How to Set Up a New Project in PVSyst | 6 Quick Steps

Table of Contents

• Things to organize before starting a new project in PVSyst

• Step 1: Define the project's objectives and scope of study

• Step 2: Set project information and installation location

• Step 3: Check meteorological data and orientation and tilt conditions

• Step 4: Enter basic parameters for the solar panels and PCS

• Step 5: Configure layout, shading, and loss conditions

• Step 6: Run the simulation and review the results

• Common input mistakes and verification points for new projects

• Practical, easy-to-use procedures for managing projects in practice

• Summary: Accuracy of on-site information is crucial when launching new projects in PVSyst

Things to organize before starting a new project in PVSyst

When starting a new project in PVSyst, the first thing to be conscious of is not so much the screen operations themselves but how well the input conditions have been organized. PVSyst is simulation software for evaluating the power generation, losses, and system configuration of photovoltaic installations, but if you begin work with vague input values you will end up repeatedly going back to adjust settings. In actual practice, the candidate site location, installed capacity, panel orientation, tilt angle, PCS capacity, shading effects, and the way various losses are considered differ from project to project, so the initial organization directly affects the reliability of the results.

The purposes of launching a new project can be broadly categorized as preliminary estimates, design studies, preparation of proposal materials, power generation assessment, and pre-construction condition checks. For preliminary estimates, specific equipment models and precise layout drawings may not yet be decided. In such cases, a simulation is created using provisional conditions, proceeding on the assumption that these will be replaced with the formal conditions later. On the other hand, when the work is intended for design studies, internal approvals, or explanations to the client, it is necessary to clearly document the basis for the input conditions. Depending on which stage the project is in, the level of detail that should be set in PVSyst will vary.

A common stumbling block for beginners using PVSyst is the large number of input fields and uncertainty about the order in which to configure them. In reality, the workflow is not that complicated. First determine the project's purpose, set the installation site, choose the meteorological data, enter the azimuth and tilt, select the panels and PCS, adjust the layout, shading, and loss conditions, and finally run the simulation. If you standardize this workflow, setting up each new project will go smoothly.

This article explains how to create a new project in PVSyst in 6 steps so that practitioners can grasp the workflow as quickly as possible. Rather than covering every detailed specialist setting, it focuses on the thinking required to get a project established and to proceed to the initial simulation. It is useful not only for those using PVSyst for the first time but also for those who have been using it on their own and feel uncertain about the order of inputs.

Step 1: Define the project's objectives and scope of review

Before creating a new project in PVSyst, first clarify what the project is for. Depending on whether you want a rough estimate of energy production, to verify the appropriateness of the system capacity, to examine the balance between the number of panels and PCS capacity, or to evaluate the effects of shading, the level of detail you should input will vary. If you proceed with an unclear objective, you may spend excessive time on unnecessary details or, conversely, overlook important conditions.

For example, if you are still at the candidate land stage, an initial study can be conducted simply by entering tentative conditions for the installation location and approximate area, orientation, tilt, and equipment capacity. At this stage, it is more important to quickly compare multiple scenarios than to finalize the numbers. By using it to compare whether to orient east-west or primarily south-facing, whether to make the tilt shallow, or how much capacity to install, you can grasp the project's direction at an early stage.

However, when it is used for internal documents, proposal materials, loan reviews, or the preliminary stages of detailed design, the rationale for the input conditions must be provided. You need to be able to explain why you used those values for the installation location, meteorological conditions, equipment specifications, shading conditions, loss settings, and so on. PVSyst's results are useful, but the results alone do not allow you to judge their correctness. In practice, recording the assumptions under which the calculations were performed is extremely important.

When launching a new project, the way you name the project is also important. As the number of projects grows, similarly named projects can sit side by side and it becomes hard to tell which one is the latest. Including elements in the project name that indicate location, capacity, study stage, creation date, and differences in conditions makes them easier to manage. For example, for the same candidate site you might create proposals with different tilt angles, different PCS capacities, or different shading conditions. If project names or version names are not organized at that point, it will cause confusion when you compare them later.

