How to Use PVSyst Shadow Analysis | 5 Checkpoints for Interpreting the Results

PVSyst (officially styled as PVsyst) is simulation software used for the design and energy-yield assessment of photovoltaic power generation systems. When evaluating energy yield, it is important to consider not only solar irradiance and system capacity but also how shading effects are accounted for. In projects with buildings, forested areas, rows of mounting structures, parapets, utility poles, and surrounding structures in particular, if the assumptions about shading losses remain ambiguous, it can become difficult to explain the discrepancy between the expected energy yield and actual operational results.

PVSyst shadow analysis is not simply a task of checking whether there are shadows. It is a process of organizing the shape of near-field shading, sun position, azimuth, tilt, array layout, string configuration, electrical mismatch effects, and so on, while identifying which seasons and times of day are most likely to incur losses. When interpreting the results, do not judge solely by the loss rate displayed on the screen; you need to check, step by step, that the input conditions and the analysis results match the actual site conditions.

This article is organized for practitioners searching for "how to use PVSyst," covering everything from the basic concepts of shading analysis to five key points to check when interpreting the results, arranged in a form that can be safely used as a pre-publication article. Note that PVSyst screen names and operation procedures may vary by version; therefore, this article focuses on practical verification points rather than button operations limited to a specific version.

Table of Contents

• What can be checked with PVSyst shadow analysis

• Input conditions to organize before starting shadow analysis

• Check point 1 Read near-field shading and far-field shading separately

• Check point 2 Do not judge solely by the annual shadow loss value

• Check point 3 View shadow timing together with power generation contribution

• Check point 4 Confirm the effects of array layout and string configuration

• Check point 5 Organize results so they can be explained in the report

• Common mistakes in shadow analysis and how to review them

• Operational approach to linking on-site verification and simulation

• Summary

What can be checked with PVSyst's shading analysis

PVSyst's shading analysis is the process of incorporating shading losses into the simulation conditions when estimating the energy production of a photovoltaic power system. In solar power generation, the irradiance incident on the PV modules is the premise for power generation. Therefore, if irradiance is obstructed by surrounding buildings, terrain, or rows of racking within the facility, energy production will decrease. The core of shading analysis is estimating how much of this reduction to anticipate.

In shadow analysis, the shadows considered are broadly divided into distant shading and near-field shading. Distant shading refers to factors such as mountains, hills, and distant clusters of buildings that block sunlight during periods of low solar altitude. Near-field shading is caused by buildings, trees, fences, utility poles, signs, parapets, adjacent photovoltaic arrays, and other objects located close to the power plant. Distant shading is mainly treated as the horizon or obstruction line relative to the sun’s path, while near-field shading is generally evaluated based on three-dimensional objects and array layouts.

What matters in PVSyst shadow analysis is not the mere fact that a shadow exists, but how much that shadow affects power generation. For example, shadows of the same size that occur during low-irradiance periods in the morning or evening have a different impact on annual energy production than shadows that appear around midday when irradiance is high. Also, when a shadow covers part of a module, losses cannot always be judged simply by the area ratio. This is because the electrical interconnection of PV modules and strings can cause a partial shadow to produce a disproportionately large reduction in electrical output.

When reviewing shading analysis results, people tend to focus only on the annual shading loss rate. However, in practice it is important to also verify "why that loss is occurring," "which seasons and times of day it is concentrated in," "whether layout changes can improve it," and "whether the findings can be explained on-site." PVSyst can be used for detailed studies, but if the input conditions remain ambiguous, even results that look tidy may have weak consistency with actual site conditions.

Shading analysis is used in multiple situations, such as early-stage design, layout studies, power generation assessment, feasibility studies, and post-operation variance checks. Especially for rooftop installations, narrow sites, sloped terrain, or areas with many surrounding structures, performing shading analysis carefully makes it easier to reduce the risk of overestimating power generation. If you have the ability to interpret the results, you can turn the analysis from merely running a simulation into documentation that supports design decisions and explanations to stakeholders.

Input conditions to prepare before starting shadow analysis

The reliability of shading analysis is not determined solely by操作ing the analysis screen. Rather, how well site conditions are organized before the analysis greatly affects how readable the results are. Before performing shading analysis in PVSyst, you need to at least confirm the location information, azimuth, tilt, array layout, surrounding obstructions, terrain conditions, and equipment configuration.

