6 Steps to Proceed with Layout Creation in the PVSyst Manual

Table of Contents

• What to keep in mind before reviewing layout creation in the PVSyst manual

• Step 1: Organize the project conditions and design scope

• Step 2: Review considerations for orientation, tilt, and the mounting surface

• Step 3: Decide the assumptions for module placement

• Step 4: Adjust the layout to account for the effects of shadows

• Step 5: Confirm alignment with the electrical design

• Step 6: Review the layout based on the simulation results

• Common Mistakes in Layout Creation

• A practical, easy-to-use verification workflow

• Summary

Key points to note before checking layout creation in the PVSyst manual

Many people consulting the PVSyst manual about layout creation find themselves uncertain during the design of a photovoltaic system about which screens to check and in what order, how much input is needed for it to be reflected in the analysis results, and how to interpret the relationship between layout and energy production. PVSyst is not simply a tool where you enter the number of panels and get the output. Because azimuth, tilt, installation spacing, shading, strings, inverters, and loss conditions are all interconnected and appear in the results, getting the approach wrong at the layout stage will make it difficult to interpret the meaning of the analysis results later.

Especially when using PVSyst for the first time, the screen can look like it has many input fields, so it’s easy to become unsure where to start. However, what matters in practice is not learning all the functions at once, but organizing the information related to layout creation in sequence. First, check the site conditions of the project, decide the orientation and tilt of the mounting surface, establish the assumptions for module placement, and then review the results while checking consistency with shading and the electrical design. Grasping this workflow alone will greatly reduce the confusion when reading the PVSyst manual.

Layout creation is not the task of making a visual arrangement diagram. In practice, it is the process of establishing the assumptions needed to reflect design conditions in the energy production simulation. If you create only the layout while ignoring site topography, roof shape, surrounding obstacles, inter-row spacing, maintenance space, racking orientation, string configuration, and so on, the estimated energy production can appear larger than reality or, conversely, appear excessively low. Therefore, when consulting the PVSyst manual, it is important to be aware not only of the on-screen operations but also of which inputs affect which results.

Also, the layout in PVSyst is not a substitute for CAD drawings or construction drawings. It is easier to understand if you think of the division of roles as creating detailed construction drawings with other design tools, while using PVSyst to reproduce the placement conditions necessary for energy production assessment. In other words, creating a layout in PVSyst is not about producing drawings to directly manage construction accuracy, but about creating a design model to evaluate energy production, losses, and areas of impact.

This article explains, in six steps, the points that are easy to get confused about in practice for people who consult the PVSyst manual to check layout creation. Rather than requiring memorization of screen names, it is organized around the flow of design decisions so that even first-time users can understand the order in which to think.

Step 1: Organize the project requirements and the design scope

Before starting layout creation in PVSyst, the first thing to sort out is the project conditions. Depending on the size of the power plant, the installation location, whether it is roof-mounted or ground-mounted, fixed-tilt or tracking, and whether it is for self-consumption or for selling power to the grid, the parameters to enter and the verification items to prioritize will differ. Even if you proceed while consulting the PVSyst manual, if you don't decide the project's assumptions beforehand, you'll end up repeatedly going back and changing conditions mid-process.

The first thing I want to confirm is the meteorological conditions at the installation site. In PVSyst, meteorological data such as solar irradiance and temperature have a large impact on simulation results. Creating the layout itself may look like a placement task, but in reality power generation is evaluated in combination with the meteorological conditions. Therefore, if site selection and meteorological data settings remain ambiguous and you only create the layout, the final results will not be highly reliable.

Next, clarify the design scope. For rooftop installations, confirm how far the subject roof surface extends, which areas will be excluded from equipment installation, and how inspection walkways and evacuation routes will be handled. For ground-mounted installations, factors such as site boundaries, extent of land development (grading), slopes, maintenance access routes, fences, and locations of substation/transformer equipment are relevant. In PVSyst, it is not necessary to reproduce everything in detail like a drawing, but you must distinguish between areas that affect power generation and areas where installation is not possible.