It is also important to decide the scope of consideration at the outset. Whether the installation is ground-mounted or rooftop, on flat terrain or on a slope, and whether it has a single orientation or multiple orientations will change how you set things up in PVSyst. When dealing with complex terrain or roofs with multiple planes, trying to reproduce everything perfectly from the first attempt will make the work cumbersome. A realistic approach is to first produce a rough estimate using representative conditions and then refine it afterwards.

At the start of a new PVSyst project, rather than aiming for perfect inputs right away, it is important to quickly run a simulation with the level of accuracy appropriate to the project's objectives. Once you have results, you can see which conditions have the greatest impact on energy production and which items need to be refined. Therefore, in Step 1 you should begin by organizing the objectives, scope of study, project name, and the conditions you want to compare before entering the interface.

Step 2: Configure Project Information and Installation Location

The initial steps on the new-project screen in PVSyst are to enter the project information and set the installation location. The installation location forms the basis for the entire simulation because it affects the selection of meteorological data and the assessment of irradiance conditions, solar elevation, and azimuth. Even a small difference in location can change the trend of annual energy production, so it is important to specify a position as close as possible to the candidate site.

When entering the installation location, specify the point based on the address or the latitude and longitude. In practice, an address alone may not fully represent the exact site. Especially in mountainous areas, land development sites, large unused tracts, industrial parks, and land planned for conversion from agricultural use, the representative point of an address can differ from the actual installation area. Therefore, if possible, confirm the point using latitude and longitude and use a point close to the center of the site or to a representative installation location.

Project information includes basic details such as the project name, country or region, installation site, elevation, and time zone. Because elevation relates to weather and temperature conditions, enter a value as close as possible to the actual site. In power generation simulations, not only solar irradiance but also air temperature affect panel output. In high-temperature environments output tends to decrease, while in low-temperature environments output tends to increase. For this reason, consistency between the installation location and the meteorological conditions is important.

For new projects, first create the project at a single representative point, and then, as necessary, separate the conditions for further consideration. If the site is large and there are significant elevation differences north–south or east–west, or if shadow conditions vary greatly, representing the entire area with a single set of conditions may reduce accuracy. In such cases, it is necessary to take measures such as dividing the representative point into multiple locations, separating conditions by installation area, or checking shadow conditions separately.

One thing to keep in mind when using PVSyst is the concept of projects and variants. A project represents the overall scope of a case, and you can create multiple scenarios (variants) within it. For example, if you change the panel capacity, the orientation, or the loss conditions at the same installation site, you can manage each as a separate scenario. This makes it easier to compare multiple options while using the same site information and meteorological conditions.

At the outset of a new project, you should assume that conditions will change later. In solar power projects, land use plans, site development plans, grid interconnection conditions, equipment configurations, and construction methods may change partway through. Rather than rebuilding the project from scratch each time, adding alternative scenarios while keeping the original project makes it easier to track the change history.

After finishing the installation location settings, always verify that the point is the intended location. Especially for overseas or remote projects, you may accidentally select a place with a similar name. Even within Japan, the same place name can exist in multiple areas. If you set the wrong point during the initial setup stage, no matter how precisely you configure the equipment later, the results will be off. For new projects, it is important not to neglect confirming the location.

Step 3: Check meteorological data and orientation and tilt conditions

After setting the installation location, next check the meteorological data and the azimuth and tilt conditions. In PVSyst's energy production simulation, meteorological conditions such as solar irradiance, ambient temperature, and wind conditions have a large impact on the results. In particular, when evaluating annual energy production the results change depending on which meteorological data are adopted, so rather than simply using the data initially displayed you need to confirm that the data match the project's objectives.

Meteorological data can be based on observational measurements, satellite data, or prepared as long-term averages, among other approaches. In practice, the degree of precision required differs between using data for detailed feasibility assessments and for initial-stage rough estimates. For preliminary investigations, it is efficient to use representative meteorological data to obtain quick results and then compare with alternative datasets later as necessary.

Azimuth and tilt are fundamental conditions directly linked to energy production. Azimuth indicates which direction the panels face, and tilt indicates the angle at which they are installed relative to the ground or the mounting structure. Generally, setting the orientation and angle to receive sunlight efficiently tends to increase annual energy production, but in practice one must also consider land topography, racking design, wind load, snow, constructability, maintenance access, and the effects of nearby shading. Therefore, the optimal values in PVSyst do not necessarily translate directly into the optimal solution on site.