First, the most important thing is the location information of the power generation facility. Because the sun's position changes with latitude and longitude, if the location settings are off, it will affect the direction and timing of shadows. Especially when handling multiple projects, if you proceed while reusing the settings from a previous project, the assumptions about weather conditions and the sun's position may not match the actual site. Before reading a shadow analysis, it is essential to confirm that the target site is set correctly.

Next, it is necessary to check orientation and tilt. The direction the solar PV array faces and the angle at which it is installed affect how shadows fall and how solar irradiance is received. The impact of the same obstructions changes depending on layout conditions—south-facing, east–west facing, single-sloped roofs, and low-tilt configurations on flat roofs, for example. It is important to review whether the orientation on the drawings, the orientation confirmed on site, and the orientation used in simulations all match.

Information about nearby obstructions is also important. Building heights, parapet heights, the positions of trees, the heights of adjacent equipment, the spacing between racking rows, and so on directly affect the results of shadow analysis. What is important to note here is that modeling obstructions in greater detail does not necessarily produce better results. Creating unnecessarily complex shapes increases the risk of input errors and makes explanations more difficult. In practice, it is necessary to appropriately simplify major obstructions that are likely to affect power generation and avoid spending too much time on details with little impact.

Also, the relationship between the array layout and the string configuration should be organized in advance. This is because not only which module rows are shaded, but also which circuit those modules belong to, changes how electrical losses manifest. When reading shadow analysis results, confusing a simple irradiance drop caused by shading with electrical mismatch losses makes root-cause analysis ambiguous. If the string configuration is not finalized at the design stage, it is safer to treat the results while clearly stating that they are based on provisional conditions.

When organizing input conditions, check drawings, on-site photos, measurement notes, and records of the surrounding conditions together. Shading analysis is not a task that can be completed solely on the screen; it is the process of translating field information into simulation conditions. By carrying this out carefully, it becomes easier, when reading the results, to judge “Is this loss reasonable?” and “Are the input conditions causing it to be over- or underestimated?”

Check 1: Read near occlusion and far occlusion separately

The first point to check when reading PVSyst shading analysis results is to treat near-field shading and far-field shading separately. Both reduce energy yield, but their causes and mitigation measures differ. If you combine them, the meaning of shading losses becomes blurred and it becomes harder to identify design improvements.

Far-field shading refers to factors such as mountains, hills, and distant buildings that block the sun’s path at low elevations. In many cases it affects times when the sun is low, such as mornings, evenings, and winter. Far-field shading often cannot be improved by small changes to equipment layout and is therefore frequently treated as a site-specific condition. Consequently, when the impact of far-field shading is significant, it must be described as a site-wide location condition for the entire power plant.

On the other hand, near-field shading is caused by structures around or within the installation. For rooftop equipment, this includes parapets, roof penthouses, piping, air conditioning units, and adjacent buildings. For ground-mounted installations, the preceding and following rows of racking, fences, trees, graded slopes, and surrounding facilities can be affected. Near-field shading can potentially be improved by reviewing the array position, row spacing, racking height, and the installation area.

When reviewing the results, first confirm which shading factor is causing the shading loss. Even if the annual loss is presented as a numerical value, the next steps differ depending on whether it is caused by distant shading or near-field shading. If distant shading is the main cause, focus on validating the simulation conditions and incorporating the loss into the project's feasibility. If near-field shading is the main cause, consider reviewing the layout and design for possible improvements.

When reviewing near-field shading, also verify that the shapes of the obstructions are not overly simplified relative to the site conditions. For example, if a structure that is actually tall is entered with a lower height, shading losses will be underestimated. Conversely, if small details with little effect are entered as large obstructions, losses can be overestimated. It is important to compare with site photos and drawings to confirm that the causes of the shading can be explained naturally.

In near-field shading analysis, also check whether the positional relationship between objects and the array is misaligned. If the azimuth is reversed or the perceived distances differ from reality, the times of day and the extent of shadowing can change significantly. Rather than judging from the results alone that “shading losses are small,” verify—by comparing the displayed shadows with the sun position—that they are consistent with the shadows that will occur on site.

Reading near-field shading and far-field shading separately also helps make shadow analysis more explainable as documentation. When explaining to stakeholders, separating "losses that are difficult to avoid due to surrounding terrain" from "losses that may be reduced through layout design" makes design decisions easier. The first step in shadow analysis is not to look at the magnitude of loss rates, but to classify and interpret the causes of the losses.

