6 Points to Consider When Selecting a PCS in the PVSyst Manual

Table of Contents

• Basics to grasp before considering PCS selection in the PVSyst manual

• Equipment capacity and oversizing rate to check first when selecting a PCS

• Confirm the input voltage range and string design

• Read about the impact of temperature conditions on PCS selection

• Do not underestimate loss settings and conversion efficiency

• Incorporate grid interconnection requirements and output control into the design.

• Confirm the appropriateness of the PCS selection based on the report results.

• Points to note when using the PVSyst manual in practice

• Common Mistakes in PCS Selection and How to Review Them

• Summary

Fundamentals to Grasp Before Considering PCS Selection in the PVSyst Manual

When selecting a PCS in the design of a solar power generation system, many practitioners wonder whether they should simply choose equipment that matches the system capacity or whether they should make the decision while also considering losses and constraints from the energy yield simulation. Even when proceeding with the design while referring to the PVSyst manual, merely filling in the on-screen input fields in order is not sufficient to adequately judge the appropriateness of PCS selection. What is important is to view the PV modules, string configuration, DC input conditions, AC output conditions, temperature, losses, and grid interconnection conditions as an integrated whole and confirm that the design proposal is feasible.

PCS is the central device that converts the DC power generated by photovoltaic modules into AC power. Because it strongly influences the overall performance of the plant, it is necessary to carefully check the PCS capacity, number of input circuits, MPPT range, maximum input voltage, conversion efficiency, support for output control, and compatibility with the installation environment. In PVSyst, you can review annual energy production, loss breakdown, clipping, mismatch, temperature effects, and other items while directly or indirectly reflecting these conditions.

However, when reading the PVSyst manual, keep in mind that the numbers shown in the software do not directly determine construction decisions. PVSyst is very useful for design studies and comparative evaluations, but for the final PCS selection you must confirm manufacturer specifications, electrical design standards, grid interconnection requirements, construction conditions, maintainability, and the site environment together. In other words, what you should look at in PVSyst is not "which PCS is correct" but "whether this PCS configuration achieves a balanced trade-off among energy production, losses, voltage, capacity, and constraints."

Especially in recent years in photovoltaic power generation, designs that oversize the DC-side solar module capacity relative to the PCS AC capacity are commonly considered. Oversizing increases annual energy yield but causes clipping losses due to the PCS output limit. When considering PCS selection with reference to the PVSyst manual, how much clipping loss to tolerate becomes a major decision factor. It is not simply true that a higher oversizing ratio is better; the optimal balance varies with irradiance conditions, temperature, azimuth, tilt, PCS efficiency, feed-in conditions, and output control conditions.

In this article, I organize six points you should check in the PVSyst manual when considering PCS selection, from a practical perspective. Even those not familiar with operating PVSyst itself will be able to understand which items to look at to inform PCS selection decisions, as I explain in the order of capacity, voltage, temperature, losses, grid interconnection, and report verification.

Equipment capacity and overloading rate to check first when selecting a PCS

When considering PCS selection in the PVSyst manual, the first thing to check is the relationship between the PV array’s DC capacity and the PCS’s AC capacity. PCS capacity directly affects the plant’s rated output and grid connection capacity. Conversely, the module-side capacity increases or decreases depending on irradiance conditions and installation area. The ratio of DC capacity to AC capacity is the so-called overloading ratio.

The reason for considering the overloading ratio is that solar PV modules do not always deliver their rated output. Actual power generation fluctuates over time due to solar irradiance, temperature, soiling, degradation with age, orientation, tilt, shading, and other factors. Therefore, if you install only the same DC capacity as the PCS capacity, there may be more periods when the PCS is not fully utilized. For this reason, the DC side is often designed somewhat larger to boost generation in the morning and evening and during low-irradiance conditions.

However, if the overloading ratio is high, during periods of high irradiance the PCS may reach its AC output limit and DC power that could have been generated will be curtailed. This is called clipping loss. In PVSyst, you can check the losses due to PCS output limitation in the loss diagram and in the simulation report. When selecting a PCS, it is important to determine whether this loss is acceptable for return on investment and for generation planning.

What's important here is not to judge the oversizing ratio in isolation. Even with the same oversizing ratio, the way load is imposed on the PCS differs between projects that are south-facing with optimized tilt and projects arranged east–west where peaks are dispersed. In east–west configurations, generation peaks tend to be flatter, and clipping may be reduced even with the same PCS capacity. On the other hand, for south-facing, high-irradiance ground-mounted projects, the PCS is more likely to reach its upper limit around noon on clear days.

