6 Basics for Evaluating Self-Consumption Systems in the PVSyst Manual

Table of Contents

• The importance of reading the PVSyst Manual when evaluating self-consumption systems

• Basic 1: Clarify the project's prerequisites before creating the project

• Basic 2: Handle power consumption and load profiles carefully

• Basic 3: Bring meteorological data and installation conditions closer to actual on-site conditions

• Basic 4: Enter module, inverter, and loss settings accurately and completely

• Basic 5: Confirm the self-consumption rate, surplus power, and the effect on reducing purchased electricity

• Basic 6: Organize decision-making materials so they are easy to explain in report outputs

• Common mistakes in self-consumption simulations

• How to Apply the PVSyst Manual in Practical Work

• Summary

The importance of reading the PVSyst manual when evaluating self-consumption systems

When considering self-consumption solar PV, it is not enough to look only at whether the generated energy is large or small. You need to verify how much of the generated electricity can be used within the facility, at what times surplus power occurs, whether it leads to a reduction in purchased electricity, and whether the system capacity is excessive.

Therefore, the purpose of reading the PVSyst manual is not limited to learning the general操作 of generation simulations. It is important to understand the issues specific to self-consumption systems and to be able to explain the connection between input conditions and results.

PVSyst is simulation software used for designing photovoltaic systems and forecasting their energy production, but the reliability of the results is largely determined by how the input conditions are organized. For self-consumption systems, not only meteorological conditions and panel layout but also the handling of demand data is particularly important. Even with the same amount of generation, the share that can be self-consumed can differ greatly between a factory that uses a lot of power during the daytime and a facility whose power use is mainly at night. Therefore, when consulting the PVSyst manual, you should be aware not only of the sequence of screen operations but also which input items affect the evaluation of self-consumption.

Also, for self-consumption–oriented proposals, presenting only the generation figures can make it difficult to reach a decision. When judging whether to install equipment, it is necessary to explain annual generation, monthly generation, time-of-day surplus trends, self-consumption rate, the relationship with electricity consumption, grid interconnection conditions, future demand fluctuations, and so on, together. Rather than simply looking at the PVSyst report as-is, understanding which items should be explained to the client and internal stakeholders leads to practical application.

This article organizes six key basics to keep in mind when considering self-consumption solar power, with reference to the PVSyst manual. We sequentially explain practical points that often cause confusion in real-world work — input conditions that beginners tend to trip up on, how to think about load data, system design, loss settings, checking results, and making use of reports.

Basic 1: Organize the project's prerequisites before creating the project

Before starting an evaluation of a self-consumption project in PVSyst, it is important to first organize the project's assumptions. If you open the software and immediately create a project, you may later notice missing or overlooked conditions, requiring re-entry or re-simulation. For self-consumption projects, the installation site, building use, power contract, demand patterns, roof and site constraints, and the treatment of surplus power all directly affect the results. When reading the PVSyst manual, rather than simply following how to use the project creation screen, you should take the perspective of confirming what needs to be decided before entering data.

The first thing to clarify is what type of facility is being considered. Factories, warehouses, logistics facilities, commercial facilities, schools, hospitals, office buildings, etc., have different patterns of electricity use by time of day. If a facility’s operations are concentrated during weekday daytime, it may be well suited to solar PV, but if operations are mainly on holidays or at night, consideration of surplus power and battery storage may be necessary. In PVSyst, even if you input the same solar PV system, the assessment of self-consumption can change significantly when load conditions differ.

Next, confirm the conditions of the planned installation site. Location, latitude and longitude, elevation, surrounding shading, orientation of roof surfaces, tilt angle, usable area, and structural constraints all affect power output. In particular, for rooftop installations, the roof may have multiple orientations, and there may be shadows from equipment or parapets. If these factors are oversimplified, simulations may show good results but can lead to discrepancies with actual power generation and self-consumption benefits.

In self-consumption systems, the primary objective is to use the generated electricity within the facility. Therefore, unlike projects that assume power sales, it is necessary not only to pursue maximum generation but also to confirm whether the system capacity is appropriate for the demand. Increasing system capacity will raise annual generation, but if a large surplus occurs during periods of low demand, the self-consumption rate will decrease. Conversely, if system capacity is reduced too much, the reduction in purchased electricity may not be sufficient. To check this balance, it is important to organize the assumptions so that multiple scenarios can be compared in PVSyst.