A common mistake at this stage is to base the design solely on the area where panels can be placed and install the maximum number. If the aim is only to make the energy yield look large, increasing layout density can sometimes appear advantageous. However, in practice you must consider row-to-row shading, constructability, maintainability, electrical wiring, equipment placement, snowfall and wind conditions, and so on. When you review the layout creation section of the PVSyst manual, it is important not simply to increase the number of panels, but to proceed while confirming whether the layout is viable as a project.

When organizing the project conditions, it helps to decide the purpose of the analysis in advance. Whether it is a rough estimate, a basic design, a power generation evaluation for investment decisions, or a comparison of design-change proposals will change the required input accuracy. For initial studies, comparing multiple options with a rough layout is effective. On the other hand, for studies close to final, unless shading conditions and loss conditions are carefully incorporated, differences in results will be hard to use for design decisions.

To use PVSyst efficiently, it is also important not to try to create a perfect layout from the outset. Start by entering the broad installation conditions, check the results, and make adjustments when issues become apparent — this approach is more realistic. Rather than reading the manual from beginning to end, you will find it easier to develop a practical understanding by consulting the necessary sections in the order of project conditions, layout, shading, electrical configuration, and result verification.

Step 2: Review considerations for orientation, tilt, and mounting surface

The next important factor in layout design is the conditions of which direction and at what angle the modules are installed. Checking the azimuth and tilt settings in the PVSyst manual shows that these are fundamental parameters that directly affect energy production. In particular, for rooftop installations the azimuth and tilt often differ for each roof surface, and if you summarize the whole system under a single set of conditions, the actual energy yield is likely to deviate.

Orientation determines the direction from which sunlight is received. In typical projects in Japan, a south-facing orientation tends to be advantageous, but depending on roof shape and site conditions, an east-west layout may also be considered. In PVSyst, because orientation affects how solar radiation is received, it is important not to simply assume that “being close to south is fine,” but to correctly organize the conditions for each installation surface.

Tilt angle also affects energy output. Increasing the tilt can make it easier to receive solar radiation in winter, but it may also increase inter-row shading and affect wind loads and racking conditions. Conversely, reducing the tilt can suppress inter-row shading, but it may introduce other issues such as dirt accumulation, drainage, and reduced solar radiation capture. PVSyst makes it easy to compare energy outputs, so you can evaluate multiple tilt conditions to determine a suitable option.

In roof installations, it is important not to combine installation surfaces too much. For example, even on the same building the south-, east-, and west-facing surfaces, corrugated metal roofs, pitched roofs, and flat roofs have different conditions. Treating them all as the same surface will produce averaged results, even though shading behavior and generation patterns actually differ. When reading the PVSyst manual, it is easier to understand if you keep in mind how to divide the installation surfaces into units.

For ground-mounted installations, terrain and site development conditions affect how orientation and tilt are considered. On flat land it is relatively simple, but for sloping sites or sites that include embankments you need to consider the height of each panel row, how shadows extend, and the installation surface after earthworks. How much terrain to reproduce in PVSyst depends on the project's accuracy requirements, but at a minimum you should not ignore level differences or surrounding obstacles that have a significant impact on energy yield.

The key point of this procedure is not to treat azimuth and tilt as mere input values. In PVSyst, results are produced based on the input conditions, so if the assumptions are ambiguous, the results will be ambiguous as well. By organizing early in the layout-creation stage how installation surfaces are divided, the azimuth, the tilt angles, and the racking conditions, it becomes easier to proceed with alignment checks against subsequent shading analysis and electrical design.

Step 3: Define the assumptions for module placement

After organizing the approach to orientation and tilt, the next step is to determine the assumptions for module layout. Here, "layout" does not simply mean arranging modules; it is the task of deciding the overall configuration, including the number of columns and rows, spacing, direction, no-installation zones, and maintenance space. When checking layout creation in the PVSyst manual, you should not focus only on the placement operations but must make clear what assumptions the placement is based on.