In practical work using the PVSyst manual, you first set the DC capacity and PCS capacity as a baseline, then compare multiple proposals with different PCS capacities. For example, you create a slightly smaller PCS option, a standard option, and an option with additional margin, and compare annual energy production, clipping losses, equipment costs, and grid interconnection conditions. By checking not only the comparisons within PVSyst but also the site's contracted capacity and interconnection constraints, you move closer to a PCS selection that is realistic from a business perspective rather than merely optimal in simulation.

When considering system capacity, it is important not only to look at the capacity of a single PCS but also at the number and arrangement of PCS units. Whether you install a small number of large-capacity PCS units or distribute multiple small- to medium-capacity PCS units will affect wiring distances, the scope of impact in case of a failure, maintainability, installation space requirements, and the DC collection scheme. PVSyst can model equipment configurations to compare energy production, but on-site constructability and maintenance access routes cannot be judged by numbers alone. Therefore, while reviewing PVSyst results, it is necessary to also consider the actual equipment layout and cable routing.

Verify the input voltage range and string design

The next important factor in selecting a PCS is the alignment between the DC input voltage range and the string design. The PVSyst manual shows the workflow for setting the number of modules in series, the number in parallel, the string configuration, and the inverter input conditions. What should be checked here is whether the string voltage falls within the PCS’s MPPT operating range, whether it exceeds the maximum input voltage, and whether there are any operational issues at low or high temperatures.

The voltage of a photovoltaic module changes with temperature. Generally, at low temperatures the open-circuit voltage increases, and at high temperatures the operating voltage decreases. If, at low temperatures, the string voltage exceeds the PCS maximum input voltage, equipment protection or safety issues may occur. Conversely, at high temperatures, if the operating voltage falls below the lower limit of the MPPT range, the PCS may be unable to extract power efficiently.

PVSyst allows you to verify whether a string configuration is appropriate by combining the module specifications and the PCS specifications. If warnings or errors appear, this may not be a simple input mistake but could indicate that the number of modules in series or the PCS selection itself is inappropriate. In particular, if you change the module model, change the PCS, or change the minimum temperature of the installation area, the previous string configuration may not necessarily be usable as-is.

One common oversight in string design is judging solely by average conditions. Even if there are no issues for much of the year, cold clear days in winter or high-temperature periods in summer can push the system outside the PCS input range. When reading the PVSyst manual, be conscious to check not only the expected energy production during normal operation but also that the voltage conditions remain within safe limits.

Also, a PCS may have multiple MPPT inputs. If strings with different orientations or tilts are connected to the same MPPT, mismatch losses can increase due to differences in generation characteristics. For example, combining east- and west-facing arrays, roof surfaces with different tilt angles, or rows that are shaded and rows that are not into the same input can make it difficult for the PCS to track the optimal operating point. In PVSyst, you can also compare these effects by separating and evaluating array configurations and subarray settings.

When selecting a PCS, it is also important to ensure that the number of input circuits is sufficient. In projects with many strings, if the PCS lacks enough inputs the design of combiner boxes and collector panels can become more complex, and cable losses and installation effort may increase. Conversely, choosing a PCS with an excessive number of input circuits can drive up equipment costs and required installation space. In PVSyst simulations, you should evaluate not only the energy yield but also whether the actual string assignment can be feasibly realized.

Reading the Impact of Temperature Conditions on PCS Selection

When selecting a PCS, addressing temperature conditions is also essential. In photovoltaic simulations, meteorological data, module temperature, ambient temperature, and wind conditions all affect the energy yield. When reviewing temperature-related settings in the PVSyst manual, it is important to understand them not only as factors that change module output but also as elements that influence the PCS input voltage and conversion efficiency.

When module temperatures rise, the generation voltage generally decreases and output also falls. During high temperatures in summer, the operating voltage of the solar array can drop and may approach the lower limit of the PCS's MPPT range. If there is insufficient margin when selecting the PCS, these temperature conditions can increase generation losses. Conversely, during low temperatures in winter the open-circuit voltage rises, so it is necessary to check the number of modules in series to ensure the maximum input voltage is not exceeded.