Also, the objective of the study should be made clear from the start. Whether the work is a preliminary proposal, an internal approval document, material for financial institutions or investment decisions, or an analysis approaching detailed design will change the required accuracy and the granularity of explanations. In the rough-estimate stage you may use assumed values, but in that case you must explicitly state that they are assumptions and make sure they can later be replaced with measured data. Even when working while consulting the PVSyst manual, clearly distinguishing which inputs are assumptions and which are measured or confirmed information will make later revisions in downstream processes easier.

Basic 2: Handle power consumption and load profiles carefully

One of the most important elements in self-consumption solar PV simulations is the facility’s power consumption and load profile. When you proceed with settings using the PVSyst manual, it’s easy to focus on the generation-side conditions, but for self-consumption systems the demand-side data largely determines the credibility of the results. No matter how much the solar PV generates, if the facility isn’t using electricity at that time it won’t contribute to self-consumption. Therefore it’s important to make not only the annual consumption but also the monthly, day-of-week, and hourly usage patterns as realistic as possible.

Ideally, use time-series data such as 30-minute values or 1-hour values. If you have utility meter data or data from demand monitoring devices, it becomes easier to reflect the facility’s actual load variations. For example, even facilities with the same annual electricity consumption will have different self-consumption rates if one uses electricity steadily during the daytime and another has peaks in the morning and evening. When examining a self-consumption scenario in PVSyst, the lower the resolution of the load data, the more difficult it is to accurately grasp surpluses and shortages for each time period.

If time-series data are not available, you will need to estimate load patterns from monthly usage and the facility's operating hours. In this case, care must be taken in how assumptions are made. For facilities whose operations differ greatly between weekdays and holidays, facilities whose HVAC load varies seasonally, or facilities with fluctuations in production equipment operation, using a simple average can diverge from the actual situation. It is advisable to check the sections of the PVSyst manual on load settings to understand what formats demand data can be entered in and how finely conditions can be reflected.

When dealing with load profiles, you should check the base load as well as peak demand. In self-consumption setups, the more a facility has a continuous daytime base load, the easier it is to utilize solar power generation on-site. For example, if refrigeration equipment, air conditioning, pumps, compressors, or information and communications equipment operate continuously during the day, they may be able to consistently absorb a certain amount of generation. On the other hand, in facilities that experience large peaks only for short periods, sizing equipment capacity to match the peak can lead to increased surplus during other times.

Also, the treatment of holidays is important. In factories and offices, there is a high load on weekdays while power consumption can drop significantly on holidays. Since solar PV generates electricity on holidays as well, surplus power tends to occur when demand is low. If holiday loads are overstated to make the self-consumption rate look higher, surpluses may increase during actual operation and the expected benefits may not be achieved. For the load conditions entered into PVSyst, it is important to keep the rationale so you can explain it to stakeholders later.

When handling demand data, consider future changes. Equipment expansions, changes in operating hours, HVAC upgrades, the introduction of EV chargers, the addition of storage batteries, business expansion, and so on mean that current electricity usage patterns may not continue in the future. In early-stage simulations, use current data as a baseline while also examining alternative cases in which future demand increases or decreases; this widens the range of options when deciding on implementation. When using the PVSyst manual, it is important not to rely on a single result but to compare multiple scenarios with varying conditions.

Basic 3: Align meteorological data and installation conditions with local conditions

When calculating energy production with PVSyst, meteorological data and installation conditions are the absolute basics. Even for self-consumption systems, if the accuracy on the generation side is insufficient, evaluations of the self-consumption rate and reductions in purchased electricity become difficult to trust. The PVSyst manual covers items such as selecting and importing meteorological data, site settings, tilt angle, and azimuth, but in practice what matters is "which data to use" and "how much of the site conditions to reflect."

First, it is fundamental to choose meteorological data that are close to the installation site. Solar irradiance, air temperature, wind speed, and other parameters vary by region. In particular, in mountainous areas, coastal zones, snowy regions, fog-prone areas, and urban environments, data from nearby locations can still differ from actual conditions. When selecting meteorological data available in PVSyst, it is important not to simply pick a site because it is listed as a candidate, but to verify that it matches the local climatic characteristics.

