Six Improvements to Increase Power Output in Solar Power Generation Simulations

Solar power generation simulations can be used not only to predict power output before installation but also to identify opportunities to increase generation. Even when annual generation is lower than expected, it is often possible to make practical improvements by reviewing layout, orientation, tilt, shading, equipment capacity, generation losses, and maintenance conditions. However, prioritizing only an increase in generation can lead to more surplus that cannot be self-consumed, poorer maintainability, and difficulties in post-construction management. This article explains, from a practical perspective for practitioners researching “solar power generation simulation,” six improvement measures to check when aiming to increase generation.

Table of contents

• Assess where there is room for improvement with simulations before trying to increase generation

• Improvement 1: Review layout to avoid shading

• Improvement 2: Optimize orientation and tilt according to site conditions

• Improvement 3: Separate areas where equipment capacity should be increased from areas where it should not

• Improvement 4: Incorporate design and maintenance to reduce generation losses

• Improvement 5: Reduce monthly and time-of-day generation variability

• Improvement 6: Increase generation value together with self-consumption and battery operation

• Points to note when comparing improvements

• Site data accuracy affects judgments on generation improvement

• Conclusion

Assess where there is room for improvement with simulations before trying to increase generation

When you want to increase generation using solar power generation simulations, the first thing to do is identify where there is room for improvement. There is rarely a single cause for low generation. It may be due to insufficient installation area, shading effects, unfavorable orientation or tilt, uneven allocation of equipment capacity, or large generation losses caused by temperature or soiling. Increasing equipment capacity alone without identifying causes can result in less improvement than expected.

In solar power generation simulations, it is important to look not only at annual generation but also at monthly generation, hourly generation, generation per installation surface, generation per unit capacity, shading losses, and the breakdown of generation losses. Even if annual generation looks low, monthly data may reveal that winter shading is the main cause. Hourly data may show that the generation curve does not rise sufficiently due to morning or evening shading. Surface-level data may reveal that a particular roof face or site area is dragging down overall efficiency.

The effectiveness of improvement measures depends on site conditions. For roof projects, there are constraints such as roof area, rooftop equipment, waterproofing, structural considerations, and inspection access routes. For land projects, there are constraints such as site boundaries, topography, row spacing, trees, drainage, and maintenance paths. You cannot simply add panels to every available space just because you want to increase generation. In simulations, you need to check the additional generation from improvements together with impacts on constructability and maintainability.

You must also consider whether increased generation leads to practical benefits. For self-consumption purposes, increasing generation may only increase surplus during times of low onsite demand, limiting electricity cost savings. When evaluating improvements to increase generation, check not only the increase in total generation but also how much self-consumption increases and how surplus energy changes.

In short, simulations to increase generation are not merely documentation to justify “making the system bigger.” They are tools to decompose causes of limited generation, numerically compare effects of improvements, and choose measures that match site conditions and operational goals. Below we go through six practical improvements to consider to increase generation.

Improvement 1: Review layout to avoid shading

The first thing to check when trying to increase generation is whether the layout avoids shading. Solar power generates from solar irradiance, and shading on panels reduces output. In particular, rooftop equipment, surrounding buildings, trees, railings, roof penthouses, piping, utility poles, signs, and terrain elevation differences cast shadows depending on time of day and season. Increasing equipment capacity while underestimating shading effects will make it hard to increase actual generation.

First, identify the sources of shading. For roof projects, check air-conditioning equipment, exhaust equipment, roof penthouses, railings, piping, inspection hatches, lightning protection equipment, and the positional relationships with surrounding buildings. For land projects, check trees, neighboring structures, utility poles, slopes, terrain elevation differences, and surrounding buildings. Not only prominent large obstacles at the site but also small upstands and equipment near the panels can affect generation.

Next, compare generation that accounts for shading with generation that does not. The difference is shading loss. Looking at monthly and hourly losses as well as annual loss helps identify when shading is significant. Because solar altitude is low in winter and shadows lengthen, shading that is negligible in summer may substantially reduce generation in winter. Morning and evening shading are also important if they coincide with the facility’s electricity demand.