Checkpoint 2: Do not judge solely by the annual shading loss

What's particularly easy to overlook in shading analysis results is making judgments based only on the annual shading loss rate. Annual loss is useful for getting an overview, but on its own it does not allow you to fully understand how shadows form or where there is room for improvement. In practice, you need to look at a combination of annual figures, monthly trends, and time-of-day (hourly) trends.

Even if the annual shading loss rate appears small, the impact can be concentrated in specific seasons or times of day. For example, at an installation where shadows from surrounding buildings extend long into winter mornings, the annual figure may be small yet the reduction in power generation during winter can be pronounced. Conversely, even if the annual value looks somewhat large, if the shading is concentrated during periods of low solar radiation, the impact on project economics may be more limited than expected.

By looking at monthly shading losses, you can understand how shading changes with the seasons. In summer, when the solar altitude is high, shadows become shorter; in winter, when the solar altitude is low, shadows become longer. Therefore, the tendency for shading losses to increase in winter is natural. However, if losses are unusually large in only specific months, you should check whether there are errors in the obstruction settings or the array layout inputs.

Checking by time of day is also important. In solar power generation, shadows during periods of strong solar irradiance have a greater impact on output. Shadows in the early morning or late evening affect the potential generation time, but because the amount of solar irradiance is small, their contribution to annual generation may be limited. On the other hand, if shadows occur around midday, losses can be large even for a short time. When interpreting results, check both "when shadows occur" and "how much solar irradiance there is during those periods."

When looking at annual shadow-loss values, it is important to break them down to a level of detail that can inform design decisions. For example, even if there is a certain amount of annual loss, the appropriate response varies depending on whether the cause is shading from the front-row racking, surrounding buildings, or distant terrain. If the shading is from the front-row racking, candidates for mitigation include reviewing row spacing and tilt angle. If it is due to surrounding buildings, adjusting the installation footprint is a candidate. If it is distant terrain, the decision will mainly be to incorporate it as a site condition.

Also, while annual values are convenient for explaining to stakeholders, they are also figures that aggregate conditions. When reporting the results of shading analysis, organizing not only the annual loss rate but also the main periods when shading occurs, the primary causes of shading, and whether design-level countermeasures are feasible as a set makes them easier to use for practical decision-making.

Shadow analysis is not merely the task of determining "what percentage is lost annually." By using the annual value as an entry point and interpreting it across seasons, times of day, causes, and room for improvement, you can turn simulation results into information that can be applied to design and operations.

Checkpoint 3: View shaded time periods together with generation contribution

When interpreting shadow analysis results, you need to look at both the times when shadows occur and the contribution to power generation at those times. Even if a shadow's area or length appears large, its effect on power generation is not necessarily significant. Conversely, a shadow that appears small can have a large impact on power generation if it falls on a critical circuit during hours of strong sunlight.

In solar power generation, hours with higher solar irradiance contribute more to the amount of electricity produced. Generally, output during periods when the solar altitude is high and irradiance is more stable has a large impact on annual energy production. Therefore, it is important to determine whether shading is concentrated in the morning ramp-up hours, occurs around midday, or appears in the low-irradiance evening hours.

For example, if long shadows fall across part of an array on a winter morning, they may appear large on the screen. However, if solar irradiance is low at that time and the contribution to generation is limited, the impact on annual energy production may be smaller than expected. On the other hand, if shadows from parapets or roof penthouses fall on part of an array around midday, even a small shaded area warrants attention. When shadows occur during periods of strong irradiance, losses can be noticeable even over short periods.

When reading PVSyst results, check shadow losses in relation to solar altitude and solar azimuth. Verifying whether the direction in which shadows occur matches on-site intuition and does not contradict the seasonal path of the sun makes it easier to identify errors in the input conditions. For example, if a building on the east side should cause morning shading but the results show an effect on the evening side, you should suspect the azimuth or coordinate settings.

When assessing contribution to power generation, also review monthly generation and the breakdown of losses. For months with large shading losses, checking the simultaneous solar irradiance conditions makes it easier to understand how much shading affects project viability. Instead of simply concluding “shading losses are present, so it’s bad,” it’s important to determine how much loss occurs during the hours that actually contribute to generation.