Next are the settings for azimuth and tilt angles. For self-consumption systems, a layout that maximizes annual energy generation is not necessarily optimal. For example, east-facing generation can be effective at facilities with high morning demand, and west-facing generation may be considered at facilities with remaining demand in the evening. By comparing not only a south-facing option that maximizes annual generation but also layout options tailored to the demand time periods, you can get closer to the optimal solution for self-consumption. Referring to the PVSyst manual and preparing to handle multiple subarrays and surfaces with different orientations makes it easier to evaluate layouts that match the roof geometry.

The impact of shadows is also important. In self-consumption projects, systems are often installed on rooftops, and air-conditioning outdoor units, cubicles, chimneys, parapets, adjacent buildings, signage, trees, and so on can cast shadows. Losses from shading affect not only total generation but also the time-of-day generation pattern. For example, if shading occurs in the morning, the generation contribution to morning demand may decrease. When performing shading analysis in PVSyst, check the creation of the 3D scene and the near shading settings, and be careful not to oversimplify.

The available installation area and layout constraints also affect the amount of power generated. You cannot always cover the entire roof with panels; you must consider inspection walkways, fire compartments, clearances around equipment, structural load limits, maintenance spaces, and so on. Creating an ideal layout in PVSyst is pointless if that layout cannot be constructed in practice. A rough layout is acceptable in the early stages of study, but as the design progresses it is necessary to bring it closer to the actual roof plans and layout drawings.

Temperature conditions must not be overlooked. Solar modules lose output when they get hot. At facilities where roof surface temperatures tend to rise in summer, temperature-related losses will affect energy production. For self-consumption systems, cooling demand often coincides with generation in summer, so it is important not to overestimate summer generation. Check the temperature model and mounting-configuration settings in the PVSyst manual, and choose realistic conditions according to rooftop or ground-mounted installation and ventilation conditions.

In snowy regions, reduced power generation in winter should also be taken into account. Snow-induced shading, tilt angle, snow-shedding conditions, and whether snow removal is performed can cause large variations in winter generation. When evaluating the annual impact of introducing self-consumption systems, facilities with high winter demand may experience that snow-related generation declines affect the reduction in purchased electricity. Rather than judging solely by PVSyst’s standard settings, adjustments or separate assessments based on regional characteristics may be necessary.

Basic 4: Enter module, inverter, and loss settings accurately and completely

When using the PVSyst manual, many people check the module and inverter settings. If the basic configuration of the photovoltaic system is not entered correctly, discrepancies will arise in the calculated generation and losses. For self-consumption systems, module and inverter capacity settings are particularly important, since you must consider not only the amount of generation itself but also the balance between system capacity and demand.

In the module settings, confirm the rated output, temperature coefficients, and voltage and current characteristics of the PV modules to be used. Even if PVSyst’s database contains the corresponding model, you must verify that the model number and specifications match the latest ones. Choosing a similar model number by mistake can lead to differences in output and electrical characteristics. If the final module choice has not yet been decided, it is advisable to assume representative specifications for analysis and proceed on the premise of later replacing them with the finalized model.

In inverter settings, check the capacity ratio, input circuits, MPPT, voltage range, and the approach to oversizing. In self-consumption systems, how much of the generation peak the inverter accepts affects the results. If the inverter capacity is made smaller relative to the panel capacity, clipping may occur at peak times, but from the perspective of equipment cost and operating hours this can be reasonable. Conversely, if the inverter capacity is too large, it may be disadvantageous in terms of equipment cost and efficiency at low loads. In PVSyst, it is important to check to what extent inverter losses and limitations occur and not to judge solely by annual energy production.

In the loss settings, check wiring losses, mismatch losses, soiling losses, degradation, shading losses, temperature losses, conversion losses, and so on. When setting each loss item while consulting the PVSyst manual, do not simply use the initial values; consider whether they fit the project's conditions. In environments with heavy dust on rooftops, coastal locations where salt damage is a concern, or areas near farmland or factories where soiling tends to occur, the assessment of soiling losses changes. If wiring distances are long or the power conditioner is installed far away, wiring losses cannot be ignored.

In self-consumption systems, the handling of output control and reverse-flow restrictions must also be considered. Depending on whether surplus power can be sold, the design forbids reverse flow, or control is implemented to suppress surplus, the treatment of generated power changes. If the power that could be generated exceeds demand and cannot be sent to the grid, output will be curtailed. In that case, although the annual generation figure alone may make the system capacity look high, the amount of energy actually available for use may be smaller. It is necessary to check how PVSyst handles limits and surplus and to align that with the project’s grid conditions.