To avoid shading, remove panels from highly shaded areas, shift installation areas, change panel layout, adjust row spacing, or secure clearance from surrounding obstacles. In some cases, reducing capacity slightly and concentrating on less-shaded areas can increase generation per unit capacity. Prioritizing a layout with less shading can sometimes get you closer to actual generation than simply increasing total capacity.

However, with shading-avoidance measures, also check constructability and maintainability. Overly complex layouts to avoid shading can lengthen wiring and make inspection routes difficult. For roof projects, consider waterproofing and inspection of existing equipment; for land projects, consider maintenance paths and weeding. If simulations quantify shading and identify the most shaded locations, layout improvements to increase generation become concrete. Prioritizing easily generating areas over forcing installations in shaded areas is fundamental to achieving stable long-term generation.

Improvement 2: Optimize orientation and tilt according to site conditions

The second improvement is to review orientation and tilt. the orientation and angle of solar panels greatly affect annual generation and monthly generation. Roof projects are often constrained by the existing roof’s orientation and slope, while land projects and flat roofs may allow designing the racking orientation and angle. Using solar power generation simulations to examine orientation and tilt tailored to site conditions can potentially improve generation.

Generally, orientations closer to south tend to provide higher annual generation. However, in practice, south-facing is not always the only correct choice. East-facing panels favor morning generation and west-facing panels favor afternoon generation. If a facility’s power usage is skewed toward morning or afternoon, utilizing east or west faces can be advantageous for self-consumption. It is important to consider not only maximizing annual generation but also the overlap between generation times and facility demand.

Tilt angle also affects generation. When angle can be adjusted, set it while considering seasonal variations in incident irradiance. However, increasing tilt is not always beneficial. On flat roofs or land projects, larger tilt angles can increase panel-to-panel shading and require wider row spacing. Widening row spacing reduces shading but also reduces installation capacity. It is essential to use simulations to compare the balance among angle, row spacing, equipment capacity, and generation.

For roof projects, aligning with the existing roof slope is often the basic approach. In such cases, changing the angle just because it is not ideal may not always be advisable. Adding racking can require consideration of wind effects, loads, and waterproofing. Compare the generation improvement with construction risks to determine if the change is realistic.

When reviewing orientation and tilt, check monthly generation. Changing angle may increase summer generation or improve winter generation. The optimal approach depends on which season the facility’s demand is largest. Facilities with high summer air-conditioning demand and facilities with high winter power demand will require different monthly considerations.

Optimizing orientation and tilt is not merely an exercise in increasing theoretical generation. It is a process of finding the generation pattern that best fits practical conditions by including roof shape, terrain, wind, shading, constructability, maintainability, and facility demand. Simulations allow you to compare multiple orientations and angles and numerically confirm generation improvement effects.

Improvement 3: Separate areas where equipment capacity should be increased from areas where it should not

The third improvement is to review how to increase equipment capacity. When you want to increase generation, an obvious idea is to add panels. Increasing capacity generally tends to increase annual generation. However, depending on where capacity is added, generation efficiency may be low and actual generation may not increase as much as expected. The key is to distinguish where capacity should be increased and where it is better not to.

Solar power generation simulations are useful for examining generation per unit capacity by installation surface. Adding capacity to good-condition surfaces is likely to increase generation. Conversely, adding capacity to shaded surfaces, surfaces with unfavorable orientation, unsuitable tilt, locations prone to soiling, or areas difficult to maintain may yield small gains in generation per capacity.

For roof projects, “putting panels everywhere you can” is not always optimal. Areas around rooftop equipment, near railings, around drains and inspection hatches, and areas that are likely to require waterproofing repairs need attention for construction and maintenance. Placing panels in these areas to increase generation may make later maintenance difficult.