For new projects, we first set a single basic azimuth and tilt and compare multiple patterns as needed. For example, considerations include changing the tilt for a south-facing orientation, increasing capacity on east-west orientations, or setting different orientations for each roof surface. Because PVSyst can handle multiple surfaces and different orientation settings, even complex projects can have conditions added incrementally.

When entering azimuth and tilt, what you should pay attention to is whether the azimuth on the drawing matches the actual azimuth on site. If you enter values without confirming whether the drawing is referenced to true north, uses an arbitrary drawing orientation, or what the orientation of the coordinate system is, the panel orientation in the simulation may differ from reality. Confirming the on-site orientation is particularly important for undeveloped land and for the roofs of existing buildings.

Also, for projects on sloped terrain, avoid confusing the slope of the ground itself with the panel installation angle. The panel tilt is determined relative to the mounting structure or roof surface and may be considered separately from the terrain slope. When installing racking on sloped terrain, whether you follow the terrain, install at a fixed angle, or create stepped terraces will affect shading and inter-row spacing. Simplifications are acceptable for preliminary studies, but for detailed design, understanding the site topography is essential.

Meteorological data and orientation and tilt conditions are the foundation of a simulation. If these deviate significantly at this stage, even detailed adjustments to equipment settings and loss parameters later in the workflow will have difficulty producing results that reflect reality. When initiating a new PVSyst project, it is important to first verify the validity of the meteorological conditions and installation orientation, and to save the basic conditions in a format that makes later comparisons easy.

Step 4: Enter the basic conditions of the solar panels and PCS

Next, enter the basic specifications for the solar panels and PCS. When creating a new project in PVSyst, many people in charge spend the most time on this equipment configuration. Panel output, number of panels, string configuration, PCS capacity, input circuits, and the DC-to-AC capacity ratio affect not only the energy yield but also the feasibility of the system. You need to check not only matching capacities but also voltage ranges, temperature conditions, and the approach to oversizing.

When configuring solar panels, first check the basic specifications of the module to be used. The main items are nominal maximum power, open-circuit voltage, short-circuit current, voltage at maximum power, current at maximum power, temperature coefficients, and so on. In PVSyst you select or create the equipment data to set up, but in practice it is important to always cross-check with the datasheet. If there are similar model numbers or products with different outputs, selecting the wrong data can alter the simulation results.

When configuring the PCS, check the rated output, input voltage range, maximum input current, number of circuits, conversion efficiency, and so on. You need to verify that the number of solar panels in series falls within the PCS input voltage range and that the number of panels in parallel does not exceed the input current limit. In particular, because panel voltage rises at low temperatures and falls at high temperatures, it is important to ensure the configuration will operate safely and stably throughout the year.

An important point when using PVSyst is not to judge based solely on capacity. For example, the ratio between the DC-side panel capacity and the AC-side PCS capacity affects energy production and clipping losses. Increasing the DC side makes it easier to secure output during periods of low irradiance, but it can also cause output to be constrained at the PCS limit during periods of strong irradiance. How much of this to tolerate depends on the project's design policy and its business viability.

For the initial setup of a new project, it is efficient to first create a simulation with a standard configuration and then adjust the capacity ratio and string configuration afterward. If you try to perform detailed optimization from the very beginning, the number of input items increases and it becomes difficult to determine which change produced which result. First create a baseline plan, and then create scenarios that increase or decrease the number of panels, change the PCS capacity, and change the string configuration—this makes comparisons easier.

Equipment configurations should take future procurement changes into account. In the early stages of a new project, the final equipment model may not yet be decided. In such cases, it is practical to use a provisional configuration based on representative specifications and replace it later with the official specifications. However, if the provisional nature is not recorded in the project name or notes, it can later be mistaken for the final result. When using these details in proposal materials or internal briefings, it is important to clearly document and manage that they are provisional.

After entering the conditions for the solar panels and the PCS, check PVSyst for any errors or warnings. If there are inconsistencies such as voltage range, current range, capacity ratio, or number of inputs, the simulation itself may still run but the design may not be valid in practice. Rather than ignoring warnings and only looking at the results, confirm why the warnings are appearing and, if necessary, revise the configuration.