When combining a battery storage system, the settings become even more complex. Using a battery can potentially shift daytime surplus power to the evening or night, but the effectiveness varies depending on capacity, charge/discharge efficiency, control strategy, degradation, and discharge timing. Even if a battery is installed to increase the self-consumption rate, it does not necessarily mean that all surplus will be used effectively. When modelling batteries in PVSyst, it is important to compare the PV-only scenario with the PV-plus-battery scenario to confirm how much surplus reduction and reduction in grid purchases can be achieved.

Basic 5: Confirm self-consumption rate, surplus power, and reduction in purchased electricity

In evaluating self-consumption systems, the most important consideration is how much of the generated electricity can be used within the facility. When checking the results screen while reading the PVSyst manual, you need to confirm not only the annual energy production but also the self-consumption rate, the surplus electricity amount, the reduction in purchased electricity, and solar's contribution to demand. Explaining only the amount of energy generated without understanding these figures will not correctly convey the effectiveness of introducing a self-consumption system.

The self-consumption rate is a concept that indicates the proportion of generated electricity that is consumed within the facility. A higher self-consumption rate can be seen as meaning the generated electricity is being used without waste. However, a high self-consumption rate alone is not necessarily good. If system capacity is made extremely small, most of the generated electricity can be used within the facility, so the self-consumption rate will be high, but the reduction in purchased electricity may be small. Conversely, if system capacity is increased, generation will rise, but the periods when generation exceeds demand will also increase, and the self-consumption rate may fall. Therefore, it is important to consider the self-consumption rate together with generation and the reduction in purchased electricity.

Checking surplus power is also essential. By understanding in which months, which days of the week, and which time periods surplus power occurs, you can reassess equipment capacity and determine the need for battery storage. For example, if there is a lot of surplus during daytime on holidays, consider whether holiday loads are expected to increase, whether surplus power can be sold, or whether output control can be accepted. If surplus is concentrated on sunny days in summer, reducing equipment capacity slightly may improve investment efficiency. When reviewing PVSyst results, it's important to look not only at the annual totals but also at trends by time of day.

The reduction in purchased electricity is an important indicator that leads to lower electricity bills. However, PVSyst’s simulation results mainly show generation and energy flows, and detailed evaluations of contract unit prices or demand charges may need to be handled separately. Even if self-consumption reduces the amount of purchased electricity, the effect on reducing the basic charge can be limited unless the maximum demand decreases. Conversely, if solar PV contributes during peak hours, it may help suppress demand. When linking PVSyst results to electricity bill reductions, it is easier to explain by separating energy charges (per kWh) and basic charges (fixed charges).

When comparing installed capacities, it is useful to create multiple scenarios. For example, comparing options such as maximizing rooftop installation, reducing capacity to match demand, limiting reverse power flow, and combining with batteries reveals characteristics that are not apparent from a single option. Options with a high self-consumption rate, high annual generation, low surplus, and good investment efficiency do not necessarily coincide. It is advisable to organize the project in a way that makes comparison easy while checking the PVSyst manual for how to handle variants and change conditions.

Also, check the relationship between monthly power generation and demand. Solar power generation varies by season, and a facility’s electricity consumption also fluctuates seasonally. For facilities with high air-conditioning demand, electricity use increases in summer, so they may pair well with solar generation. Conversely, for facilities with high winter demand, reduced sunlight and the effects of snowfall can make the expected reduction in purchased electricity smaller. Even if the annual total looks sufficient, examining seasonal breakdowns can reveal issues.

When reading the results of self-consumption simulations, interpret them in conjunction with facility operations rather than evaluating the numbers in isolation. Instead of making simple judgments such as “excess is bad” or “low generation is bad,” consider whether the results are appropriate for the project’s objectives. The optimal design changes depending on whether you prioritize securing environmental value, reducing electricity costs, including BCP measures, or anticipating future electrification demand. PVSyst’s results are material for decision-making, and alignment with business objectives is essential for the final decision.

Basic 6: Organize decision-making materials to be easy to explain in report output

PVSyst simulations are not finished simply by entering data and viewing the results. In self-consumption projects, it is necessary to share the results in various situations, such as internal briefings, explanations to the owner, explanations to financial institutions, and consultations with the design team. Therefore, it is important to understand how to read the report outputs by referring to the PVSyst manual and to organize them into clear, easy-to-explain decision materials.

