How to Do a Rough Design in PVSyst | 5 Steps to Summarize Quickly

Table of Contents

• Key considerations to decide first in a PVSyst preliminary design

• Step 1 Organize site conditions and the objectives of the study

• Step 2 Provisionally set meteorological data, orientation, and tilt

• Step 3 Roughly configure module capacity and array layout

• Step 4 Input loss conditions and shading effects to the minimum necessary

• Step 5 Confirm energy production and validity on the results screen

• Practical tips for completing a preliminary design quickly

• Points to note when moving from preliminary to detailed design

• Summary The more you account for site conditions, the higher the accuracy of the preliminary design

Key considerations that should be decided first in a PVSyst preliminary design

When performing a preliminary design in PVSyst, it is important to first clarify "what decision the estimate is intended to inform." There are multiple purposes in solar power generation design studies: the stage of estimating the expected system capacity, the stage of producing a guideline for expected generation, the stage of making an initial assessment of project feasibility, and the stage of creating comparative options to include in a proposal. If you open PVSyst with the purpose unclear, it becomes easy to be unsure how detailed the input settings should be, and a preliminary design that should be completed quickly will end up taking more time.

In preliminary design, it is not necessary to demand the same level of accuracy as in detailed design from the outset. Rather, it is important to distinguish and manage separately information that is confirmed at this stage and information that is assumed. For example, installation location, site area, roof shape, orientation, tilt angle, surrounding obstacles, assumed system capacity, module output range, assumptions for grid connection, and whether batteries are included all have varying degrees of certainty during the initial study. PVSyst allows many parameters to be set, but at the preliminary stage many items are treated as provisional assumptions to be replaced later.

To compile a summary quickly, first narrow the scope of the investigation. For example, for a preliminary estimate of a rooftop installation, initially focus on the orientation and tilt of each roof surface, the installable area, and the approximate number of modules. For ground-mounted installations, focus on the site shape, array spacing, the effects of earthworks and slopes, and nearby shading. For self-consumption projects, you need to consider not only the annual energy production but also the relationship with the demand curve; however, in the early stages it is sometimes acceptable to provisionally assume representative demand conditions.

PVSyst allows you to set input conditions in detail, but trying to enter everything precisely can be time-consuming. In preliminary design, the objective is to provide an estimate of energy production based on certain assumptions even when detailed equipment specifications or on-site survey results are not yet confirmed. Therefore, at the preliminary stage it is efficient to separate "conditions that significantly affect the results" from "conditions that can be adjusted later without materially changing the overall outcome."

Factors that particularly affect power generation are the site's meteorological conditions, azimuth (orientation), tilt, installed capacity, shading, temperature conditions, and loss conditions. Even a rough assessment of these factors lets you grasp the approximate annual energy production and generation efficiency needed in the early proposal stage. On the other hand, it is realistic to treat wiring length, minor equipment losses, and detailed obstacle geometries with standard values or simplified models during the estimation phase, and then revisit them when progressing to detailed design.

As deliverables of a preliminary design, it is desirable to have the annual energy production, system capacity, energy production per unit capacity, monthly generation trends, breakdown of major losses, and the assumptions of the design conditions organized. PVSyst results become more persuasive when shown not merely as numbers but together with the input conditions. In other words, for a preliminary design it is important to present not only “how many kW will fit” but also “under what conditions that figure was produced.”

Step 1 Organize site conditions and objectives of the study

Before starting a preliminary design in PVSyst, first clarify the site conditions and the objectives of the study. If this clarification is insufficient, even after proceeding with settings in PVSyst you are likely to have to go back later with comments such as “these conditions didn’t match the actual site” or “the proposal didn’t produce the necessary figures.” Preliminary design requires speed, but don’t skip the initial organization of conditions — doing so will ultimately allow you to finish in less time.

The first thing to confirm is the type of installation location. Whether it is rooftop, ground-mounted, a racking installation such as above a parking lot, for on-site consumption at a factory or warehouse, or a large-scale project for power generation, the items emphasized in a preliminary design will differ. For rooftops, the roof orientation, pitch, obstructions, and load limits are important. For ground-mounted systems, property boundaries, slope, site development conditions, array spacing, and shading from surrounding trees or buildings are important. For on-site consumption, not only the generation output but also the time-of-day overlap with power demand should be considered.