The first thing to decide is the approach to mounting modules vertically or horizontally. Vertical and horizontal mounting change the required installation dimensions, how shadows are received, racking configuration, and wiring routing. For roof installations, the roofing material and support hardware conditions are involved, while for ground installations the racking specifications and constructability are relevant. In PVSyst the layout is reproduced in the form necessary for power generation assessment, but if the arrangement differs greatly from practical racking specifications it becomes difficult to use as a design.

Next, consider the inter-row spacing. Row spacing is related to the balance between energy yield and installed capacity. If you close the spacing, you can place more modules in the same area, but shadows from the front rows are more likely to fall on the rear rows. If you widen the spacing, shading effects are reduced, but the number of modules installed may decrease and the system’s installed capacity may become smaller. When creating a layout in PVSyst, it is important not to simply pursue the maximum number of modules but to assess the balance between shading losses and installed capacity.

For rooftop installations, how you handle no-install zones is also important. There are locations on the roof where modules cannot actually be placed, such as roof edges, ridges, valleys, snow guards, skylights, exhaust vents, HVAC equipment, maintenance walkways, and emergency escape routes. Whether you reproduce all of these in detail in PVSyst depends on the project, but any factors that affect energy yield and the number of modules should be reflected. A layout that ignores no-install zones may look like it has high energy production, but it can be heavily revised once the project moves into detailed design.

On ground-mounted installations, site edges, fences, access/maintenance roads, power conditioners, substation/transformer equipment, drainage facilities, slopes (embankments), and existing structures influence the layout. In particular, for large-scale projects, postponing aisles and equipment spaces can later force a substantial reduction in the number of module rows. Considering spaces other than the generation equipment from the initial layout stage in PVSyst reduces rework in later phases.

When arranging modules, symmetry and regularity are points you also want to check. A neatly arranged layout makes it easier to plan wiring and maintenance and to organize simulation conditions. Conversely, when roof shape or obstacles lead to an irregular layout, string configuration and shading effects tend to become more complex, so take care when interpreting the analysis results. While referring to the PVSyst manual, verify that the units of the layout and the units of the system configuration are not significantly misaligned.

The layout created at this stage is a starting point for comparison, not the final design. Rather than developing only one plan in depth at the outset, comparing versions that slightly vary row spacing, tilt angle, number of panels arranged, and installation area makes it easier to understand which elements affect power generation. Because PVSyst is well suited to such comparisons, when reading the manual it is recommended to learn by creating and comparing plans rather than by isolated operations.

Step 4: Adjust the layout to account for the effects of shadows

In layout design, the handling of shadows is especially important. In solar power generation, shadows cast by surrounding buildings, trees, utility poles, rows of mounting structures, rooftop equipment, and terrain affect power output. Many people who check layout creation in the PVSyst manual get stuck on the shadow settings and on interpreting the results. Shadows are not simply a matter of present or absent; their effects vary with season, time of day, solar altitude, mounting surface, and string configuration.

First, consider which shadows need to be reproduced. Trying to model every object on site in detail makes the work too complex. Rather than reproducing small distant objects that have little effect on power generation, it is more practical to prioritize checking buildings, trees, rooftop equipment, and panel rows that are likely to cast shadows on the module surface. The model in PVSyst should be created reasonably within the scope necessary for power output assessment.

On rooftop installations, shading from rooftop equipment is often a problem. Electrical cubicles, outdoor air-conditioning units, roof penthouses, handrails, exhaust ducts, and adjacent buildings can all cause shading. If modules are laid out while ignoring these shadows, the estimated output may be higher than the actual generation. Because shadows lengthen during periods of low solar altitude and in winter, placement needs to be adjusted while considering shading impacts over the year.

For ground-mounted installations, inter-row shading is a major consideration. When front-row modules cast shadows on rear rows, inter-row distance, tilt angle, racking height, and installation orientation affect the shading. It may not be realistic to eliminate inter-row shading completely, so you must decide as a design judgment how much loss to tolerate. When adjusting the layout in PVSyst, it is advisable to compare proposals with slightly different inter-row distances and check the balance between changes in system capacity and shading losses.