Also, understanding the timing of shadows makes it easier to set priorities for design improvements. Rather than drastically changing the layout to completely eliminate shadows that occur during the low-solar-irradiance periods of morning and evening, it can be more effective to avoid localized shading that appears around midday. On limited roof surfaces or sites, it is difficult to reduce all shading to zero, so it is realistic to prioritize minimizing shading during the periods that contribute most to power generation.

When reading the results, it is also important not to be overly influenced by the appearance of shadows. If shadows are shown large on the simulation screen, they psychologically seem like a major problem. However, the impact on power generation varies depending on the time the shadow appears, the solar irradiance, the area affected by the shadow, and the circuit configuration. By checking the shadow’s timing together with its contribution to power generation, you can make decisions based on the actual impact on generation rather than on appearance.

Checkpoint 4: Verify the impact of array layout and string configuration

In shading analysis, the next important step is to check the impact of array layout and string configuration. In solar power generation, power loss is not determined solely by the shaded area. The way losses occur depends on which modules are shaded and which electrical circuit those modules are part of.

For example, even shadows of the same area exhibit different patterns of output loss depending on whether they are distributed across multiple circuits or concentrated on a specific circuit. When shading affects some modules, it can influence not only those modules but the output of the entire connected circuit. Therefore, in shading analysis, one must consider not only simple geometric occlusion but also be aware of electrical mismatch effects.

When evaluating array layouts, check to what extent the shadows from the front row fall on the rear rows. In ground-mounted and flat-roof multi-row configurations, row spacing, tilt angle, and racking height can cause shadows from the front row to reach the rear rows during winter. Increasing row spacing generally reduces shading, but it can decrease the capacity that can be installed on the same site. In other words, reducing shading losses and securing installed capacity are often a trade-off.

On rooftop installations, shadows from roof edges, parapets, rooftop penthouses, and equipment foundations can concentrate on specific arrays. In such cases, forcing modules into areas prone to shading can affect not only annual energy production but also output variability during operation. Designers have room to consider measures such as slightly shifting the layout, avoiding heavily shaded areas, or improving circuit separation.

When checking the string configuration, check which circuit contains modules that are prone to shading. If modules that are prone to shading are mixed in the same circuit with modules that are less likely to be shaded, output reduction can become noticeable under certain conditions. Where possible in the design, grouping the areas prone to shading or configuring circuits with modules that experience similar shading conditions will make it easier to reduce the impact of mismatch.

When reading PVSyst shading analysis results, it is important not to confuse geometric shading losses with electrical effects. Shadows visible on the 3D model indicate the areas where solar radiation is blocked. However, the ultimate impact on energy generation depends on module and circuit connections, the input conditions of power conditioners and inverters, and the design conditions. Therefore, when using shading analysis results to make design decisions, you should review the array diagram and the circuit diagram together.

Also, when simulations are run before the string configuration has been finalized, care is needed in how the results are handled. In initial studies, shading analysis may be conducted under approximate conditions, but treating those results as the final decision can lead to inconsistencies if design changes occur later. In reports and internal documents, it is safer to specify the configuration conditions at the time of the shading analysis and to include the assumption that these will be rechecked during the final design stage.

Checking the array layout and string configuration turns shading analysis from a mere energy-yield assessment into a tool for design improvement. Rather than just confirming that shading losses exist, by identifying which layouts or circuits are driving larger losses you can consider more realistic improvement proposals.

Checkpoint 5: Organize into a format that can be explained in the results report

The final check in a shading analysis is to organize the results so they can be explained as a report. Generating simulation results in PVSyst is important in itself, but in practice you need to present those results to stakeholders in a form that can be used for design and business decisions. Even if numerical results are produced, the credibility of the documentation is weakened if you cannot explain the assumptions and the causes of the shading.

What you should first check in the results report is whether the analysis conditions are clearly stated. Organize the assumptions that influence the results, such as the location under consideration, meteorological conditions, array azimuth, tilt, system capacity, obstruction settings, whether distant shading was considered, and the input range for near-field shading. Even if you extract only the shading loss figures, you will not be able to verify them later unless you know under what conditions those values were obtained.

Next, ensure that you can explain the breakdown of shading losses. Organizing the annual shading loss rate, monthly trends, main causes of shading, and the seasons and times of day when shading is greatest will make it easier for readers to understand the results. In particular, when losses are large, it is important to clarify whether the cause is surrounding topography, buildings, or shading between arrays. Once the cause is known, you can determine whether the loss can be mitigated or must be accepted as a site condition.