In a report, first confirm that the assumptions are correctly stated. The installation location, meteorological data, system capacity, modules, inverters, tilt angle, azimuth, loss conditions, and so on need to match the scope of the study. Even if the figures in the report are correct, credibility decreases if the assumptions cannot be explained. Especially for self-consumption systems, load conditions and the handling of surplus power become important, so it is advisable to separately document which demand data was used, what period the data covers, and whether any assumed values are included.

Next, we review the results for annual generation, monthly generation, loss diagrams, performance ratio, and self-consumption. Loss diagrams are helpful for explaining where and to what extent losses occur. By checking whether temperature losses are large, shading losses are large, or inverter losses are notable, you can identify directions for design improvements. In self-consumption–oriented proposals, it is more persuasive to explain, rather than simply stating "this much will be generated annually," that "under these conditions surpluses tend to occur during these time periods, and adjusting system capacity can improve the self-consumption rate."

When using reports, it is also important not to confuse simulation results with economic evaluations. PVSyst results provide the basis for estimates of energy production and energy flows, but savings on electricity bills, payback periods, subsidies, maintenance costs, taxes, and contract terms may require separate calculations. Rather than using PVSyst figures directly for monetary assessments, combine them with electricity unit prices and contract terms and organize the results separately to improve the accuracy of explanations.

In materials for stakeholders, comparing multiple options is important. Comparing scenarios such as the maximum-installation option, the demand-following option, the surplus-suppression option, and the battery-combined option, and organizing each one’s advantages and points to note makes decision-making easier. Because simply outputting multiple PVSyst reports can sometimes make comparison difficult, it can also be effective to summarize the key results in a separate document. Possible comparison items include installed capacity, annual power generation, self-consumed energy, surplus energy, self-consumption rate, reduction in purchased electricity, and major loss factors.

Also, because the report includes assumptions used in the simulation, it is necessary to explain that it does not guarantee actual measured values. Solar irradiance varies from year to year, and a facility’s power consumption also changes with operational conditions. Power generation also fluctuates due to soiling, failures, maintenance status, and changes in the surrounding environment. Handling the report with an understanding of the PVSyst manual means not simply producing numbers, but being able to explain the assumptions and limitations behind those numbers.

Common Mistakes in Self-Consumption Simulations

A common mistake when evaluating self-consumption systems in PVSyst is to focus solely on generation and treat the demand data lightly. For plants that sell power to the grid, annual energy yield and performance ratio are the main concerns, but for self-consumption systems the overlap with demand is crucial. If you run simulations with coarse demand data, it can appear that energy can be self-consumed even though in reality there is a large surplus.

A common mistake is determining system capacity based solely on roof area. Installing as many panels as will fit on the roof will increase generation, but if the number of hours when generation exceeds facility demand rises, the self-consumption rate will fall. If selling excess power is possible, there is some value in that, but if there are reverse power flow limits or the value of surplus power is low, the system can become oversized. For self-consumption systems, it is necessary to balance roof area, demand, grid conditions, and investment objectives.

Be careful not to rely too heavily on the default loss settings. Defaults are convenient as a starting point for consideration, but they may not match actual on-site conditions. Shading, soiling, temperature, wiring, inverter limitations, and similar factors vary from project to project. In particular, for rooftop installations the effects of shading from nearby equipment and of ventilation conditions are often pronounced, so it is important to review the settings together with on-site surveys and drawing checks.

A period of load data that is too short can also lead to failure. Using only a few days or data from a single month may not accurately reflect annual trends. For facilities where load varies between busy and slow seasons, summer and winter, and weekdays and holidays, you should use as long a period of data as possible. If you absolutely only have short-term data, explicitly state that many assumptions were made and proceed on the premise that the data will be updated later, which is safer.

When explaining results, you should avoid simply listing technical terms. PVSyst reports contain many technical items, but the project owner or internal decision-makers may not understand them all. It is necessary to clearly explain the items that affect decision-making, such as self-consumption rate, surplus power, reductions in purchased electricity, and the appropriateness of system capacity. The purpose of reading the PVSyst manual is not only to understand what the screens mean but also to be able to convey the results to others.