When considering the effects of shading, you need to be aware of electrical impacts as well as reductions in power generation. Even with the same shaded area, the effect on output varies depending on which modules are shaded and which strings they belong to. If partial shading is concentrated on certain strings, the loss can be greater than it appears. When dealing with shading in PVSyst, it is important to check the layout and the electrical configuration together rather than separately.

Also, rather than immediately making major layout changes after seeing the shading results, it is important to first check the causes. If losses are large, consider separately whether the inter-row spacing is insufficient, obstacles are too close, the tilt of the mounting surface is having an effect, or the orientation is unfavorable. If you reduce only the number of modules without identifying the cause, the points that should be improved will become unclear.

When studying the shadow settings in the PVSyst manual, it is useful in practice to make a habit of checking not only the numerical results but also the times of day and locations where shadows occur. For example, whether shadows appear only in the morning and evening or also during high-generation periods carries different weight in the design. Shadows that have little effect on annual energy yield and shadows that persistently occur during high-generation hours should be prioritized differently when planning countermeasures.

Step 5: Verify consistency with the electrical design

Once the layout has progressed to a certain point, verify consistency with the electrical design. In PVSyst, not only module placement but also module count, string configuration, inverter capacity, input range, and the approach to oversizing all affect simulation results. Even if the visual layout looks good, if the electrical configuration is impractical, it will not be a design usable in practice.

First, what you need to check is whether the number of modules you placed matches the system configuration. If the number of modules on the layout differs from the number in the electrical design, the assumptions for the energy yield assessment will be undermined. Even when entering data while referring to the PVSyst manual, you must always verify that the numbers are consistent across screens. Be especially careful when you have revised a design multiple times, as old module counts or old configurations may remain.

Next, we look at the layout at the string level. Which string a module belongs to depends on shading effects and voltage conditions. Mixing modules that are prone to shading with modules that are less prone to shading in the same string can be disadvantageous in terms of power generation efficiency. Of course, there are constraints imposed by actual wiring and equipment specifications, but even at the evaluation stage in PVSyst, it is important not to ignore the relationship between layout and string configuration.

Compatibility with the inverter is also important. DC-side capacity, AC-side capacity, input voltage range, maximum input current, and how MPPTs are used are related to the design conditions. As a result of increasing the number of modules in the layout, the capacity balance with the inverter can change. In PVSyst, because such configurations affect energy production and losses, the electrical configuration needs to be reconfirmed after layout changes.

Also, for projects with multiple orientations or multiple tilted installation surfaces, coordination with the electrical design becomes even more important. Treating east and west faces, south and north faces, or differently tilted surfaces in the same way forces together faces that have different generation patterns. Being deliberate in PVSyst about how to split systems and at what unit to evaluate them makes the results easier to interpret.

It is also necessary to review the approach to oversizing. Designs that make module capacity larger than inverter capacity are commonly considered, but as the oversize ratio increases, the impact of peak cut becomes more likely. If you change the layout so the number of modules increases or decreases, the oversize ratio will also change. When comparing layout proposals in PVSyst, it is important to evaluate not only the energy yield but also changes in peak cut and loss components.

What you should keep in mind with this procedure is not to separate layout and electrical design too much. Even if a plan is acceptable as a layout, its rating as a design proposal will drop if it is inefficient in relation to the strings and inverters. Conversely, even if it is electrically valid, a layout that ignores on-site shading and areas where installation is not possible cannot be used in practice. When reading the PVSyst manual, approach it on the assumption that layout, shading, electrical configuration, and losses are interlinked.

Step 6: Review the layout based on simulation results

The final step is to review the layout by looking at the simulation results. After creating the layout in PVSyst, you should not stop after simply generating the results. Check whether any issues caused by the layout appear in the results, and adjust the placement conditions as necessary. By adopting this review process, PVSyst can be used not merely as a calculation tool but as a tool for design improvement.