Step 5: Set layout, shading, and loss conditions

After entering the equipment parameters, configure the layout, shading, and loss conditions. When setting up a new project in PVSyst, this step is an important part of making the simulation realistic. Even with the same system capacity, power generation varies depending on panel arrangement, row spacing, surrounding obstacles, terrain, buildings, trees, and the racking layout. In particular, shading effects change with the time of day and season, so they should be checked carefully wherever possible.

In the layout settings, first determine how the panels will be arranged. For ground-mounted installations, check the row orientation, row spacing, number of racking tiers, maintenance aisles, and clearances from site boundaries. For rooftop installations, consider the roof orientation, tilt, usable area, surrounding equipment, lightning protection, and inspection walkways. Even if you cannot fully reproduce the site in PVSyst, it is important to prioritize entering the elements that are most likely to affect energy production.

Under shading conditions, we check whether surrounding buildings, mountains, trees, equipment, adjacent rows, and the like block sunlight. Shading not only reduces annual energy production but can also cause output variability depending on the time of day. At the low solar elevations of morning and evening, shadows from distant obstacles can extend, and during winter the impact of shading can be greater. In preliminary assessments it may be acceptable to proceed with simplified shading assumptions, but in detailed studies an evaluation that reflects the actual on-site conditions is important.

Inter-row shading is also an easily overlooked point. For ground-mounted and flat-roof installations, panels in the front row can cast shadows on the rear rows. Narrowing the inter-row distance makes it easier to increase installed capacity, but it can increase losses due to shading. Conversely, widening the inter-row distance reduces shading but may decrease the capacity that can be installed on the same site. PVSyst is useful for evaluating this balance between capacity and shading losses.

When setting loss conditions, consider temperature loss, wiring loss, mismatch loss, soiling loss, PCS conversion loss, aging degradation, availability, and so on. Beginners may feel that there are many loss items, but it is not always necessary to adjust all of them in detail. Depending on the stage of the project, it is important to decide whether to use standard values or values based on design conditions.

When setting losses, be careful not to use optimistic figures without justification. If losses are set too low, simulated power output will increase, but this can lead to a large discrepancy with actual performance. Conversely, applying overly conservative losses can make a project's evaluation unnecessarily strict. In practice, reasonable values are set based on internal standards, past projects, design conditions, and the site environment.

For a new project, it’s easiest to first create a baseline case using the standard losses, and then change conditions to analyze sensitivity. For example, compare how annual energy production changes when soiling losses are varied, when wiring losses are varied, or when shading conditions are varied. This reveals which risks are particularly important and where there is room for improvement in the project. PVSyst can be used not only to generate energy estimates but also to understand which conditions are affecting the results.

Layout, shading, and loss conditions are steps that are highly influenced by the accuracy of on-site information. If the conditions entered based only on drawings or desk-based assumptions differ from the actual site conditions, the reliability of the simulation results will decrease. In particular, it is desirable to organize items such as surrounding obstacles, terrain elevation differences, allowable installation area, and maintenance space based on on-site inspections and survey data.

Step 6: Run the simulation and check the results

Once you have finished entering the conditions, run the simulation. In PVSyst, based on the entered site location, meteorological data, orientation and tilt, system configuration, shading, and loss conditions, you can check annual energy production, various losses, and monthly generation trends. For the initial simulation of a new project, it is important not only to look at the numerical results but also to examine the relationship between the input conditions and the results.

The first things you should check in the simulation results are annual energy production, system utilization trends, monthly energy production, and the breakdown of major losses. Annual energy production is directly linked to the overall evaluation of the project, but you cannot judge its merit from that figure alone. By also checking which months have higher production, which losses are large, and how much impact shading and temperature have, you can assess the validity of the results.

On the results screen, checking the flow shown in the loss diagram makes it easier to grasp the overall picture. By tracing the flow from solar irradiance incident on the panel surface, through temperature, shading, mismatch, wiring, PCS conversion, and so on, to the final AC output, you can identify where generation is being lost. If any loss items are larger than expected, you should review the input conditions.