Next, decide which outputs you want to produce with PVSyst. Commonly requested at the preliminary estimation stage are an annual generation estimate, monthly generation, system capacity, assumed number of modules, the validity of the generation figures, and the main loss factors. When using this in a proposal, it is important not only to present the generation numbers but also to be able to concisely explain the underlying assumptions. For internal review, you may compare multiple options by keeping the same conditions and changing only the azimuth, tilt, or capacity to observe the results.

The minimum site information you should organize includes location, the area available for installation, orientation, tilt, surrounding obstacles, and the usable area. Location influences the selection of meteorological data. The area available for installation affects the maximum number of modules and the upper limit of capacity. Orientation and tilt directly determine how solar irradiance is received. Surrounding obstacles affect losses due to shading. Even if these items are unknown, preliminary design can proceed by making assumptions, but it is important to record those assumptions.

For example, at the stage before an on-site survey, you may make rough estimates using only drawings, aerial photographs, and basic site information. In this case, in PVSyst it is more practical to prioritize setting the orientation, tilt, and approximate capacity of the mounting surface rather than building a precise 3D model, and to treat shading simply by checking whether there are any major obstructions. Conversely, if on-site photos or survey data are available, you can bring the shading effects and the installable area closer to reality.

In preliminary design, it is better to adopt an approach of updating design conditions step by step rather than fixing them all at once. First, "check power generation with a provisional capacity," next, "adjust the capacity to match the installable area," and finally, "add shading and losses to make it more realistic." Following this order prevents spending too much time on inputs and makes it easier to grasp how the results change.

Also, in initial studies it is important not to assume overly optimistic conditions. If you base calculations only on conditions such as optimal orientation, no shading at all, and very small losses, the estimates may look good as rough figures but the actual power generation is likely to drop in later detailed design. In preliminary design, precisely because the numbers are used at the early proposal stage, making realistic, conservative assumptions builds trust.

Step 2 Tentatively set meteorological data and azimuth/tilt

When performing a preliminary design in PVSyst, the next settings are meteorological data, azimuth, and tilt. These three are fundamental conditions that greatly affect annual energy production. Even when producing a quick estimate, treating these roughly can cause the overall results to deviate significantly. Even without detailed on-site data, it is important to select meteorological conditions close to the installation site and to tentatively set the azimuth and tilt to realistic values.

Meteorological data are the fundamental information representing the solar resource at the installation site. In PVSyst, meteorological data are handled based on site information, but at the preliminary estimation stage you can begin assessments using data from nearby locations or standard meteorological datasets even if precise on‑site observational data are not available. However, caution is required in places where weather conditions can vary greatly over short distances—such as mountainous areas, coastal zones, regions with snowfall, fog-prone areas, and urban environments. When reviewing preliminary results, interpret them on the assumption that the selection of meteorological data has affected the estimated power generation.

Azimuth indicates the direction a solar panel faces. In preliminary design, a representative value is set according to the orientation of the roof surface or site. Panels closer to facing south tend to generate more electricity, but in practice the optimal azimuth cannot always be chosen solely because of roof shape, site layout, the timing of power demand, and constructability. Panels may be distributed across east- and west-facing roofs, or capacity may be prioritized within a limited site. Therefore, in preliminary estimates the orientation should be set based on what can actually be installed, and multiple azimuth options should be compared as needed.

The tilt angle is the parameter that indicates how much the module surface is inclined relative to the horizontal plane. For rooftop installations it is often matched to the roof pitch, while for ground-mounted systems a planned angle for the racking is provisionally set. The tilt angle affects not only annual energy yield but also seasonal generation patterns. Increasing the tilt can make panels receive more sunlight in winter, but installation spacing, wind loads, constructability, and shading effects must also be considered. At the conceptual stage, it is important to set a realistic angle according to the region and installation type and not to overly idealize it.

For using PVSyst, first set the project location, select the meteorological data to use, and then enter the system orientation and tilt. In preliminary design, it is more efficient to create one representative installation surface and add surfaces as needed while reviewing the results, rather than starting with a complex multi-surface configuration. For example, if the same roof has south-facing and east-facing surfaces, first estimate using only the south-facing surface, then add the east-facing surface and adjust the total capacity.

When temporarily setting orientation and tilt, it is also important to retain the basis for the input values. Whether the values were read from drawings, estimated from on-site photographs, or provisionally set as a typical roof slope will affect the confidence in the results. In proposal documents and internal memos, appending premises such as "orientation and tilt are approximate values" and "recalculation planned after on-site verification" will help prevent misunderstandings in later stages.