On PVSyst, annual power generation simulations are performed based on meteorological data for the installation area, but it is also necessary to be aware of site-specific temperature environments. For rooftop installations, module temperatures tend to rise depending on the heat of the roofing material, ventilation conditions, and mounting height. For ground-mounted installations, there can be good airflow, but local heat can build up due to developed sites or surrounding terrain. When structural conditions are atypical, such as in agrivoltaic or carport-type systems, it is necessary to consider both temperature and solar irradiance.

The installation environment of the PCS unit is also important. Because the PCS generates heat during conversion operation, output derating or efficiency degradation may occur in high ambient temperature environments. PVSyst does not reproduce the PCS unit’s thermal environment at a detailed construction level, but during the design phase it is necessary to check the PCS installation location, ventilation conditions, presence or absence of direct sunlight, and maintenance space. For outdoor installations, consider summer solar irradiation and enclosure temperature, and in snowy regions also consider snow removal and ensuring intake and exhaust ventilation.

Temperature conditions also affect the appropriateness of PCS capacity. In high-temperature regions, module output tends to decrease, so clipping losses may appear relatively small even at the same oversizing ratio. Conversely, in regions with low temperatures and strong irradiance, instantaneous output can rise and more easily reach the PCS limit. In other words, when considering the oversizing ratio for PCS selection, regional temperature characteristics cannot be ignored.

If you plan to use the PVSyst manual in practice, it's important not to leave the temperature-related settings at their default values, but to review whether they match the project's installation conditions. In particular, for rooftop installations, ground-mounted systems, pitched roofs, snowy regions, and high-temperature regions, the impact of temperature conditions on energy production and PCS behavior varies. To improve the accuracy of PCS selection, temperature conditions should not be treated as mere background data but should be considered as critical factors affecting DC voltage, output reduction, clipping, and equipment lifetime.

Do not underestimate loss settings and conversion efficiency

During PCS selection, confirming the loss settings and conversion efficiency is also important. When running simulations while referring to the PVSyst manual, it's easy to focus only on the power generation results, but in practice reading the loss breakdown reveals whether the PCS selection is appropriate. Losses related to the PCS include inverter conversion losses, losses due to output limiting, losses from operating outside the MPPT range, wiring losses, mismatch losses, and so on.

PCS conversion efficiency is the efficiency when converting direct-current (DC) power to alternating-current (AC) power. Specification sheets may list values such as maximum efficiency or European efficiency, but in actual operation the efficiency varies with the load factor. If a PCS operates at low load for long periods, selecting it based solely on maximum efficiency may result in overall annual performance falling short of expectations. PVSyst can run simulations that reflect the PCS efficiency curve, enabling comparisons that consider the equipment’s efficiency characteristics.

However, choosing a PCS based solely on conversion efficiency is risky. Even if the efficiency is slightly higher, if the input range does not match the project, the number of circuits is insufficient, it is not suitable for the installation environment, or maintainability is poor, it can be disadvantageous overall. When selecting a PCS, you need to evaluate efficiency, capacity, input conditions, ease of installation, maintainability, and cost together.

What you should particularly check in the loss settings is the clipping loss. In an oversized design, the AC output limit of the PCS causes periods when generation peaks are constrained. If PVSyst results show large clipping loss, the PCS capacity may be too small. However, a clipping loss close to zero is not necessarily desirable. Making the PCS capacity too large increases equipment costs and also affects contracted capacity and grid interconnection conditions. The important thing is not to eliminate losses completely but to ensure a balance between commercial viability and energy generation.

Wiring losses also affect PCS selection. Depending on the PCS location and the number-of-units configuration, the cable distances on the DC and AC sides will change. If PCS units are distributed close to the arrays, DC cable lengths can sometimes be shortened, but AC-side collection and maintenance can become more complex. Conversely, concentrating PCS units improves maintainability while lengthening DC cables, which can increase losses and voltage drop. When setting wiring losses in PVSyst, it is necessary to confirm that they are consistent with the actual layout plan.

Mismatch losses must not be overlooked. Variations in modules, azimuth differences, tilt differences, shading, and differences in string length can cause the characteristics of the power input to the PCS to be inconsistent. If the PCS's MPPT configuration is insufficient, it may not be able to absorb these differences, leading to increased losses. If the losses related to mismatch or shading are large in PVSyst's loss diagram, it is necessary to review the PCS input grouping and string configuration.

When using the PVSyst manual, it is important not to judge based solely on the final annual energy yield, but to analyze the causes by type of loss. Two scenarios that appear to have the same annual yield may differ: one may have large conversion losses while the other suffers from significant clipping losses. If the makeup of losses is different, the design points that need improvement will also differ. In PCS selection, it is essential not just to consider the absolute energy yield but to understand why that result occurred.