For example, if shading losses are large, check whether the layout and the settings for surrounding obstructions are appropriate. If temperature losses are large, check the installation environment, racking conditions, and meteorological data. If losses or output curtailment on the PCS side are large, review the DC-to-AC capacity ratio, PCS capacity, and string configuration. If wiring losses are large, check whether the assumed wiring length and cross-sectional area are realistic.

When launching a new PVSyst project, it is important not to consider the initial results as final. The first simulation is also a verification step to detect omissions or inconsistencies in the input conditions. If, after reviewing the results, you find the energy production is clearly too high or too low, the monthly trends are unnatural, or some losses are excessively large, go back and check the input conditions. Rather than stopping after producing results, you need an attitude of validating the input conditions based on the results.

Also, when producing a PVSyst report, I verify the assumptions listed in the report. I check that the installation site, meteorological data, equipment configuration, orientation, tilt, capacity, loss conditions, and so on are displayed correctly. For materials shared internally or externally, it is important to manage them in a way that makes the assumptions clear so that the numerical results are not taken out of context.

When comparing multiple options, avoid changing too many parameters at once. For example, changing azimuth, tilt, PCS capacity, and loss assumptions simultaneously makes it difficult to determine which factor is responsible for differences in power generation. The basic approach is to create a single baseline case and then produce derived cases with only a few targeted changes. This makes design decisions and explanations easier.

Common Input Errors and Verification Points for New Projects

When starting a new project in PVSyst, input errors occur not only among beginners but also among experienced users. Particularly common are errors in the installation location, incorrect azimuth input, misunderstandings of the tilt angle, incorrect selection of equipment models, inconsistencies in string configuration, forgetting to enter loss conditions, and oversimplifying shading conditions. Each of these may seem like a small mistake on its own, but they can have a significant impact on the results.

Mistakes in the installation site often occur during address searches or place-name selection. If you select a representative point that is far from the candidate site, or choose a different area with the same name, the weather conditions can differ. Because this is hard to detect in the early stages of a project, it is important to make a habit of checking the latitude and longitude and the location on a map.

Orientation input errors are also common. They arise from causes such as assuming the top of a drawing is north, confusing true north with magnetic north, or misunderstanding the azimuth reference. In PVSyst, understand the rules for entering orientation and verify that they are consistent with the on-site orientation and the drawings. This is especially important when there are multiple roof planes or in east-west layouts, as confusing orientations can have a large impact on the results.

Tilt angle is easily confused with roof pitch, racking angle, and terrain slope. For roof-mounted installations, the roof surface tilt may directly become the panel tilt, but the mounting rack can also change the angle. For ground-mounted installations, the ground slope and the panel surface tilt need to be considered separately. It is important to be clear which angle you are entering into PVSyst.

In equipment settings, it is possible to select the wrong specifications for panels or PCS. Choosing a different specification with a similar output, continuing to use an outdated specification, or using data with different temperature coefficients or voltage ranges can affect the results and the judgment of their validity. Equipment data is convenient, but in practice cross-checking against the specification sheet is indispensable.

Mistakes in loss conditions directly affect the results. While some projects can proceed using standard values, depending on the local environment you need to consider factors such as soiling, snow accumulation, shading, wiring, temperature, and operating rate individually. In particular, in mountainous areas, coastal locations, places with a lot of sand and dust, snowy regions, and high-temperature areas, assessing loss conditions based solely on general values can fail to reflect the actual conditions.

To prevent input errors, it is effective to standardize the verification flow for each project. Simply checking in the order of installation location, meteorological data, orientation, tilt, equipment, capacity, strings, shading, losses, and results can reduce oversights. When learning how to use PVSyst, it is more important to develop the habit of checking all items without omission than to speed up operations.

How to Manage Projects in a Practical, Easy-to-Use Way

When using PVSyst in professional practice, creating a single new project and calling it done is not sufficient. In many projects, design changes, capacity changes, equipment changes, layout changes, the addition of shading conditions, and revisions to loss conditions occur. For this reason, deciding on a project management method from the outset will make later work much easier.