In reports, it is also important not to make overly definitive statements based on shading analysis results. Simulations are estimates based on the input conditions. Actual shading conditions can change due to future site alterations, tree growth, changes to surrounding buildings, equipment renovations, and so on. Therefore, rather than stating “this will definitely be the energy output,” it is safer to treat the figures as “estimates under the specified conditions.”

When explaining the results of shadow analysis, also summarize the potential for design improvements. For example, if shadow losses are large in a specific area, possible options include slightly reducing the installation area, revising the row spacing, or adjusting the circuit configuration of the shaded zones. However, proposed improvements involve other considerations such as a reduction in installed capacity, constructability, maintainability, and cost-effectiveness. The optimal solution should not be determined by shadow losses alone, but should be judged within the overall design conditions.

In report writing, it's also necessary to take care not to use too much technical jargon. While operational staff can share detailed loss items among themselves, when explaining to the client or to non-specialist internal departments, it's easier for them to understand if you plainly convey "which shadows at which locations, at which times, and to what extent affect power output." Rather than simply pasting PVSyst results, it's important to supplement them with the key points needed for decision-making in words.

Organizing results into a form that can be presented in a report also serves to verify work quality. If, when you try to explain it yourself, the assumptions are unclear or you cannot identify the causes of losses, you need to review the analysis conditions. Shadow analysis is not something that is finished on the screen; it only becomes useful in practice once it has been organized into information that stakeholders can accept and use.

Common Mistakes in Shadow Analysis and How to Review Them

In PVSyst shadow analysis, errors are more likely to arise from input conditions or misreading the results than from the operation itself. Understanding common mistakes will improve the accuracy when reviewing the results.

One common mistake is confusing the orientation. If the north on the drawings and the north in the simulation do not match, the times when shadows appear can be reversed compared with reality. Especially when working from roof plans or site plans, the orientation of the drawing may not correspond to the upward direction on the screen. If the shadow analysis results do not match on-site intuition, it is important to first check the orientation.

The next most common issue is insufficient height information. Even if the planar positions of obstructions are entered, if their heights are recorded lower or higher than they actually are, shading losses can change significantly. Buildings, parapets, rooftop structures, trees, and equipment can, with a height difference of just several tens of centimeters (several inches), alter the extent of shadows during periods of low solar altitude. It is advisable not to rely solely on site photos but to corroborate with drawings and measurements.

Be careful not to omit inputs for array height or racking conditions. If the module plane height, tilt, or spacing between racking rows differs from reality, inter-array shading will not be correctly reflected. This is especially true for low-slope rooftop installations, where slight differences in height or angle can affect winter shading. If there are design changes, confirm that those changes are also reflected in the shading analysis model.

Both over-simplifying obstructions and, conversely, modeling them in excessive detail are problematic. If you simplify too much, important elements that actually cast shadows will be omitted. If you model them too finely, input errors increase and the model becomes difficult to manage. In practice, you should prioritize the primary obstructions that affect power generation and simplify minor details as needed.

Also, care must be taken in how trees are handled. Trees change shape with the seasons and as they grow, so they are harder to treat as fixed obstructions like buildings. Because leaf loss, pruning, growth, and maintenance conditions affect how shadows appear, when incorporating them into shadow analysis it is advisable to record which state was assumed.

A common misinterpretation of the results is to treat all shading losses as if they were design failures. Shading losses include those that are difficult to avoid due to site conditions and those that can be improved through layout and circuit design. Rather than aiming to reduce them all to zero, decisions need to be made while balancing energy output, installed capacity, constructability, and maintainability.

The basic rule for review is to work backward from the results to the input conditions. If shading loss is larger or smaller than expected, do not just tweak the numbers; instead, sequentially check the position of obstructions, their height, azimuth, array layout, and string configuration. The most practical check is to compare the results with site photographs and drawings to confirm that the results can be explained naturally.

Operational Approach to Linking On-site Verification and Simulation

To make shading analysis useful in practice, it is important not to separate work in PVSyst from on-site verification. Simulation is an effective means of study, but the conditions entered are derived from on-site information. If analysis is carried out without sufficient on-site verification, the results may look neat yet fail to match the actual power generation conditions.

