6 Tips to Speed Up Project Evaluation Using the PVSyst Manual

Table of Contents

• Approach to Reading the PVSyst Manual as a Tool for Project Evaluation

• Tip 1: Decide in advance the scope to review in the initial assessment

• Tip 2 Gather meteorological data and site conditions early

• Tip 3: Formulate hypotheses about orientation, slope, and layout conditions

• Tip 4 Separate loss settings into standard values and project-specific values

• Tip 5 Fix the order in which you review result reports

• Tip 6: Leave decision notes that are easy to share internally

• Common points of confusion when evaluating projects using the PVSyst manual

• Operating patterns to be mindful of to speed up project review

• Summary

How to Read the PVSyst Manual as a Tool for Project Evaluation

The purpose of reading the PVSyst manual is not merely to memorize each operating procedure. To speed up the assessment of solar power projects, it is important to be clear about which screens to check and what to look for on each, which numerical values should be used as decision-making inputs, and how far to take the initial review. Simply reading the manual from beginning to end in order may not lead to the speed of judgment required in practical work.

In project evaluations, it is necessary to check multiple items in a short time, such as estimated power generation, site conditions, module layout, PCS capacity, shading effects, loss conditions, monthly generation trends, and the validity of simulation results. Therefore, it is important to use the PVSyst manual not only as a "dictionary" but also as a document that supports the "flow of project decision-making".

Especially in the initial stages, it is more important to quickly determine whether a project is likely to be viable, whether additional investigation is needed, or whether design conditions need to be revised, rather than perfecting every detail. When consulting the PVSyst manual, rather than digging into every feature, prioritizing the screens and settings that are directly related to project evaluation makes it easier to reduce rework in the review.

Also, PVSyst is software whose results are easily affected by differences in input conditions. Even small changes in meteorological data, azimuth, tilt, array spacing, obstructions, wiring losses, temperature losses, PCS settings, and so on can cause differences in annual energy production, PR, and monthly trends. For that reason, when consulting the manual you need to adopt the perspective of “which settings affect the results and in what way.”

When you want to speed up project assessments, the first thing to aim for is not speeding up operations but reducing points of uncertainty. Deciding in advance which inputs can be progressed with provisional values, which inputs should be entered only after checking supporting documentation, and which results you need to see before moving on to the next decision will greatly change the efficiency of using the PVSyst manual.

Tip 1: Decide in advance the scope to be examined during the initial review

One key tip for speeding up project assessment using the PVSyst manual is to decide in advance the scope to review in the initial evaluation. If you try to refine every setting in detail from the very first stage, the number of items to check becomes too large and it becomes difficult to make progress. First, clarify the scope needed for the initial decision, and prioritize reading the manual sections related to that scope.

The main items to confirm during the initial assessment are the power plant location, meteorological data, assumed capacity, azimuth and tilt, preliminary layout, effects of nearby shading and distant topography, major loss conditions, annual energy production, monthly energy production, PR, and so on. These directly affect the project's profitability and design policy, so they need to be understood at an early stage.

On the other hand, detailed equipment specifications, specific wiring conditions, precise obstruction modeling, and detailed comparisons of multiple cases can sometimes be deferred depending on the project stage. Of course, careful verification is necessary in the final design and proposal documents, but at the project outset, grasping the overall picture takes priority.

When reading the PVSyst manual, rather than trying to understand everything from the start, it is more efficient to decide in advance which chapters and sections are necessary for the initial assessment. For example, if you first grasp the workflow—project creation, meteorological data, system settings, array settings, loss settings, simulation results, and report output—you will find it easier to locate the items you need when they are required.

When there are many projects, if the scope of checks varies between the people responsible, it becomes difficult to compare the evaluation results. If one person configures shielding conditions in detail while another proceeds with standard values, it becomes hard to tell whether differences in the results are due to the project conditions or to differences in input policy. Aligning the scope of initial assessments is also important for improving the team's overall decision-making speed.

