How to get started with PVSyst? 6-step initial setup flow

Table of Contents

• What is PVSyst?

• Step 1 Create a new project

• Step 2 Configure the project site

• Step 3 Select the meteorological data file

• Step 4 Configure the project settings

• Step 5 Define the first variant and system configuration

• Step 6 Run the simulation and check the results

• Common pitfalls in the initial setup

• Summary

What is PVSyst?

PVSyst is dedicated software for investigating photovoltaic power generation systems, sizing capacity, evaluating performance, and analyzing data. In the official documentation it is presented as an environment that can handle not only grid-connected systems but also off-grid systems, pumping applications, and DC-system applications, and is described as a comprehensive design and analysis tool equipped with a meteorological database, a component database, various solar energy–related tools, and functions for comparing measured data. In other words, it is not simply a calculator that produces annual generation once; it is easier to grasp the overall picture if you understand it as a practical platform for organizing a project's assumptions and handling the entire workflow from design to evaluation.

Another feature of PVSyst is that it allows you to connect initial estimates and detailed hourly simulations within the same conceptual framework. In the official project design guidance, it is explained that, for projects with geographic conditions and hourly meteorological data, multiple simulation runs can be compared as variants. This fits well with the practical workflow of not trying to get the design right in one shot, but creating a baseline design and then gradually changing conditions and adding losses and shading to converge on a reasonable design.

What beginners tend to find confusing at first is not the number of features, but the lack of clarity about where to start. In practice, PVSyst is not software where you should fill in settings at random. The official project definition shows the order to follow: first the project name, then the site, then the meteorological data file, followed by the project settings, and finally the variant definition. In other words, there is a proper sequence even for initial setup. This article organizes that sequence into six steps that are easy for beginners to follow and explains, from a practical perspective, where and what to check.

Step 1 Create a new project

The first step is to create a new project. In the official project definition, the first thing to do is define the file name and the project name. This is not just an input field; it is an important task that will determine how the case is organized, compared, and reviewed in the future. A project is the central management unit in PVSyst and functions as the foundation that holds geographic conditions and time-based meteorological data. If you do not build this foundation first, subsequent variant comparisons and the organization of results will not proceed as intended.

One reason you shouldn’t take this lightly in practice is that solar projects often spawn multiple variants later. When you have variants with different azimuths, different tilts, scenarios that assume losses more conservatively, or scenarios that include shading in greater detail, the number of calculation results with similar names increases and it quickly becomes unclear which one represents what. In PVSyst the structure is project-centered with variants hanging under each project, so if you organize things from the start so that the project name, target area, and intended use are clear, subsequent operation becomes much easier. Consider naming things in a way that won’t confuse you when you look back later as part of the initial setup.

When you're a beginner, you tend to want to "run some calculation first" and put off naming things. However, PVSyst is better used by building up assumptions for each project than by looking at one-off estimates on the spot. So it's easier to understand if you treat creating the initial project not as a mere task but as "the first step in creating the design record for this project." If you organize things carefully here, it will make a big difference later when you need to compare, explain, or revise.

Step 2 Set up the project site

The second step is to set up the project site. In the official project site description, the site provides the coordinates of the power plant, and the latitude and longitude are used to calculate the solar position at each time throughout the year. Furthermore, this site information is saved as a dedicated site file and is associated with the monthly weather data records used for simplified calculations as well as the search range for weather files. In other words, site configuration is not merely entering an address but becomes the starting point for all subsequent solar position and irradiance calculations.

What’s important here is that if the site location is set ambiguously, all subsequent calculations tend to become ambiguous. For solar power generation, results change even with the same installed capacity if the location differs, and if the site definition shifts, the irradiance conditions after applying azimuth and tilt will also shift. In PVSyst, site information is treated as the foundation of the project, so it is essential to clarify the coordinates that serve as the starting point for calculations. When comparing multiple candidate sites in practice, if this is not established first, later comparison results will be difficult to interpret.

The official guidance explains that site files also contain monthly weather data used for rough calculations. This information is useful in early-stage tasks such as orientation studies and system sizing estimates. In other words, a project site means more than "a single point on a map"; it also carries simplified regional conditions associated with the project. What beginners should understand first is that a project site is "the center of the project's location information," and it will serve as the reference for the weather data files and installation-condition standards chosen later.