First, what you should verify is not to judge solely by the annual energy production. Annual energy production is an important indicator, but looking at that number alone will not tell you why the result occurred. By checking the breakdown of losses—shading losses, temperature losses, wiring losses, inverter losses, mismatch, peak clipping, etc.—you can identify layout-related issues. When viewing the results screen with reference to the PVSyst manual, it is important to look not only at the totals but also at the structure of the losses.

Shading losses and mismatches are especially sensitive to layout. If shading losses are large, you need to review row spacing, obstacles, how mounting surfaces are divided, and string configuration. If mismatches are noticeable, check whether modules under different conditions have been grouped too much into the same configuration, or whether shaded areas are concentrated in one part. Separating the causes makes it easier to determine which corrective actions will be effective.

Also check the monthly results. Even if there appear to be no major problems on an annual basis, trends can emerge such as large shading losses in winter, large temperature-related losses in summer, or peak clipping becoming noticeable only during specific periods. To assess the effect of a layout change, it is important to look at seasonal trends as well as annual values. In particular, inter-row shading tends to have more impact when the solar elevation is low, so it is meaningful to check the winter results.

When reviewing a layout, clarify the intended direction of improvement. The optimal proposal will vary depending on whether you want to maximize power generation, reduce shading losses, secure equipment capacity, improve constructability, or balance costs. PVSyst results are material for design decisions and do not automatically indicate the single correct answer. According to the objective, you need to determine which losses and to what extent they can be tolerated.

Also, when comparing multiple proposals, it is important not to change too many conditions at once. If you change orientation, tilt, number of panels, row spacing, inverter configuration, and loss conditions all at once, you will not be able to tell which change affected the results. For layout comparisons, first change only the row spacing, then only the tilt angle, and then the placement area; organizing the changes in this way makes it easier to evaluate.

When learning to create layouts from the PVSyst manual, it's important to understand not only the operational procedures but also the approach to checking and revising results. The first layout you create is a provisional draft that should be improved while reviewing the outcomes. With this premise, when the numbers differ from expectations you can remain calm and investigate the causes in the order of input conditions, placement, shading, electrical configuration, and losses.

Common Mistakes That Often Occur When Creating Layouts

One common mistake when creating layouts in PVSyst is placing too much priority on maximizing the number of installed modules. In solar power generation, the installed capacity increases if you can put more modules on the same site. However, if you cram them in while ignoring inter-row shading, maintenance space, electrical design, and constructability, actual generation efficiency can deteriorate and you may be forced to change the layout during construction. A high energy yield in PVSyst is meaningless if the layout cannot be realized on site.

The next most common mistake is postponing shadow checks. If you check shadows only after finalizing the layout, you may find that major revisions are necessary. In particular, shadows cast by rooftop equipment and adjacent buildings should be considered from the initial stages of placement. If you try to correct shading impacts later, you may need to revisit not only module placement but also string and inverter configurations.

Over-aggregating installation surfaces can also be problematic. Treating a roof with multiple orientations and slopes as a single condition can cause the results to diverge from reality. In PVSyst, the more you simplify the inputs the faster the work proceeds, but oversimplification lowers the accuracy of the assessment. How much detail to break out depends on the project, but differences that affect energy yield should be reflected as much as possible.

Inconsistencies with the electrical design also occur frequently. If the number of modules changes due to a layout modification but the system configuration has not been updated, the assumptions behind the results will be misaligned. Likewise, if the shaded area and the string configuration do not match, the actual losses may not be evaluated properly. When the layout is changed, it is essential to make a habit of checking the electrical configuration as well.

You can sometimes fail to interpret the results. If you judge a proposal solely by its annual energy production, you are likely to overlook the causes of losses. For example, even a proposal with high energy production may have issues such as large peak clipping, shading losses concentrated in specific periods, or poor maintainability. In PVSyst, it is important to check the breakdown of the results and understand the context behind the numbers.