How to Use the PVSyst Manual in Practice

To apply the PVSyst manual in practical work, rather than aiming for a perfect simulation from the outset, it is effective to adopt a phased approach that incrementally improves accuracy. In the initial stage, use the site location, approximate system capacity, representative meteorological data, and provisional load conditions to grasp general trends. Then, as demand data, roof plans, shading conditions, selected equipment, and grid conditions become clear, update the input conditions.

In the initial study, emphasize comparing multiple options. Rather than refining a single option in detail, comparing different capacities, orientations, and ways of handling surplus power makes it easier to identify the appropriate scale for a self-consumption system. For example, the roof-maximum-capacity option may produce too much surplus, but reducing capacity slightly can greatly improve the self-consumption rate. Even when you are not yet familiar with operating PVSyst, adopting a comparative perspective brings result interpretation closer to practical practice.

In the mid-term study, improve the accuracy of load data and design conditions. If 30-minute or 1-hour power consumption data are available, evaluating time-of-day self-consumption becomes easier. If the roof layout and shading conditions are clarified, the accuracy of the generation estimates also improves. Once the modules and inverters planned for use are decided, the study can be tailored to the equipment characteristics. At this stage, it is important to confirm the meaning of each input item one by one while referring to the PVSyst manual.

In the final review, we check the consistency of the report and the clarity of the explanatory materials. We reassess whether the input conditions, output results, economic calculations, and proposed measures are consistent. For example, we check whether PVSyst shows a large surplus while the proposal materials are presented as if all generation can be self-consumed; whether surplus revenue from exported power is being assumed despite an assumption of no reverse flow; and whether outdated demand data are being presented as the latest operating conditions. Such consistency checks are extremely important in practice.

Moreover, if post-commissioning verification is taken into account, the value of PVSyst increases further. By comparing simulated and measured values, you can identify the impacts of differences in solar irradiance, soiling, shading, equipment downtime, and load fluctuations. For self-consumption systems, not only the amount of generation but also how much purchased electricity was actually reduced is important. Comparing monitoring data after installation with simulation results will also help improve the accuracy of the next project.

The PVSyst manual can be used not only as a reference for checking how to operate the software but also as a guide for organizing the study process. If you understand what to enter on each screen, how to interpret the results, and which conditions affect the self-consumption assessment, you can make proposals that go beyond mere software operation. For self-consumption solar PV systems, the ability to connect the generation side with the demand side is required. In that sense, mastering PVSyst contributes not only to design accuracy but also to improved proposal capability.

Summary

When considering self-consumption systems in the PVSyst manual, it is important not only to learn how to operate the generation simulation. For self-consumption systems, you need to assess the facility’s demand, generation patterns, surplus power, the effect on reducing purchased electricity, grid conditions, and future operations. Therefore, it is important to understand PVSyst’s input and output items in the context of actual business decision-making.

First, organize the project's assumptions and clarify the installation location, facility usage, demand characteristics, roof conditions, and the handling of surplus power. Next, handle electricity consumption and load profiles carefully so they reflect not only annual usage but also time-of-day demand. Furthermore, increase the reliability of power generation by aligning meteorological data, azimuth, tilt angle, shading, and temperature conditions with local conditions.

For modules, inverters, and loss settings, it is important not to rely too much on default values and to verify them according to the conditions of each project. For self-consumption systems, increasing system capacity is not always better; you need to consider an appropriate scale while balancing it with demand. Check the self-consumption rate, surplus power, and reduction in purchased electricity together, and by comparing multiple scenarios you can arrive at a more realistic proposal.

Finally, PVSyst reports should be used not only to produce numbers but also as material for explaining to stakeholders. If you clearly organize the assumptions, loss factors, generation, trends in self-consumption, and the time periods when surplus occurs, the report becomes an easy-to-use document for making installation decisions. Simulations do not fully guarantee the future, but by correctly organizing the conditions and properly interpreting the results, you can greatly improve the accuracy of evaluations for self-consumption solar.

When using the PVSyst manual, it is important not only to follow the on-screen operations but also to be conscious of "what does this input affect?" and "what decisions can this result be used for?". In studies of self-consumption systems, a perspective that considers generation and demand simultaneously is indispensable. If you grasp the basics and progressively scrutinize the conditions, PVSyst becomes an effective tool to support the planning, proposal, and explanation of self-consumption solar power.