Step 3 Choose the meteorological data file

The third step is selecting a meteorological data file. In the official project definition, the third stage is described as choosing a PVSyst-format weather file, and the weather database documentation also explains that it is possible to generate, visualize, and compare hourly data and to import external data. In other words, at this stage you decide the most fundamental premise: under what meteorological conditions this project will be assessed. Forecasts for photovoltaic power generation are affected by components and system configuration, but above all they are influenced by the weather conditions. Carefully choosing this is therefore extremely important during the initial setup.

What beginners often get stuck on here is thinking that choosing a single weather data file finishes the job. In reality, even for the same location there can be multiple files that differ by target year or by how they were prepared. Official comparisons of data sources explain that there are large differences among the available weather data sources, and it is not easy to determine precisely which is optimal or how large the errors are. In other words, selecting a weather data file is not merely a choice but an act of setting one of the design assumptions. For that reason, if multiple candidates exist, you should take an approach of comparing them as you make your selection.

Also, on the official page for available meteorological files, meteorological files for areas surrounding the currently selected site are listed, and you can use files made from built-in regional data, external data, or your own measured data. This means that PVSyst is not software that "just uses a single default dataset," but rather software that allows you to bring in appropriate meteorological assumptions depending on the nature of the project. It may look a little difficult for beginners, but conversely, it can be said that it makes it easier to design with proper consideration of meteorological conditions.

Also, when selecting a weather file, it is important not to assume that you should simply choose the one with the highest annual solar irradiation. Results also change depending on temperature conditions, hourly variability, and seasonality. Because PVSyst lets you view results by month, day, and hour later on, selecting the weather file is not merely a preliminary task but the entry point that influences the entire subsequent design decision process. If you handle this carelessly in the initial setup, no matter how thoroughly you refine the system configuration and losses later, the reliability of the results will be difficult to improve.

Step 4 Set up the project settings

The fourth step is to set up the project settings. On the official project settings page, the main additional parameters defined on this screen are listed as ground albedo, the reference temperature for array design, and several project-specific hidden parameters. In other words, this stage is not merely minor fine-tuning but a phase that establishes the baseline conditions which will affect later orientation analysis, array design, and evaluation of reflection conditions. It’s a screen that beginners tend to skip, but in reality it serves to consolidate the assumptions for the design.

What you should pay particular attention to here is ground reflectance. When ground conditions change, the way reflected components appear on the installation surface also changes, and depending on the installation environment this can produce differences in the results that cannot be ignored. Of course, there is no need to be excessively detailed from the very beginning, but simply having the recognition that “these assumptions are being managed here” will change how you read the results afterward. PVSyst is built on the design philosophy of organizing assumptions in the initial settings rather than being caught off guard after reviewing the results.

Also, the handling of the reference temperature is a point that’s easy to overlook. As the official documentation states, the project settings include a reference temperature for array design. Because solar power generation is strongly affected by temperature, simply knowing where the temperature assumptions are will change how convincing the results feel when you read them later. For beginners, a realistic approach is to first grasp the overall workflow using the default values, then return to this screen to review them according to site conditions and project characteristics. What matters for initial setup is not fully understanding this section, but recognizing that it is the place where important assumptions are gathered.

Step 5 Define the initial variant and system configuration

The fifth step is to define the initial variant and system configuration. The official project design tutorial recommends first defining a first system configuration with only the minimum parameters, letting PVsyst fill in the other conditions with reasonable default values, then running the initial calculation and saving it. Those minimum parameters include the orientation of the installation surface, the required output or available area, and the types of modules and power conversion equipment you want to use. In other words, the initial variant should be created not as a "complete version" but as a "baseline".

This way of thinking is very important for beginners. If you try to account for all losses and shading from the start, you’ll actually lose sight of the workflow. PVSyst is suited to a workflow where you first create a baseline scenario with minimal assumptions, and then sequentially make separate variants that add far shading, nearby shading, individual losses, and so on. In other words, in Step 5 the goal is not to “decide everything” but to “create the first reasonable starting point.” Understanding this makes the initial setup feel considerably less burdensome.

Also, in the official system definition, a grid-connected system is defined as the assembly of PV modules, strings, power conversion equipment, and the grid connection, and it states that components and configuration conditions should be defined for each subarray. In other words, this step is not simply about placing the installed capacity, but about deciding "what configuration will realize that capacity." After determining the orientation and tilt, configuring while checking the number of modules, the number of modules per string, and compatibility with the power conversion equipment makes it easier to reduce proposals that may look good on paper but are actually impractical.