Incorporate grid interconnection requirements and output control into the design

PCS selection is not determined solely by the internal efficiency of the power generation equipment. Grid interconnection conditions and the ability to comply with output control are also important decision-making factors. When setting the PCS in the PVSyst manual, it is necessary to consider not only PCS capacity and losses but also the capacity that can actually be connected to the grid, the assumptions for output control, power sales conditions, and the constraints at the point of interconnection.

In photovoltaic power systems, the PCS's AC capacity affects the grid interconnection capacity. If the interconnection-capable capacity is limited, increasing the DC side may not fully realize the generated power due to constraints on the PCS output and the grid side. Over-sizing design aims to increase annual energy generation by increasing DC capacity, but in regions or under conditions where output curtailment occurs frequently, the effect of the added DC capacity can be reduced.

In PVSyst, you can analyze scenarios while reflecting output limits and grid-side constraints as fixed conditions. The important point here is to evaluate based not on the power plant’s maximum generation capacity alone but on the amount of electricity that can actually be used or sold. Increasing PCS capacity to raise peak generation may yield limited investment returns if the grid suppresses output. Conversely, appropriately limiting PCS capacity and adjusting the DC side can sometimes improve the balance between cost and energy generation.

Grid interconnection requirements also involve power factor, voltage rise, protection coordination, remote output control, and integration with monitoring equipment. You cannot determine all of these solely from a PVSyst simulation, but they are items that must be confirmed when selecting a PCS. Especially for high-voltage and extra-high-voltage projects, it is necessary to ensure alignment not only with the PCS's standalone specifications but also with the substation/transformer equipment, supervisory control and monitoring, protective relays, and communication requirements.

For self-consumption projects, the approach to selecting the PCS changes further. In projects intended for selling power, annual generation and the amount sold are the main evaluation metrics, but for self-consumption projects alignment with the demand curve is important. At facilities with high daytime loads, increasing PCS capacity may allow peak generation to be utilized. Conversely, at facilities with large surpluses during holidays or low-load periods, it is necessary to consider PCS capacity, output control, and integration with batteries. Even when using PVSyst, it is important to focus not on simple annual generation figures but on the amount of usable energy and how surpluses are handled.

When selecting a PCS, you should also take potential future operational changes into account. Whether a battery may be added later, output control rules may change, or demand-side equipment may be increased or decreased will affect the optimal PCS configuration. While it is important to finalize the current design with reference to the PVSyst manual, in practice — assuming long-term operation — you should distinguish between parts that are difficult to change and parts that can be modified.

Verify the validity of PCS selection based on the report results

After configuring the PCS in PVSyst, review the report results to assess the suitability of the selection. What to look at here is not just the annual energy production figures. You need to comprehensively check the loss diagram, monthly energy production, inverter losses, clipping, the system performance ratio, warnings about input voltage, and the effects of shading and mismatch.

First, I want to check whether losses related to the PCS are becoming excessive. Inverter conversion losses will occur to some extent, but if there is a large difference compared to other options, it may indicate that the PCS efficiency characteristics or load factor are mismatched. If clipping losses are large, it could be that the overloading ratio is too high, the PCS capacity is too small, or generation peaks are too concentrated due to site/layout conditions.

Next, examine the monthly trends. Even if the annual total looks fine, losses may be concentrated in specific seasons. For example, if clipping is frequent during the cool yet high-irradiance periods of spring or autumn, reconsidering PCS capacity might be effective. If generation does not increase as expected in summer, you need to check temperature losses, MPPT range, and wiring losses. If shading or low-temperature voltage issues appear in winter, review the string configuration and installation layout.

In PVSyst reports, the performance ratio is also an important indicator. The performance ratio is a metric for assessing how efficiently the actual system generates electricity compared to ideal conditions. However, a high performance ratio does not always mean a good design. Because interpretation varies with overloading ratio, weather conditions, output control, and how shading is handled, when selecting PCS the performance ratio should not be judged on its own but read together with the loss breakdown.

Do not underestimate warnings and error messages. In PVSyst, if the PCS and string configuration do not match, warnings about input voltage or inverter capacity may appear. If you ignore these and proceed with the simulation, you may end up evaluating a design proposal that would not be viable in reality. In particular, warnings regarding maximum input voltage, MPPT range, and recommended capacity ratio are important information that can lead to revising the PCS selection.