For land projects, filling the entire site with panels increases capacity but may create issues with row shading, maintenance paths, drainage, weed control, and terrain. Too-tight row spacing can lead to front-row shadows on rear rows, especially in winter, reducing generation. It is important to separate areas to increase capacity from areas to leave spare for long-term operation.

When considering adding capacity, verify how much generation increases with additional capacity. If generation growth is small compared to the added capacity, the added portion may be inefficient. For self-consumption purposes, you also need to confirm whether the additional generation will be self-consumed or only increase surplus. If increased generation mostly becomes surplus, the practical benefit is limited.

In capacity improvements, consider appropriate capacity rather than maximum capacity. Increasing capacity in favorable areas and avoiding forcing panels into unfavorable areas improves generation efficiency and maintainability. Use simulations to compare multiple capacity scenarios and judge improvement effects by looking at generation per capacity, self-consumption, and surplus energy.

Improvement 4: Incorporate design and maintenance to reduce generation losses

The fourth improvement is to reduce generation losses. Solar generation is not determined only by irradiance and system capacity. In practice, output is reduced by temperature rise, power conversion, wiring, shading, soiling, snow, equipment downtime, and aging. Incorporating design and maintenance measures to reduce these losses leads not only to simulated generation improvements but also to maintaining actual generation in operation.

First check temperature losses. Solar panels generate electricity from sunlight, but output can decrease when panel temperature rises. Rooftops can become hot, and configurations with poor ventilation may suffer greater temperature losses. Considering installation methods, spacing under panels, and airflow can mitigate temperature rise effects.

Next, check wiring and power conversion losses. Long wiring from panels to power conversion equipment can increase losses. Reviewing equipment positioning and wiring routes can enable more efficient use of generated power. Even when simulated generation is the same, usable electrical energy may differ, so it is important to examine the breakdown of generation losses.

Soiling losses are a significant practical factor. Sand, pollen, leaves, bird droppings, and exhaust-derived dirt on panel surfaces reduce generation. Rain may wash some away, but panels on low-slope roofs, near trees, or at dust-generating facilities tend to remain dirty. To increase generation, design layouts that facilitate cleaning and inspection.

The ease of responding to equipment stoppages and anomalies also affects generation maintenance. Difficult-to-inspect layouts or hard-to-access equipment can delay detection and response to issues. A layout that appears to maximize short-term generation may lead to long-term generation declines due to poor maintainability.

To reduce generation losses, consider design-stage measures and operational maintenance together. In simulations, do not simply set loss rates lower to raise generation; confirm that specific design and management practices exist to achieve reduced losses. Increasing generation means not raising initial estimates but creating a condition that can maintain generation over the long term.

Improvement 5: Reduce monthly and time-of-day generation variability

The fifth improvement is to reduce monthly and time-of-day generation variability. Even if the annual total is the same, generation concentrated in specific seasons or times of day may not align with facility demand, reducing practical benefits. When improving generation, it is important to consider not only total generation but also the balance of when generation occurs.

Monthly variability arises from seasonal irradiance, shading, snow, temperature, and weather. When shading increases in winter, not only does annual generation fall but self-consumption effects for winter demand may be small. For facilities with high winter demand, improving winter generation is important. Possible measures include prioritizing less-shaded surfaces, adjusting row spacing, and excluding areas with significant winter shading.

Time-of-day variability is caused by orientation and shading. South-centered layouts tend to generate around midday, while combining east and west faces can supplement morning and afternoon generation. If a facility’s demand is concentrated in the morning or afternoon, matching generation time-of-day to demand increases practical generation value.

Checking generation curves per installation surface is effective for reducing variability. Knowing which surfaces generate when and when shortages occur reveals directions for layout improvements. For example, a facility with large morning demand but insufficient morning generation may benefit from using east-facing surfaces or avoiding morning shading. Facilities with large afternoon demand may need west-facing surfaces or afternoon shading countermeasures.