Here is one more point to keep in mind. In the official explanation of shading and orientation matching, each orientation defined in a variant must be linked to an electrical sub-array in order to be simulated. In other words, orientation and the electrical configuration cannot be created separately—they must always be associated. A common pitfall for beginners is to feel they are finished after setting up the 3D model and orientations, but in PVSyst a design only becomes valid once it also matches the system configuration. Knowing this will make you less likely to be puzzled by errors or inconsistencies that appear later.

Step 6 Run the simulation and check the results

The sixth step is to run the simulation and review the results. According to PVSyst's official documentation, the results are said to include dozens of simulation variables and can be displayed monthly, daily, or hourly. The loss diagram is particularly useful for identifying weaknesses in the system design, and an engineering report that includes the main parameters and results for each simulation run can also be generated. In other words, running the simulation is a stage not only to "see the answers" but also to "check which parts of the design are effective."

What you must be sure to look at on the first run is not just the annual energy production figure. It is important to check the loss chart to see at which stages the energy incident on the plane of array is being lost. The official documentation also explains that the loss chart helps identify the main sources of loss. In other words, when the result is “lower than expected,” it becomes easier to distinguish whether that is due to irradiance conditions, temperature, shading, or the conversion side. If a beginner only looks at the annual energy production and stops there, they will not be using even half of PVSyst’s value.

Furthermore, the official detailed losses description recommends that, after the initial simulation, each loss factor be carefully defined to match the project. In other words, the first run is not an endpoint but the entry point to the next set of adjustments. If you think of it as an initial setup flow, step 6 should be considered not as “finish the calculation” but as “look at the initial results and decide what to refine next.” At this stage, it becomes easier to grasp that PVSyst is not software that gives a one‑shot answer, but software for developing a design by building up conditions.

Common pitfalls during initial setup

I have organized the flow into six steps so far, but there are points in the initial setup where beginners tend to stumble. First, they often confuse preliminary design with detailed design. PVSyst’s preliminary design is meant to quickly produce monthly estimates from a small number of general conditions, so its role is different from the definitive values of a detailed design. If you take the initial figures as the final values, you will likely be puzzled by the differences that appear when you later flesh out the details. The official guidance also recommends creating a baseline proposal first and then adding conditions sequentially.

Second, don’t treat databases or default values as absolute. Official system definitions and loss settings indicate that average defaults are used for the initial calculation, and that loss conditions should be reviewed later according to the project. In other words, default values are a “convenient starting point,” not “absolutely correct conditions.” In practice, it’s realistic to use defaults at first so you don’t stop the workflow, and then review them where necessary.

Third, don’t forget to link orientation and 3D information with the system configuration. The official documentation explains that a variant’s defined orientation must match the electrical sub-array in order to run a simulation. This means PVSyst does not treat "appearance" and "electrical system" separately. In initial setups you may not perform such deep 3D evaluations, but if you plan to move on to shading and detailed analyses later, it’s helpful to understand this consistency concept early to avoid confusion.

Summary

When organizing where to start with PVSyst, the workflow can be broadly summarized in six steps. First create a new project, then set the project site, choose the meteorological data file, configure the project settings, define the initial variant and system configuration, and finally run the simulation and review the results. The official workflow also places system definition and simulation after project definition, and it is recommended to first create a baseline case under minimal conditions, then add shading and losses in sequence. In other words, initial setup is not about "entering everything perfectly all at once" but about "reaching the baseline case without hesitation."

For practitioners, it's important not to think of PVSyst as software that provides a finished answer from the outset. The more you use it to grasp the overall picture with a small set of conditions—working through location and climate, orientation and layout, and then losses and shading in that order—the more valuable the software becomes. Understanding the initial setup flow makes it easier to see what is being decided on each screen, and it helps later readings of the results make sense. For beginners especially, it's recommended to firmly grasp just these six steps first.

The more carefully you fine-tune the initial settings in PVSyst at your desk, the more important the accuracy of on-site location information and equipment layout becomes. Even if you specify installation sites, orientation, and shadow assumptions in detail, if site surveying and obstacle identification are ambiguous in the field, discrepancies between design assumptions and construction reality tend to grow. That is why, at the design stage, preparing conditions in PVSyst and, at the site stage, combining that with an iPhone-mounted GNSS high-precision positioning device such as LRTK makes it easier to link design, construction, and operation & maintenance more consistently. The idea of keeping the initial settings consistent in PVSyst and aligning on-site positional accuracy with LRTK is well suited to improving the overall reproducibility of solar PV operations.