A useful approach for reviewing reports is comparing multiple proposals. By comparing proposals that vary PCS capacity, the number of units, string configuration, or adjust azimuth and tilt, you can see which factors affect power generation and losses. Looking at a single proposal alone makes it difficult to judge whether the numbers are good or bad, but comparing them clarifies the basis for design decisions.

Also, the report results will be used as explanatory material for stakeholders. Designers, construction personnel, project owners, financial institutions, maintenance personnel, and others have different points of interest depending on who is viewing it. When explaining PCS selection, it is important not merely to say "we chose this PCS," but to be able to explain "with this capacity ratio, clipping losses are contained at this level, input voltage conditions are acceptable, and consistency with the grid interconnection capacity is maintained." The PVSyst report serves as material for organizing that rationale.

Points to Note When Using the PVSyst Manual in Practice

When proceeding with PCS selection while referring to the PVSyst manual, the most important thing to watch out for is not to confuse the software’s input procedures with design decisions. The manual is useful for understanding how to operate the software, but it will not automatically determine which PCS is optimal for the project. In practice, after correctly entering data according to the manual, a designer must interpret the results.

First, careful handling of equipment data is required. You must verify that the PCS and module data registered in PVSyst match the specifications actually planned for adoption. If you substitute equipment that only has a similar model, the input voltage range, efficiency, capacity, and number of circuits may differ from the actual equipment. If you use simulations as the basis for PCS selection, it is important to cross-check the specification sheet with the settings inside PVSyst.

Next, verify the consistency of the meteorological data with the on-site conditions. In PVSyst you select meteorological data for simulations, but if the actual site is in mountainous areas, coastal areas, snow-prone regions, high-temperature regions, or on urban rooftops, data from a representative location alone may not adequately reflect the site-specific characteristics. When selecting a PCS, you need to be aware of the effects that temperature and solar irradiance conditions have on PCS operation, not just the power generation.

The handling of shadows also affects PCS selection. For arrays that are partially shaded, string configuration and MPPT separation are very important. If shadow settings in PVSyst are simplified too much, problems relevant to PCS selection can become less apparent. In particular for rooftop projects, roof penthouses, guardrails, adjacent buildings, air-conditioning equipment, utility poles, and trees can create shadows. Even in ground-mounted projects, surrounding terrain and inter-row shading affect energy production. In PCS selection, it is necessary to consider even which input to connect the shaded strings to.

Installation constraints must not be forgotten. Even if a string configuration works in PVSyst, it may be difficult to implement in practice due to constraints such as the actual roof shape, cable routes, combiner box locations, PCS installation locations, fire compartmentation, and maintenance space. Especially for installations on existing buildings, equipment delivery and handling, installation loads, cable penetrations, work requiring power outages, and maintenance access routes can become problematic. When selecting a PCS, it is important to iterate between the simulation results and the on-site conditions.

Furthermore, it is necessary not to over-rely on PVSyst results. Simulations are predictions based on the input assumptions. If the assumptions change, the results will change. Even if PCS capacity is numerically optimized, in actual operation an increase in output curtailment, soiling or degradation greater than expected, or changes in demand conditions may prevent the expected benefits from being realized. During design, it is desirable to check results under multiple conditions, as in a sensitivity analysis, and make decisions with sufficient margin.

Common Mistakes in PCS Selection and How to Review

One common mistake when selecting a PCS is choosing equipment based solely on capacity. For example, simply deciding to pick a high-capacity PCS because the solar array capacity is large, or a small-capacity PCS because the interconnection capacity is limited, can lead you to overlook input voltage, MPPT configuration, oversizing ratio, losses, and constructability. Even when using the PVSyst manual, you should not be satisfied with capacity settings alone; you need to check the loss breakdown and warnings.

Another common mistake is deciding the oversizing ratio solely by a single, uniform guideline. General guidelines are useful as references, but the optimal ratio varies depending on a project’s solar irradiation conditions, orientation, tilt, temperature, output control, and electricity sales conditions. If you set the oversizing ratio in PVSyst without comparing multiple scenarios, clipping losses may be larger than expected, or conversely PCS capacity may become excessive and investment efficiency may suffer.

Insufficient verification of the string configuration is also a major cause of failure. If the number of modules in series is not appropriate for the PCS’s maximum input voltage and MPPT range, problems can occur at low or high temperatures. If you proceed with the design while overlooking PVSyst warnings, equipment changes or wiring modifications may become necessary in later stages. When reviewing, recheck the minimum temperature, maximum temperature, module specifications, and PCS specifications, and adjust the number of modules in series and the number in parallel.