When preparing a quick preliminary design, prioritize consistency in meteorological data, azimuth, and tilt settings over perfection. When comparing multiple options, keep the meteorological data the same and change only the azimuth, tilt, and capacity, which makes differences in power output due to varying conditions easier to interpret. Changing one condition at a time makes it easier to identify which factors are affecting the results and simplifies explanations during proposals.

Step 3: Roughly estimate module capacity and configure the array

Once the meteorological conditions and the conditions of the installation surface are set, the next step is to establish the module capacity and the array configuration. In preliminary design, at this stage you decide “how much system capacity to install.” In detailed design you check equipment specifications, voltage ranges, circuit configurations, wiring, protective devices, and so on in detail, but at the preliminary stage the goal is to produce a realistic guideline for capacity based on the available installation area and the assumed module output.

The first thing to consider is the relationship between the installable area and the number of modules. For rooftop installations, the total roof area is not the same as the installable area. You need to take into account edge setbacks, inspection walkways, equipment, vents, skylights, lightning protection, shaded areas, and so on. For ground-mounted installations as well, the actual installable area is the area remaining after excluding site boundaries, access ways, slopes, drainage, maintenance routes, and array spacing. For a preliminary estimate, rather than filling these areas completely, estimate the number of modules based on an area that allows some margin.

In PVSyst you set equipment parameters corresponding to the modules and power conditioners and configure string and array layouts. What you need to watch in practice is not to ignore the consistency of the system configuration just because it is a rough estimate. If the number of modules or the series and parallel counts are unrealistic, it becomes difficult to use the result as a guide to expected generation. Even at the estimation stage, keep voltage ranges and capacity ratios from becoming extreme, and make the configuration such that you can proceed to actual equipment selection later—this will make the transition to detailed design smoother.

However, in preliminary design it may be better not to try to determine exact equipment model numbers. In initial proposals, it is preferable to assume module output ranges and typical capacity ranges for conversion equipment, prioritizing an understanding of the overall capacity and expected energy production. Final equipment selection will vary depending on inventory, procurement conditions, construction conditions, grid interconnection conditions, and design standards; therefore, at the estimate stage they should be treated as "representative configurations".

When roughly configuring an array, there are two methods: back-calculating from the target capacity, and building up from the number of modules that can be installed. At the proposal stage, if there is a target such as "we want to consider a system of approximately how many kW," you set a module count close to the target capacity and check whether that layout can be accommodated. Conversely, if there are strong site or roof constraints, you first estimate the number of modules that can be installed and then calculate the resulting system capacity. In practice, the latter approach is closer to reality, and especially for rooftops and small sites it is important to start from the installable area.

When using PVSyst results in an estimate document, make sure you can explain not only the system capacity but also the assumptions under which that capacity was set. For example: whether you excluded part of the installable area, avoided areas with strong shading, reserved space for future inspection walkways, or divided capacity by roof surface. Organizing this information prevents the generation figures from being taken out of context.

Also, in preliminary design, attention must be paid to the concept of oversizing. In solar power generation, adjusting the ratio between DC-side capacity and AC-side capacity affects energy yield and equipment utilization rate. At the preliminary stage, it is prudent to avoid extreme ratios and set them within a typical range. Increasing oversizing can raise annual energy production, but it can also increase output clipping and peak curtailment. PVSyst displays these as losses on the results screen, so even at the preliminary stage you should check that there is no major inconsistency.

Step 4 Enter loss conditions and shadow effects with the minimum required input

When performing a preliminary design in PVSyst, many engineers find configuring the loss parameters confusing. PVSyst includes various loss factors, but it is unnecessary to refine every factor in detail at the preliminary stage. What matters is entering realistic values for the representative losses that significantly affect energy production, and treating undetermined items as standard assumptions. Underestimating losses will lead to an overestimated energy production, while being overly conservative can reduce the viability of a proposal.

The losses to check first in a preliminary design are temperature loss, wiring loss, mismatch loss, soiling loss, conversion loss, and shading loss. Temperature loss is the effect of reduced output caused by an increase in module temperature. It can be more significant when rooftop ventilation is poor or in regions with high ambient temperatures. Wiring loss is the loss that occurs in DC and AC wiring. At the preliminary stage, wiring routes are often not yet finalized, so standard values are provisionally assigned and reviewed during detailed design.