In preliminary assessments, the objective is to assemble the information necessary for decision-making in a short time, rather than to produce a perfect simulation in a single run. The PVSyst manual is effective for creating a verification workflow for that purpose. If you decide in advance how much to enter, how far to review the results, and which conditions to treat as provisional, you can reduce the time spent hesitating during project evaluation.

Tip 2: Gather meteorological data and site conditions early

The second tip is to align meteorological data and site conditions early on. In solar power generation simulations, the selection of meteorological data forms the foundation of the results. If conditions such as solar irradiance, temperature, latitude and longitude, elevation, and surrounding terrain are not appropriate, then no matter how detailed the subsequent settings are, the power generation forecast is likely to be inaccurate.

When consulting the PVSyst manual, you need to grasp not only how to import and select meteorological data but also the criteria for deciding which data should be used for a project. For example, it is important to check whether the data come from a location close to the project site, whether the solar irradiance trends do not deviate significantly from regional characteristics, and whether the elevation and temperature conditions are close to those on site.

In the early stages of project evaluation, precise design drawings and detailed equipment specifications may not yet be available. Even in such cases, site conditions and meteorological data should be organized as early as possible. If the meteorological data change later, annual and monthly power generation will need to be recalculated, which may alter the assumptions behind proposal materials and internal reviews.

Also, when comparing multiple candidate sites, it is important to select meteorological data using the same criteria. If you choose data using different approaches for each candidate site, the fairness of the comparison will be reduced. While referring to the PVSyst manual, decide within your company which data source will serve as the standard and how to adjust or make judgments when there is no data near a site; doing so will make it easier to proceed with project evaluations.

In site conditions, care must be taken to avoid input errors in latitude and longitude. Simple mistakes—digit errors, confusing east and west longitudes, north and south latitudes, or mixing degrees–minutes–seconds with decimal degrees—can affect power generation and solar position calculations. The more rushed a project is, the more important it is to go back to basics and verify the site inputs.

When it comes to terrain conditions, it is efficient to decide in the initial assessment to what extent they will be taken into account. If distant mountains or nearby structures clearly affect solar radiation, they should be included in the assessment early. Conversely, in the initial stage you can check whether there is any significant impact and defer detailed 3D settings to the next stage. Deciding the scope of inclusion at each project stage while referring to the PVSyst manual is the quickest way to reduce unnecessary work.

Tip 3 Organize hypotheses about orientation, slope, and layout conditions

The third tip is to organize the azimuth, tilt, and layout conditions as hypotheses before entering them into PVSyst. In project evaluations, the optimal layout changes depending on site shape, surrounding environment, mounting system, panel arrangement, and spacing conditions. If you fix one set of conditions from the start, it can cause significant rework when trying alternative proposals later.

When using the PVSyst manual, it is useful not only to check how to enter orientation and tilt, but also to understand the screens and setting items with the premise of comparing multiple conditions. For example, if you anticipate patterns in advance—options such as changing the tilt angle for a south-facing layout, arranging the system closer to an east–west orientation, slightly rotating the azimuth to fit the site, or widening versus tightening array spacing—you can assemble simulations more quickly.

In the early stages of a project, rather than producing a single optimal solution at once, it is effective to examine the sensitivity of power generation to changes in conditions. If you check how much the annual energy production changes when the tilt is altered slightly, how much loss occurs when the azimuth is aligned to the site, and how much the impact of proximity shading changes with array spacing, it becomes easier to make decisions on the design approach.

While reading the PVSyst manual, it is also important to be aware which layout-related settings are most likely to affect energy yield. Of course azimuth and tilt, but array spacing, ground reflection, shading/obstructions, string configuration, PCS capacity, and temperature conditions also influence the results. If you change everything at once, it becomes difficult to tell which condition affected the outcome, so when comparing you should limit the changes.

Also, to speed up project evaluations, it is useful to manage hypothesis names clearly. For example, if you include the intent of the analysis in the case name—such as Standard Option, Maximum Capacity Option, Shadow Impact Reduction Option, PCS Suppression Option, or Tilt Change Option—it will make it easier to judge when reviewing the results later. Even when handling multiple cases in PVSyst, organizing project names and variant names helps prevent confusion when sharing internally.