In projects with shading, the importance of MPPT separation is often underestimated. Combining shaded strings and unshaded strings on the same MPPT can reduce overall power generation efficiency. It is effective to check the impact of shading in PVSyst and, if necessary, modify the PCS input configuration and string allocation. In some cases, simply reviewing the string grouping can improve losses more than changing the number or model of PCS.

Mistakes are sometimes made by judging solely on PCS efficiency. A PCS with a high maximum efficiency may be attractive, but you must examine how its efficiency will be at actual load factors, whether it matches the input conditions, and whether maintainability can be ensured. It is important to check the annual operating profile with PVSyst and evaluate it including the effects of low-load periods and peak periods.

You should also avoid the mistake of postponing grid interconnection conditions. Even if the design indicates high generation, the actual volume of electricity that can be sold may be limited by interconnection capacity and output-control conditions. When proceeding with PCS selection, it is necessary to confirm grid-side constraints and reflect them in the assumptions for PVSyst. In particular, for large-scale projects or regions subject to output control, it is important to carefully examine the relationship between PCS capacity and project viability.

The fundamental principle of a review is to break down the causes. Rather than simply changing the PCS because annual energy production is low or increasing capacity because losses are large, check which losses are large, in which season they occur, and whether they are due to voltage conditions, capacity conditions, shading, or wiring. By interpreting the PVSyst report and identifying the root cause of the problem before modifying the design, you can avoid unnecessary equipment changes.

Summary

When considering PCS selection in the PVSyst manual, it is important not only to memorize the operating procedures but also to have the perspectives necessary for design decisions. The PCS is a central device that affects the output, efficiency, losses, grid interconnection, and maintainability of a photovoltaic power system. Therefore, it is necessary to comprehensively check not only the capacity but also the input voltage range, string configuration, temperature conditions, conversion efficiency, breakdown of losses, output control, and grid interconnection requirements.

The first thing to look at is the relationship between DC capacity and AC capacity. Properly setting the oversizing ratio can increase annual energy production, but if it is set too high, clipping losses will increase. In PVSyst, it is important to compare multiple scenarios and check the balance between energy production, losses, and equipment costs.

Next, check the input voltage range and string design. You must verify that the maximum voltage at low temperatures, the operating voltage at high temperatures, the MPPT range, and the number of input circuits comply with the PCS specifications. If this is done incorrectly, the electrical design may not be viable even before considering power generation.

Temperature conditions also have a major impact on PCS selection. Module temperature affects output and voltage, and the PCS unit’s installation environment influences efficiency and output curtailment. It is important to check PVSyst’s meteorological data and temperature settings and to run simulations based on assumptions that match the site conditions.

When checking loss settings and conversion efficiency, it is necessary to look not only at the annual power generation but also at the breakdown of losses. By checking inverter losses, clipping losses, wiring losses, and mismatch losses separately, you can see whether you should change the PCS capacity, review the string configuration, or improve the placement and wiring.

Don't forget grid interconnection conditions and output control. The amount that can be generated, the amount actually usable, and the amount that can be sold are not necessarily the same. Even if you increase the PCS capacity, if there are constraints on the grid side, the investment effect may be limited. When comparing design proposals in PVSyst, you need to make judgments that include project conditions and interconnection conditions as assumptions.

Finally, it is important to be able to explain the validity of the PCS selection using the report results. By checking the annual energy production, loss diagrams, monthly trends, warnings, and performance ratio, and being able to explain to stakeholders why that PCS configuration is appropriate, the reliability of the design is enhanced. The PVSyst manual is an entry point for understanding the operation, but in practice you need the ability to interpret the results and compare them with site conditions.

In designing solar power systems, it is important to minimize the gap between desktop simulations and on-site conditions as much as possible. For PCS selection as well, the more accurately you capture the actual roof shape, terrain, shading, orientation, tilt, cable routes, and installation space, the higher the evaluation accuracy in PVSyst. If you want to efficiently verify site location, elevation, and equipment layout, using the iPhone-mounted GNSS high-precision positioning device LRTK makes it easier to organize information from on-site surveys through design studies. To link PCS selection in PVSyst to decisions closer to real-world practice, it is essential to improve both understanding of the simulation and the accuracy of field data in tandem.