Mismatch losses are losses that occur due to variations between modules and differences in solar irradiance conditions. In preliminary estimates they are often treated with standard settings, but if you adopt an unrealistic configuration — such as grouping surfaces with multiple orientations into the same circuit — the actual behavior may deviate. Soiling losses vary depending on sand and dust, pollen, bird droppings, contamination after snow, and the influence of the surrounding environment. At the estimation stage it is important to consider regional characteristics and cleaning schedules and not to use overly optimistic values.

The effects of shading require particular attention even in preliminary design. Shading not only significantly affects power generation but also influences monthly and time-of-day generation trends. On rooftops, adjacent buildings, rooftop penthouses, HVAC equipment, railings, chimneys, and antennas can cause shading. For ground-mounted installations, surrounding buildings, trees, utility poles, slopes, and adjacent array rows create shadows. Even if shading cannot be fully modeled in the early stages, be sure to check whether there are any major obstructions.

In PVSyst, you can model proximity shading conditions and include them in the simulation. However, modeling every complex 3D shape in a preliminary design is time-consuming. Therefore, when you need to prepare results quickly, a practical approach is to first simplify shadows from representative obstacles and from array spacing, and then examine in detail only the cases where shading is likely to be significant. If the presence or absence of shading greatly changes energy production, even at the preliminary stage compare both shaded and unshaded scenarios so you can explain the risk.

A practical point when inputting loss conditions is to organize the types of conditions rather than writing overly detailed justifications. Separating values into those that are fixed, assumed, or to be reviewed later will help prevent missed updates when progressing to detailed design. For example: treat temperature conditions as standard, wiring losses as assumed, shading conditions to be re-evaluated after on‑site verification, and soiling losses with consideration of regional characteristics.

Also, in the preliminary/approximate stage, you should avoid adjusting every loss in detail to force the calculated energy yield to match. Because PVSyst’s results change according to the input conditions, intentionally setting values to make the numbers look better will be difficult to justify later. In preliminary design, it is important to set realistic, explainable conditions and to evaluate the results honestly under those conditions.

Step 5 Confirm the generated power and its validity on the results screen

Once all inputs have been entered, run the simulation in PVSyst and check the energy production and its validity on the results screen. In preliminary design, it is important not to use the result figures as-is, but to verify that they fall within a reasonable range given the input conditions. If the annual energy production is too high or too low, the monthly trends look unnatural, or some losses are excessively large, there may be errors in the input conditions.

First, what you should look at is the annual energy generation. Check how much energy is produced annually relative to the system capacity, and determine whether it seems reasonable given the region and installation conditions. Next, review the monthly generation trends. In general, generation changes seasonally due to solar irradiance, temperature, and tilt angle. If a specific month is unusually low, re-examine whether there are issues with shading conditions, weather data, azimuth, tilt, snow cover, or loss settings.

The next thing to check is the power generation per unit of capacity. When comparing proposals with different installed capacities, it is difficult to make a judgment by looking only at the total annual generation. By checking the generation per unit capacity, you can compare how much each design generates per 1 kW. At the preliminary estimation stage, this metric makes it easier to grasp efficiency differences caused by orientation, tilt, shading, and loss conditions.

The breakdown of losses is also important. In PVSyst results, you can check at which stages and to what extent losses occur. If temperature losses are large, there may be room to review the installation configuration and ventilation conditions. If shading losses are large, it may be necessary to change the layout or reconsider the installation scope. If conversion losses or peak clipping are noticeable, you need to reconsider the ratio of DC-side capacity to AC-side capacity. In preliminary design, rather than optimizing every detail of losses, it is important to have the perspective of checking for any extreme anomalies.

When checking results, also verify consistency with the input conditions. For example, if you set a south-facing, low-shade condition but the energy production is extremely low, you may have entered the azimuth direction incorrectly. You may have meant to enter the roof tilt but it could be set to a value close to horizontal. The number of modules or the capacity settings may also differ from what you intended. When you are not yet familiar with PVSyst, you often discover input mistakes from a sense that the results are off, so post-calculation checks are essential.