Layout conditions are also related to site conditions and construction constraints. Even a proposal that shows good energy production in PVSyst can in practice be difficult to construct, lack sufficient maintenance space, interfere with existing structures, or result in longer cable routes. When using the PVSyst manual, it is important not to rely solely on inputs in the software, but to make judgments while cross-checking drawings and on-site information.

Tip 4: Separate loss settings into standard values and project-specific values

The fourth tip is to separate loss settings into standard values and project-specific values. PVSyst provides many loss items that affect energy production. Temperature losses, wiring losses, mismatch losses, soiling losses, IAM, equipment characteristics, PCS losses, shading losses, and so on—the items to check vary by project.

When you rush project evaluations, trying to fine‑tune all loss settings will expand the amount of work time. Therefore, it is important to first distinguish between values used as internal standards and values that should be checked for each project. For example, if you separate items into those that use standard values in the initial review, those that must be revisited depending on project conditions, and those to be verified during the detailed design phase, the priorities for evaluation become clear.

When reading the PVSyst manual, check the meaning and scope of influence of each loss term. Rather than seeing them simply as numbers to enter on the screen, it is important to understand which physical phenomena or design conditions each loss represents. If you change values without understanding their meaning, the inputs will become mere adjustments to the energy production, and the basis for project decisions will be weakened.

Particular attention should be paid to duplicate loss settings. If a given effect is also accounted for under another item, the same loss may be counted twice. For example, shading, soiling, wiring, and equipment efficiency should be entered while confirming which documents or design assumptions they are reflected in. Reading the explanations in the PVSyst manual and organizing what each item actually calculates will make it easier to avoid overestimation or underestimation.

Also, loss settings are a part of the proposal materials that tend to attract questions. When explaining why annual power generation is high or low, if the basis for the loss conditions is unclear your explanation will lose credibility. To speed up project evaluation, it’s important not only to input data quickly but also to record the conditions in a way that’s easy to explain later. If you used standard values, note “company standard values,” and if you used project-specific values note “modified according to site conditions,” etc.; briefly recording the reasons for your decisions is recommended.

Reviewing loss settings becomes increasingly important as a project advances. In the initial study, proceed with rough estimates; before a proposal, review the major losses; and in detailed design, reconfirm them according to actual equipment specifications and construction conditions. Deciding the required level of accuracy for each stage makes the process more efficient. The PVSyst manual can be used as a reference standard to organize the verification items for each stage.

Tip 5: Fix the Order in Which You View Result Reports

The fifth tip is to standardize the order in which you review the results report. PVSyst simulation results contain a lot of information. Annual energy production, monthly energy production, PR, loss diagrams, system output, PCS-related results, irradiance, temperature effects, shading effects, and so on—because there are so many items to check, if the review order is not fixed it takes longer to reach a decision.

To speed up project evaluation, it's easiest to follow a flow of first checking the overall results, then looking at monthly trends, and finally examining the loss factors. If you only look at annual power generation, you're prone to making a simplistic judgment about a project's merits, but when you look month by month, more concrete issues become apparent, such as winter declines, temperature effects in summer, solar irradiance during the rainy season, and shading patterns.

When reading the PVSyst manual, it's important to check the meaning of each indicator that appears in the reports. PR is a metric often used to evaluate the performance of a power plant, but looking at the number alone is not sufficient. Because it varies with meteorological conditions, temperature conditions, loss settings, and system configuration, when comparing with other projects you also need to consider differences in input conditions.

Loss diagrams are particularly useful when evaluating projects. Because they allow you to visually confirm at which stages and to what extent losses are occurring, they make it easier to identify opportunities for improvement. For example, if shading losses are large, there may be room to reconsider the layout or array spacing. If temperature losses are large, it may be necessary to check installation conditions or module characteristics. If PCS-related losses are prominent, reviewing the capacity ratio or equipment selection should be considered.

