that lack a basis. For example, when setting wiring losses, check that they are consistent with wiring length, voltage, current, cable conditions, and design policy. When setting losses due to dirt, consider the installation environment, cleaning frequency, and surrounding dust or snowfall.

Temperature loss refers to the phenomenon in which output decreases as panel temperature rises. Because heat-dissipation conditions change depending on the installation method, conditions differ between installations close to a roof and ground-mounted racking with good ventilation. It is important to check that the option selected in the settings screen matches the actual installation method.

Mismatch losses are losses that occur due to variations in characteristics between individual panels and non-uniformity between strings. They are also affected by shading, soiling, degradation, temperature differences, and other factors. Rather than simply entering a fixed value, being able to explain why you expect that level of loss will increase the credibility of the report.

Loss settings are tied to the design philosophy of whether you view energy production conservatively, in a standard way, or close to ideal conditions. If there are internal standards or conditions agreed with the client, you need to enter them accordingly. When using PVSyst, it is better to think of the loss settings screen not as a place to “fill in numbers” but as a place to “reflect actual operating conditions in the energy production.”

Basic Operation 9: Decide the order to view the simulation results screen

When you run a simulation, PVSyst displays many results. Annual energy production, monthly energy production, performance ratio, breakdown of losses, output limitations, shading effects, temperature losses, and so on—there are so many items to check that beginners often don't know where to look. To understand the results screen, it is helpful to decide in advance the order in which to view the items.

First, what I want to check is the rough plausibility of the annual energy production relative to the installed capacity. Verify that the result is not extremely large or small. Next, look at the monthly generation to confirm whether the seasonal variation is natural. Seasonal trends change depending on irradiance conditions and installation angle, but if there is an unnatural drop you should review shading, weather data, orientation, tilt, loss settings, and so on.

Next, what you should look at is the breakdown of losses. Looking only at the total generation, you can't tell where losses are occurring. Check whether losses due to temperature are significant, whether losses due to shading are significant, whether limitations on the PCS side are significant, or whether wiring and mismatch are having an effect. Understanding the breakdown of losses reveals the direction for design improvements.

Whether output limits are present is also important. In designs that raise the overloading ratio, output may be curtailed by the PCS capacity ceiling during periods of strong solar irradiance. By checking whether this limitation is within expectations or excessive, you can reassess the balance between panel capacity and PCS capacity.

On the results screen, it is important to read not only "how many kWh were generated" but also "why that result occurred." Because PVSyst reports contain a large amount of information and can feel difficult at first, checking in the order of annual values, monthly values, loss breakdowns, warning indications, and input conditions makes it easier to grasp the meaning of the results.

Basic Operation 10: Review Input Conditions Before Generating Reports

PVSyst reports are important documents used for internal review and customer presentations. However, if you do not review the input conditions before generating the report, you may end up producing materials based on incorrect assumptions. Even if the simulation results look plausible, if the input conditions are wrong the reliability of the presentation materials is reduced.

Before outputting the report, first confirm the project name and the design proposal name. When there are multiple similar proposals, an older proposal may be mistakenly output. Next, check the site conditions, meteorological data, panel capacity, PCS capacity, installation angle, string configuration, shading, and loss settings. These are important assumptions to be stated in the report and are items that are likely to be questioned later.

Particular care is needed when conditions are changed midway. In practice, it is common for issues such as the number of panels having been changed while the design proposal name remains outdated, the PCS capacity being changed but not reflected in the notes, or revised shading conditions being mixed with an old comparison report. Before submitting a report, you need to make clear under which conditions the results were calculated.

Also, check whether any warnings or caution notices remain. A warning does not necessarily mean something is wrong, but you should avoid submitting without understanding what the warning means. If a condition is unavoidable for design reasons, be prepared to explain why.

A report not only presents the results but also serves as documentation for preserving the input conditions and calculation assumptions. When using PVSyst, treating report output not as the final task but as a checking step to reconfirm the input conditions can reduce mistakes.

Tips for Establishing PVSyst Usage in Practical Work

To understand PVSyst's settings screens, it is more important to understand the connections between the input conditions than to memorize the operating procedures. Site conditions relate to the meteorological data, the installation angle relates to how solar radiation is received, panel conditions relate to the string configuration, and PCS conditions relate to output limitations and conversion losses. Each screen may appear independent, but they are connected in the final power generation.

To embed this in regular practice, it is effective to define an input-check workflow for each project. First confirm the project information and storage location, then set the site conditions and meteorological data, and review in the order of installation angle, panels, PCS, strings, shading, and losses. Finally, if you make it a habit to review the simulation results and the report, you can reduce missed settings and input errors.

Also, when comparing multiple scenarios, it is important to make clear what you change and what you keep constant. For example, if you want to compare differences in tilt angle, keep the meteorological data, panel capacity, PCS capacity, and loss settings the same. If you want to compare differences in PCS capacity, match the number of panels and the layout conditions. Clarifying the purpose of the comparison in this way makes it easier to explain the differences in the results.

When you are not yet familiar with the PVSyst interface, it is important not to try to use all of the features at once but to focus on the basic items. At first, work on a standard project to experience the entire flow from input to report output, and then deepen your understanding by exploring detailed shadow settings and adjusting loss items. As you become more accustomed to the operation, the many screens will come to be seen not as a burden but as an advantage that allows you to manage conditions in detail.

When multiple people within a company use PVSyst, sharing input rules and report review items can reduce variation among individual users. Deciding in advance which meteorological data to use, how to handle standard values for loss settings, how to name projects, and how to save comparison cases will make simulations easier to reproduce when reviewed later.

Improving the Accuracy of On-site Information Leads to Better Simulation Quality

To use PVSyst's settings screen correctly, both the operations within the software and the accuracy of on-site information are important. Power generation simulations are calculated based on the input conditions. In other words, if information such as the installation site coordinates, terrain, positions of obstacles, panel layout, orientation, tilt, and surrounding shading is ambiguous, no matter how carefully you operate the screen, the reliability of the results will be limited.

Especially when evaluating shadow effects and placement conditions, accurately understanding the on-site situation is indispensable. The heights of surrounding structures, elevation differences within the site, mounting-frame installation positions, and relationships with roads and slopes cannot always be fully captured by drawings alone. By leveraging location information and point cloud data obtained on site, it becomes easier to verify design conditions and grasp the scope of potential impacts.

What comes in handy here is LRTK, a high-precision GNSS positioning device that can be attached to and used with an iPhone. By utilizing LRTK, you can acquire high-precision position information on-site, streamlining tasks such as surveying potential sites for solar power installations, verifying installation positions, recording surrounding structures, geotagging photos, and acquiring point clouds. By aligning the coordinates and site conditions set in PVSyst not only with desk-based estimates but with measured information obtained in the field, the explanatory power of the simulation results is also enhanced.

To avoid getting lost when using PVSyst, it is important not only to learn how to operate the settings screens but also to prepare the input assumptions as accurately as possible. If you cover the basic operations—project information, meteorological data, installation angle, equipment conditions, string configuration, shading, losses, and report verification—and correctly understand the site’s location information and surrounding environment, the power generation simulation will become more practical for real-world use. Incorporating high-precision positioning devices such as LRTK into field surveys clarifies the basis for the conditions entered in PVSyst’s settings screens and makes the workflow from design study to the preparation of explanatory materials more reliable.