When compiling a preliminary estimate document, organize the results together with the input conditions instead of presenting numbers alone. For example, present the installation location, installed capacity, orientation, tilt, main loss conditions, handling of shading, annual generation, and monthly generation trends so they can be explained in a single narrative. For internal reviews and customer proposals, it is not necessary to show all of the detailed settings screens, but making the assumptions clear increases the credibility of the preliminary results.

Also, in preliminary design, do not stop at a single calculation; create comparison options as needed. Comparing proposals such as one with slightly increased capacity, a different orientation, a different tilt, one that accounts for shading, or one that takes a conservative view of losses will broaden the range of proposals. However, because too many options make the documentation complex, it is easier to handle if you initially limit them to about two to three plans — a baseline plan and one or two adjustment plans.

Practical Tips for Quickly Compiling Preliminary Designs

To compile a preliminary design in PVSyst quickly, standardizing the workflow is more effective than the data-entry itself. Rather than starting from scratch each time, you can significantly reduce working time by deciding in advance the items to check per project, the parameters to use as assumptions, and the procedures for verifying results. Especially in practical work with many initial proposals, it is important not only to become familiar with operating PVSyst but also to have shared internal rules for preliminary estimates.

First, it is useful to prepare an input template for preliminary estimates. If you create a simple format to record installation location, purpose of study, installation type, orientation, tilt, system capacity, loss conditions, handling of shading, and output results, it becomes easier to work on PVSyst settings and proposal documentation in parallel. Because you can immediately record which conditions were used while reviewing the results calculated in PVSyst, the amount of rework when preparing documents later is reduced.

Next, it is also important to establish standard conditions. For example, internal rules such as how much loss to assume in preliminary estimates for rooftop installations, what array spacing to consider for ground-mounted installations, and how to handle shading when it has not been confirmed. This prevents large variations in preliminary results depending on the person in charge. Of course, conditions will vary by project, but simply having an initial baseline makes the work easier to proceed.

When creating comparison proposals, it is important not to change many conditions at once. For example, if you change capacity, orientation, tilt, and loss conditions simultaneously, it becomes difficult to determine which factor is causing the difference in energy output. To make quick decisions, create a single baseline proposal and then compare by changing only the capacity, only the tilt, or only the shading conditions from that baseline. This makes the results easier to explain and easier to reflect in proposal materials.

Also, in preliminary design one should focus on "the level of accuracy required for decision-making" rather than "fine precision." What is needed at the initial stage is not the level of accuracy of detailed construction drawings, but information to judge whether the project is worth pursuing, whether the intended installed capacity is reasonable, and what an approximate estimate of power generation would be. The goal is not to fill in every PVSyst configuration item, but to quickly extract the information necessary for decision-making.

On the other hand, precisely because it is compiled in a short time, you must be careful about input errors. Location, units, azimuth, tilt angle, capacity, number of modules, equipment configuration, shading settings, and the like can have a large impact on the results if entered incorrectly. In particular, misunderstanding the software’s definition of azimuth can lead to a design that faces the opposite direction from what was intended. Once the calculation results are available, always check the monthly generation and the breakdown of losses to confirm they fall within a reasonable range.

In time-constrained practical work, rather than putting PVSyst results directly into the final deliverable, you also need the ability to organize and communicate the key points. By succinctly summarizing energy production, system capacity, main assumptions, and caveats, it becomes easier for stakeholders outside the field to understand. Conversely, simply presenting large amounts of PVSyst screens and numbers makes it unclear what should be used to make decisions. In preliminary design, shaping the results in a form that makes it easy for the reader to make decisions is also an important responsibility of the design engineer.

Considerations when moving from preliminary estimates to detailed design

The preliminary design produced with PVSyst is intended only for initial assessments. As the project progresses, site investigations, surveying, detailed drawings, equipment specifications, grid interconnection requirements, construction conditions, and other factors will become clearer, so the input parameters must be reviewed. If the preliminary results are treated as definitive values for detailed design, discrepancies in energy yield, capacity, cost, and constructability may arise later.

When progressing to detailed design, the first thing to review is the available installation area. Even if a preliminary estimate assumed a relatively wide area could be used, the actual number of installable units can be reduced by inspection walkways, equipment clearances, structural constraints, legal restrictions, drainage, snow, wind, lightning protection, maintenance access routes, and other factors. Particularly on roofs, obstacles or deterioration not apparent from drawings may be found on site. For ground-mounted installations, the layout can change depending on slope, ground conditions, and whether site development is feasible.