Reducing variability also relates to battery storage use. If large daytime surplus occurs and demand is in the evening, batteries can shift power to evening or night. But when variability is large and surplus is unstable, battery charge levels will be unstable too. Simulations should assess how generation variability affects battery charging and discharging.

Improving generation is not just about maximizing peak generation. Reducing variability to generate when needed increases chances of boosting self-consumption and reducing electricity costs. Reviewing monthly and hourly generation data enables a more practical evaluation of generation improvements.

Improvement 6: Increase generation value together with self-consumption and battery operation

The sixth improvement is to reassess not only generation itself but also how generated power is used. When using solar power generation simulations to increase generation, focusing solely on annual generation can simply increase surplus. Considering self-consumption and battery operation together can increase the value of generated electricity.

For self-consumption, what matters is the amount of generated energy that can be used onsite. If generation increases during times with no onsite demand, it becomes surplus. Therefore, when evaluating improvements, verify how much self-consumption will increase. If total generation increases but self-consumption does not, consider reviewing system capacity or operation methods.

It is also important to check facility operating hours. Facilities with daytime power demand can directly use solar generation more easily. Facilities with holidays, lunch breaks, or seasonal shutdowns may see increased surplus despite higher generation. Simulations should reflect weekday/holiday, monthly, and hourly electricity usage to confirm whether generation improvements translate to actual savings.

Combining battery storage can allow using increased generation in other time periods. Storing daytime surplus for evening or night use increases self-consumption. However, batteries have charge/discharge losses and capacity limits. Confirm whether increased generation results in more battery charge-able energy or only increases surplus that cannot be absorbed when batteries are full.

When considering emergency use, the meaning of generation improvement changes. Operations focused on maximizing normal-time self-consumption differ from those that reserve a certain battery state of charge for emergencies, and simulation results will vary. Increasing generation can strengthen emergency preparedness, but because generation depends on time of day and weather, do not overestimate its capability.

Raising generation value means increasing usable electrical energy rather than simply increasing generation. In simulations, separate and check total generation, self-consumption, surplus energy, and battery charge/discharge amounts to judge whether generation improvements lead to real operational benefits.

Points to note when comparing improvements

When evaluating improvements to increase generation, it is important to compare their effects under the same assumptions. Layouts that avoid shading, orientation and tilt adjustments, adding capacity, reducing generation losses, improving variability, and combining with batteries all affect generation and operational value. However, comparing them with differing assumptions makes it difficult to identify which measures are truly effective.

First, do not judge solely by the increase in generation. One measure may significantly increase annual generation but concentrate that increase in low-demand times, making it less effective for self-consumption. Another measure may produce a smaller total increase but boost generation during high-demand times, yielding greater practical benefit.

Next, check generation per unit capacity. While adding capacity tends to increase generation, declining generation per capacity may indicate an excessive expansion. Particularly, increasing capacity in shaded or hard-to-maintain areas may cause long-term operational issues.

Align assumptions about generation losses as well. If one simulation realistically accounts for shading and soiling while another assumes low losses, you cannot compare their generation outputs directly. When comparing improvements, align variables such as irradiance, loss rates, shading treatment, electricity usage data, and battery operating conditions.

Also confirm impacts on constructability and maintainability. A layout with higher generation may still be inappropriate if it lacks inspection routes, complicates waterproofing repairs, hinders drainage, or makes weeding and cleaning difficult. Evaluating generation improvements must include post-construction management.

Improvements to increase generation should be selected based not only on numerical generation but also on usable power, operational ease, and future maintenance. Using simulations makes it easier to compare the effects and risks of each measure and choose realistic improvements that match site conditions.

Site data accuracy affects judgments on generation improvement

Accurate site data is indispensable for correctly judging which improvements will increase generation. Solar power generation simulations are calculated based on site conditions. If roof or site dimensions, orientation, tilt, obstacles, shading sources, surrounding environment, and inspection access are not accurately captured, you cannot correctly determine which improvements are effective.