Fixing the order in which results are checked can reduce oversights by the person in charge. If you decide to always view, in this order, annual energy production, monthly energy production, PR, major losses, shading effects, PCS-related items, and report conditions, the quality of checks for each project will be stabilized. By referring to the PVSyst manual and creating a verification order that fits your company’s project review process, internal reviews will also go more smoothly.

Also, when reviewing result reports, it is important to check the consistency between the input conditions and the results, not just the magnitudes of the numbers. For example, verify whether the report is not explaining based on an assumption of impact even though no obstructions were set, whether the orientation and tilt match the documentation, whether the PCS capacity aligns with the conditions under review, and whether the meteorological data correspond to the project location. A report is both a document for viewing results and a document for verifying input conditions.

Tip 6 Leave decision memos that are easy to share internally

The sixth tip is to leave decision memos that are easy to share internally. Even if you run simulations while referring to the PVSyst manual, if the reasoning behind the analysis isn't recorded, it takes time to explain the results later. To speed up project evaluations, it's important to adopt a practice of succinctly recording input conditions, changes, reasons for decisions, and the items to be checked next.

An assessment memo does not need to be long. Rather, being quick to read during a project review is important. Organizing which meteorological data was used, which azimuth and tilt were used for the calculations, which loss conditions were set to standard values, which items were set as project-specific values, why the power generation is lower than expected, and which conditions should be checked next makes it easier to share within the team.

When using the PVSyst manual, it’s helpful to keep a note of the items you consulted. For example, if you reviewed the shading settings, confirmed the approach to loss settings, or checked how to interpret the report’s PR—knowing which decisions you used the manual for will speed up future evaluations, because you can refer to past decision notes when similar projects arise.

A common problem in internal sharing is that only the simulation results are shared, so the input conditions and the reasoning behind the decisions are not clear. Looking only at the power generation figures, it is difficult to tell whether the results are conservative, optimistic, based on standard conditions, or reflect project-specific conditions. If there is a decision memo, the meaning of the results can be grasped in a short time.

Also, during project evaluations, people in multiple roles—sales, design, construction, management, and external partner companies—may look at the results. If you leave notes using only technical terms, their interpretation can vary depending on the reader. Using the item names from PVSyst while also adding their practical/operational meanings makes the shared documents easier to use.

The purpose of a decision memo is not to increase your work logs but to speed up the next decision. If you clarify the conditions that affected energy production, the conditions that remain uncertain, and the conditions likely to require recalculation, you will know where to start reviewing as the project progresses. The PVSyst manual is also useful for standardizing the items in such memos.

Common Confusions When Using the PVSyst Manual for Project Assessment

When advancing a project evaluation using the PVSyst manual, one common dilemma is how detailed the settings should be. If you get into too much detail during the initial assessment, it takes time. On the other hand, if you proceed with conditions that are too coarse, it can lead to major rework later. To strike the right balance, it is important to decide the required level of accuracy for each project stage.

For example, in the initial assessment you can estimate expected power generation from rough capacity and standard losses; before submitting a proposal you review orientation, tilt, major losses, and shading effects; and in detailed design you scrutinize equipment specifications, wiring conditions, and layout. By dividing the work into these stages, the range that needs to be checked in the manual is naturally narrowed.

Another uncertainty is the order in which to review items when the results don’t match expectations. When power output is low, you may be tempted to immediately change the loss settings, but the first things to check are the basic items: site, weather data, azimuth, tilt, capacity, equipment settings, and shading conditions. If the basic conditions are incorrect, adjusting loss settings will make it impossible to identify the root cause.

The PVSyst manual is also useful for checking the meaning of errors and warnings. However, when a warning appears, you should not immediately change settings; instead, you need to assess how much that warning will affect project decision-making. A point that may be acceptable in an initial assessment can become a problem that must be resolved before proposal or during detailed design.