Next, reassess the shading conditions. Obstacles that were overlooked during the preliminary stage can have a major impact on energy production when examined in detail. Shading is not simply a matter of being present or absent; its effects change with the time of day and season. You need to assess the impact on annual energy yield—for example, when shadows lengthen due to the low solar altitude in winter, or when adjacent buildings cast shadows in the morning and evening. By refining PVSyst’s near-shading settings, you can perform simulations that are closer to reality than those used in the preliminary estimate.

Equipment conditions will also be reviewed during detailed design. The modules and power conversion equipment parameters used in the preliminary estimate may differ from the equipment actually adopted. If output, electrical characteristics, temperature coefficients, input voltage range, conversion efficiency, or circuit configuration change, the PVSyst results will also change. Capacity ratios and string configurations that appeared acceptable during the estimation stage may need adjustment when applied to the actual equipment specifications.

Loss conditions will also be checked in more detail during detailed design. Once the wiring route is determined, wiring losses can be reviewed. Once the installation method is decided, temperature conditions can be re-evaluated. Once cleaning and maintenance policies are established, the approach to soiling losses can be clarified. In regions with heavy snowfall, salt-affected areas, or areas with high levels of dust, region-specific losses and maintenance conditions also need to be taken into account. Items treated as standard values during the preliminary estimate should be managed on the premise that they will be reconfirmed during detailed design.

In self-consumption projects, the accuracy of demand data is also important. At the preliminary estimate stage, you may evaluate annual consumption and representative load patterns, but in detailed design you need to verify time-of-day demand, differences between holidays and weekdays, seasonal variations, and equipment operating status. Even if generation is high, if demand and timing do not match, the self-consumption rate can be lower than expected. When using PVSyst, it is important to review not only the generation side but also the consumption-side conditions.

When moving from a preliminary estimate to detailed design, it is useful to keep a record of the history of assumptions. Organizing what was assumed in the initial estimate, what changed after the site survey, and which conditions were revised during detailed design makes it easier to explain changes in power generation. Even if the early proposal figures differ from the final design numbers, clearly explaining the reasons will make it easier to gain stakeholders' understanding.

Summary: The more site conditions are accounted for, the more accurate the preliminary design becomes

The method for carrying out a preliminary design in PVSyst is not to memorize all the complex operations from the start, but to quickly organize the conditions necessary for decision-making and realistically produce an estimate of energy generation. First, clarify the site conditions and the purpose of the study; next, set the meteorological data, azimuth, and tilt, and roughly configure the module capacity and array layout. Then input representative loss conditions and the effects of shading with the minimum required detail, and use the results screen to check annual generation, monthly generation, generation per unit capacity, and the breakdown of losses.

In preliminary design, it is important to distinguish which conditions are fixed and which are assumptions, rather than entering everything precisely. While PVSyst can perform detailed simulations, the results will be off if the input conditions deviate from reality. For that reason, even when preparing a quick summary, you need to check the consistency of basic conditions such as installation site, azimuth, tilt, shading, losses, and capacity.

Also, preliminary design is not something that is completed in a single pass. In practical work, the initial proposal is used to grasp the rough capacity and generation, and conditions are updated as on-site information increases. Once site investigations, surveying, detailed drawings, and equipment specifications are available, the input conditions in PVSyst can be made closer to reality. If the assumptions are carefully organized at the conceptual stage, the items to be revised when moving to detailed design will also become clear.

In particular, in solar power system design, it is important not only to consider desk-based input conditions but also how accurately you can understand the site's shape, obstacles, and available installation area. Roof edges, equipment and machinery, level differences, surrounding buildings, ground undulations, slopes, and existing structures all affect energy yield and constructability. Even if it is difficult to fully reflect these factors at the preliminary estimate stage, the sooner you capture site conditions, the closer PVSyst’s calculation results will be to real-world practice.

Therefore, to make preliminary designs using PVSyst more reliable, it is also important to have a system for efficiently acquiring on-site location and shape information. By utilizing LRTK, a high-precision GNSS positioning device that can be attached to an iPhone, you can obtain location data on site while easily recording the installation area and checkpoints. In preliminary design for photovoltaic systems, it is essential—before assessing energy yield in PVSyst—to understand where, over what area, and under what conditions installation is possible. By combining PVSyst simulations with on-site surveys using LRTK, even quick preliminary designs can more easily produce clear, explainable study materials that lead into the subsequent detailed design.