On site inspections, we broadly check for elements that could cast shadows. In addition to buildings and terrain, rooftop equipment, handrails, piping, signs, utility poles, overhead lines, trees, and structures on adjacent properties are also inspected. Especially in winter and at sunrise and sunset, when the sun’s elevation is low, shadows can extend much farther than expected, making it difficult to judge their impact from a single site visit. When taking photos, record them so that the relative positions of obstructions and the planned array area are clear, which will make later modeling easier.

Check for discrepancies between the drawings and the on-site conditions. There may be equipment on site that is not reflected in the drawings, or the dimensions on the drawings may differ from the actual installation. In particular, rooftop equipment on existing buildings may include devices or piping added later that create shading. Organizing the differences between the drawings and the site before running simulations will improve the reliability of the analysis results.

When using shading analysis to compare multiple layout options, it's important to keep the conditions consistent. If the inputs for obstructions or weather conditions vary between layouts, you won't be able to accurately compare shading losses. Be clear about which element you want to compare—row spacing, tilt angle, or installation area—and keep all other conditions as similar as possible during the analysis. This makes it easier to determine which design changes are affecting shading losses.

During the operational phase, there are occasions when actual power generation is compared with simulation results. If the assumptions used for the shading analysis are not recorded, it becomes difficult to identify the cause of any discrepancies. By recording the obstruction conditions used in the analysis, the equipment layout, circuit configuration, meteorological conditions, and loss settings, it becomes easier during operation to compare the "assumed shading" with the "shading that is actually occurring."

Furthermore, shadow conditions on site can change over time. Tree growth, the construction of nearby buildings, the addition of equipment, or roof renovations can create conditions different from the original shadow analysis. Therefore, shadow analysis should not be treated as a one-time task but should be reviewed when there are significant design changes or changes in the surrounding environment.

When linking on-site inspections and simulations, information sharing among stakeholders is indispensable. If those responsible for design, construction, maintenance, and business decisions each view shadows based on different assumptions, their judgments will diverge. When sharing the results of a shadow analysis, communicating not only the loss rate but also the causes of the shadows, the timing of their occurrence, the potential for improvement, and the underlying assumptions as a set makes it easier to build a common understanding.

Summary

PVSyst's shading analysis is an important process for evaluating the power generation of photovoltaic installations in a way that closely reflects site conditions. However, shading analysis is not sufficient if it only produces numerical values. By separating near-field and far-field shading, checking not only annual values but also seasonal and time-of-day variations, interpreting the timing of shading together with its contribution to power generation, and verifying the effects on array layout and string configuration, you can understand the results in a form that is usable in practice.

When reading the results of a shading analysis, it is fundamental to first verify the validity of the input conditions. If the location information, orientation, tilt, heights of obstructions, array layout, and circuit configuration do not match the on-site conditions, no matter how detailed the results are you may make an incorrect judgment. In particular, because shading losses can change with slight differences in on-site conditions, it is important to organize the assumptions based on drawings, photographs, and measurement records.

Moreover, shadow losses are not simply better the smaller they are. It is necessary to determine how far shadows should be avoided while balancing installed capacity, constructability, maintainability, and project viability. Trying to reduce all shadows to zero can actually decrease installed capacity and be detrimental to overall power generation and business viability. The important thing is to identify shadows that significantly affect generation and to separate losses that can be improved from those that should be accepted.

To put PVSyst to practical use, it is essential to organize the analysis results into materials that can be explained on-site. By整理ing not only the annual loss rate but also the causes of shading, the timing of occurrence, the extent of impact, proposed improvements, and the assumptions, the results become easier to use for design decisions and internal explanations. Simulations are not the final answer but rather material for consideration to help make better decisions.

Improving the accuracy of shading analysis also requires acquiring and organizing site information. If obstructions and installation conditions confirmed on site are properly reflected, PVSyst results are more likely to approximate actual conditions. Conversely, if site records remain vague, the reliability of the analysis results will also be unclear. When considering the design, construction, and maintenance of a power plant in an integrated way, it is important to manage and link simulations with site records.

If you want to make more reliable use of shading analysis, it is effective to organize the information collected on site and operationalize it by linking it to design conditions and energy yield assessment. Rather than taking PVSyst results at face value, by sequentially checking the input conditions, causes of shading, contribution to energy generation, and potential for improvement, shading analysis becomes a practical tool that supports both design decisions and explanatory documentation.