Furthermore, there are failures that result from confusing initial studies with detailed studies. In initial studies, a rough comparison may be sufficient, but at stages close to investment decisions or finalizing the design, it is necessary to define more specific conditions. Conversely, overdeveloping details from the early stages makes it take too long to compare options. It is important to adjust the level of precision in layout creation according to the stage of the study.

Practical, Easy-to-Use Verification Workflow

When progressing with layout creation in PVSyst for practical work, deciding the order of inputs and checks improves efficiency. First, organize the project conditions and confirm the installation site and the weather conditions. Next, determine the orientation and tilt of the mounting surface and create the overall module layout. After that, check the impact of shading, reconcile with the electrical design, and finally review based on the simulation results. Fixing this workflow reduces the likelihood of missed checks.

In the initial stage, it is more effective to prepare a preliminary draft that can be reviewed early rather than aiming for perfection. By creating such a draft, you can see power generation, shading losses, equipment capacity, and layout-related issues. Rather than endlessly adjusting the layout without producing any results, it is easier to make decisions if you perform the calculations once and review the results.

Next, determine the scope of corrections while reviewing the results. If shading losses are large, reassess the spacing between rows and the layout around obstacles. If system capacity is insufficient, consider the installation area and the orientation of the modules. If peak cut is large, check the inverter capacity and the overloading rate. In this way, it is important to create a process that infers causes from the results and returns to the layout for corrections.

When discussing with internal teams and stakeholders, it makes it easier to build consensus if you can explain the differences between the layout proposals. Instead of simply saying "Plan A has higher power generation," clarify the design intent with statements such as "Plan A has a larger installed capacity but also increases shading losses," "Plan B has a smaller capacity but lower shading losses," and "Plan C prioritizes constructability." PVSyst results can be used as the basis for these comparative explanations.

When reading the PVSyst manual, it becomes easier to understand if you refer to the necessary sections according to the practical verification flow. Trying to memorize all items from the start is burdensome, but if you read in the order of project conditions, orientation and tilt, layout, shading, electrical configuration, and result verification, the meaning of each function will begin to connect. Learning the flow of design decisions is more important than memorizing the interface screens.

Also, when creating layouts it is important to retain the rationale behind the input values. If you cannot understand why a particular tilt angle was chosen, why a certain inter-row spacing was selected, or why a specific installation area was excluded, you will not be able to make decisions when reviewing the design later. Organizing the justification for these conditions not only as operations within PVSyst but also as design notes and study documents will make it easier to explain them to stakeholders.

Summary

When progressing with layout creation in the PVSyst manual, merely following the on-screen operations in order is not sufficient. What matters is understanding the flow of organizing the project conditions, deciding orientation and tilt, setting the assumptions for module placement, checking the impact of shading, ensuring consistency with the electrical design, and reviewing based on the simulation results. By following these six steps, layout creation in PVSyst becomes not just an input task but a practical design-review process for improving the proposed design.

What's particularly important is not to treat the layout as a finished product from the start. In PVSyst you can compare energy yield and losses while varying layout conditions. By gradually adjusting inter-row spacing, tilt angle, installation area, shading conditions, and the electrical configuration, and checking which elements are affecting the results, you can make more confident design decisions.

Also, rather than pursuing maximum power output alone, it is important to consider the balance among constructability, maintainability, shading losses, electrical design, system capacity, and cost. PVSyst’s results are material for design decision-making and do not automatically provide the single correct answer. For that reason, you should understand the meaning of the input conditions, interpret the breakdown of the results, and be prepared to revise the layout as necessary.

When using the PVSyst manual, it is efficient to first use these six steps as a framework to check the necessary items. Simply following the sequence—project conditions, orientation and tilt, module layout, shading, electrical configuration, and results verification—will greatly reduce uncertainty during the work. Even those creating a layout in PVSyst for the first time can follow this flow to prevent missing inputs and judgment errors, and to bring the simulation results closer to something practical for real-world use.