Comparing multiple proposals can easily lead to confusion. If many conditions change between cases, it becomes unclear what is causing the difference in energy production. When comparing, it is important to narrow down the conditions you change at one time as much as possible, and to record the changes in the case names or decision notes. Reviewing the PVSyst manual and organizing your approach to the comparison functions and case management will speed up interpretation of the comparison results.

Also, you may be unsure whether the manual’s descriptions can be applied directly to practical work. The PVSyst manual helps you understand its operations and functions, but it does not specify every design decision or internal standard for each project. You should confirm the meaning of functions in the manual and determine how to use them according to your company’s project conditions and design standards.

Operational patterns to keep in mind to speed up project evaluation

To make effective use of the PVSyst manual in practice, it is important not only to have individual operational skills but also to establish standard workflows. If you verify everything from scratch for each project, work time and the quality of results will vary depending on the experience of the person in charge. By setting a standard procedure, it becomes easier to carry out analyses at a consistent quality even when the person in charge changes.

First, it is effective to decide in advance which input documents to check at the start of a project. Organize the information needed up front, such as location, site plan, candidate capacity, module options, PCS options, approach to orientation and tilt, surrounding obstructions, existing documents, and the policy on meteorological data. If materials are insufficient, determine whether to proceed with provisional assumptions or wait for confirmation.

Next, it is important to have standard conditions for initial assessments. If you have standard conditions, you can reduce the time spent hesitating on each project. However, even when using standard conditions, always review them when there are project-specific conditions. Standardization does not mean you do not need to think; it is intended to align the starting point for decision-making.

Furthermore, we will standardize the result verification checklist. In addition to annual energy production, we will create a workflow to check, in order, monthly energy production, PR, loss diagrams, input conditions, shading impacts, PCS-related items, and report output contents. By making this procedure the common format for project reviews, reviewers will be able to verify the contents in a short time.

The PVSyst manual can be used as foundational material for creating this operational template. You do not need to adopt the manual’s contents wholesale as internal rules, but it is important to understand the meaning of each item and the role of the settings screens, and then translate that understanding into verification procedures tailored to your company.

Having a standard operating pattern makes it easier to explain things to new hires and to colleagues in other departments. Teaching all of PVSyst’s functions at once to someone using it for the first time is difficult. However, if you organize the items to look at first during project assessment, the order of data entry, the sequence for checking results, and common mistakes, people can learn starting from the parts required for practical work.

What you most want to avoid when speeding up project evaluations is repeating the same uncertainties you had in past projects. If you find yourself agonizing over which meteorological data to use each time, hunting for the rationale behind loss settings every time, and rechecking how to read the results report every time, the burden grows as the number of projects increases. Referring to the PVSyst manual and accumulating commonly used decision criteria as in-house templates will lead to long-term efficiency gains.

Summary

To speed up project assessments using the PVSyst manual, it is important not only to learn how to operate the software but also to decide the order in which you will check the information needed to make project decisions. Decide in advance the scope to be reviewed in the initial assessment, assemble meteorological data and site conditions early, and organize orientation, tilt, and layout conditions as hypotheses to reduce rework.

Also, by separating loss settings into standard values and project-specific values, you can create simulations that are easier to explain while reducing the time required. It is important to fix the order in which the results report is reviewed, creating a flow to check annual generation, monthly generation, PR, loss diagrams, and the consistency of input conditions. Additionally, leaving decision notes will speed up internal sharing and checks during recalculation.

Because PVSyst is highly feature-rich, trying to understand everything at once takes time. However, if you prioritize reading the manual for the items necessary for project evaluation and organize verification procedures to match your workflow, the speed of assessment can be greatly improved. The important thing is to use the manual not merely as an operational guide but as a decision-making tool to quickly determine a project's viability.

Although conditions differ from project to project, the basic items to check are common. If you organize the workflow into site conditions, meteorological data, orientation and tilt, layout, loss settings, result reports, and decision notes, you can shorten the time from initial assessment to internal sharing. Incorporating the PVSyst manual into daily project evaluations and creating procedures that reduce uncertainty will lead to faster, more confident decisions on solar power projects.