For roof projects, the positions of rooftop equipment, railings, roof penthouses, piping, drains, inspection hatches, skylights, and positional relationships with surrounding buildings are important. If these are recorded accurately, it is easier to examine layouts that avoid shading and ensure inspection routes. Conversely, missing equipment on drawings or overlooked piping added later can lead to situations where simulated increases in generation require layout changes during construction.

For land projects, site boundaries, trees, utility poles, slopes, elevation differences, drainage channels, maintenance paths, and positions of surrounding structures are important. In particular, shadows from trees and terrain greatly affect judgments on generation improvements. If you change layout to avoid shading but lack accurate positional information, quantifying improvement effects becomes difficult.

The more accurate the site data, the more fairly you can compare improvements. For example, when comparing a shading-avoiding layout with a maximum-capacity layout, accurate obstacle and boundary locations make it easier to judge which is closer to actual operation. When comparing vendor proposals, sharing the same site data helps determine whether differences in generation are due to design approach or input condition differences.

Accurate site data also aids post-installation maintenance. If generation is lower than expected, you need to determine whether shading, soiling, obstacles, equipment faults, or demand changes are the cause. If installation candidate areas, obstacles, inspection routes, and surrounding structures are recorded, identifying causes becomes easier.

Deciding on improvements to increase generation cannot be done from desk calculations alone. Accurately surveying the site and reflecting that information in simulations increases the reliability of estimated improvement effects. The more you want to increase generation, the more important it is to first organize site data.

Conclusion

To increase generation using solar power generation simulations, simply enlarging system capacity is insufficient. You must comprehensively consider layout to avoid shading, optimization of orientation and tilt, how to increase capacity, reduction of generation losses, suppression of generation variability, and combinations with self-consumption and battery operation. Rather than chasing total generation, determine which improvements will lead to real operational benefits.

The first measure to address is reviewing layouts to avoid shading. Shading is a major factor that reduces generation and is caused by rooftop equipment, surrounding buildings, trees, utility poles, and terrain. Prioritizing less-shaded areas often increases generation per unit capacity more than forcing panels into shaded areas.

Next, consider optimizing orientation and tilt. While south-facing is often advantageous, utilizing east and west faces may be effective depending on facility demand timing. For tilt angles, evaluate not only generation efficiency but also row shading, wind, loads, constructability, and maintainability.

When increasing capacity, the range in which you increase is critical. Adding capacity in favorable areas is likely to improve generation, whereas expanding into shaded or hard-to-maintain areas can reduce efficiency. Use simulations to confirm appropriate capacity rather than maximum capacity that may not match site conditions and demand.

Reducing generation losses is important. Realistically account for temperature, wiring, power conversion, soiling, downtime, and aging, and address them through design and maintenance to sustain generation. Increasing generation is not about inflating initial estimates but creating conditions for long-term stable generation.

Suppressing monthly and hourly generation variability also leads to practical improvements. Increasing annual generation that simply increases surplus during low-demand hours provides limited benefits. Match generation timing with facility usage to choose improvements that better support self-consumption and electricity cost reduction.

Combining with batteries and operational strategies can increase the value of generated power. Batteries are not devices that increase generation, but they can improve self-consumption by shifting surplus to other times. Evaluate charge/discharge losses, capacity, and emergency-use policies carefully.

Finally, accurate site data is essential for properly judging improvements. If candidate installation areas, rooftop equipment, obstacles, trees, site boundaries, inspection routes, and surrounding structures are accurately recorded, simulation assumptions become clear and improvement effects become more realistic.

If you want to increase the accuracy of improvement assessments by accurately recording candidate installation areas, rooftop equipment, obstacles, trees, site boundaries, inspection routes, and surrounding structures at the site, using LRTK, an iPhone-mounted GNSS high-precision positioning device, is effective. High-precision site location data makes it easier to proceed consistently from shading-aware layout studies and capacity improvements to vendor proposal comparisons, pre-construction checks, and maintenance management. To increase generation in solar power generation simulations, you need not only desk calculations but also a system to accurately understand the site.