First and foremost, it is important to define a clear baseline. Keep the conditions you initially created as the baseline and build change proposals from there, which makes comparisons easier. If you keep overwriting the baseline, you will lose the ability to revert to previous conditions and won’t know which changes altered the results. In practice, it is important not only to show the differences in outcomes but also to be able to explain the change history.

Next, establish rules for project names and version names. For example, using names that indicate the creation date, capacity, orientation, slope, and key changes makes it easier to understand the content when you review them later. This is especially important when multiple people are working; names that only the person responsible understands are not sufficient. If the names are made so that anyone can understand the differences in conditions, internal reviews and handovers will proceed more smoothly.

When sharing PVSyst results, be prepared to explain not only the report but also the key assumptions. Organizing items such as annual energy production, system capacity, azimuth, tilt, meteorological data, main losses, shading conditions, and equipment configuration makes it easier to verify the validity of the results. If you only provide the numbers from the report, the recipient may not understand the assumptions and misunderstandings can arise.

Also, it is important not to manage site information and PVSyst input conditions separately. Drawings, survey data, site photographs, obstacle information, available installation areas, and terrain information form the basis for simulations. If these items are managed separately, information consistency tends to break down when conditions change. Keeping PVSyst input values and on-site information in a verifiable, corresponding state improves the quality of practical work.

To streamline the launch of new projects, it's important not to start from scratch every time. By organizing commonly used loss conditions, standard input procedures, check points, naming rules, and report review items within the company, variation between personnel can be reduced. PVSyst is a high-functionality software, but because it offers a high degree of freedom, there tends to be variation in inputs between different users. It is important to standardize what can be standardized and to clarify the elements that should be adjusted for each project.

Furthermore, it becomes easier to make progress if you treat the initial assessment and the detailed assessment separately. In the initial assessment, grasp the rough capacity and energy output, while in the detailed assessment reflect site conditions and equipment specifications to improve accuracy. If you try to enter all detailed conditions from the start, work tends to stall due to insufficient information. Conversely, using the provisional assumptions from the initial assessment unchanged during the detailed assessment phase will result in insufficient accuracy. Using PVSyst according to the project stage is the key to applying it effectively in practice.

Summary: Accuracy of On-site Information Is Crucial for Launching New PVSyst Projects

The procedure for starting a new project in PVSyst proceeds by organizing the project's objectives, setting the installation site, checking the meteorological data and orientation and tilt, entering the conditions for the solar panels and PCS, configuring the layout, shading, and loss conditions, and finally reviewing the simulation results. If you follow these six steps, you can work on a project for the first time without losing sight of the overall picture.

What matters is not just memorizing how to operate PVSyst. It is understanding which conditions to input and how those conditions affect energy output. By proceeding while checking whether the installation location is misaligned, whether the azimuth and tilt match the actual site, whether the equipment configuration is valid, and whether shading and losses are being underestimated, you can improve the reliability of the simulation results.

In new projects, it can be difficult to assemble perfect conditions from the start. In such cases, it is effective to create a baseline proposal using provisional conditions and update it as information becomes available. However, it is important to manage project names, version names, and notes so that provisional and final conditions do not become mixed. Because PVSyst is well suited to comparing multiple proposals, creating alternative scenarios while keeping the baseline makes design decisions and explanations easier.

Moreover, accurate on-site information is indispensable for bringing PVSyst results closer to real-world practice. If the azimuth, tilt, site boundaries, obstructions, or terrain information set in the office differ from reality, no matter how meticulously you perform the simulation the results will be off. In solar PV projects in particular, site boundaries, panel layout, racking positions, surrounding shading, ground elevation, and the post-development shape of the land all affect energy yield and constructability. Accurately understanding the site and reflecting that information in PVSyst input conditions is the most direct way to improve the quality of energy yield assessments.

To streamline on-site position checks and simple surveying, you can use the LRTK, a GNSS high-precision positioning device that attaches to an iPhone, to more smoothly handle tasks such as locating candidate sites, checking near boundaries, geotagging on-site photos, understanding the installation area, and recording surrounding obstacles. Launching a new project in PVSyst is not something that can be completed solely through on-screen data entry; the extent to which you can incorporate accurate on-site information influences the results. By connecting the workflow from on-site verification to simulation, you can improve the evaluation accuracy and work efficiency of solar power projects.